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1
Shargorodskiy, Serhiy, and Volodymyr Rutkevych. "INFLUENCE OF PHYSICAL AND MECHANICAL PROPERTIES OF STEM FEED AND DESIGN OF THE WORKING BODY ON THE DRIVE POWER OF THE CUTTING MECHANISM." ENGINEERING, ENERGY, TRANSPORT AIC, no. 2(113) (June 29, 2021): 38–49. http://dx.doi.org/10.37128/2520-6168-2021-2-5.
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The paper considers the problem of reducing the drive power of the mechanism for separating stalk feed from trench storages by the batch method by developing and substantiating the parameters and operating modes of the hydraulic drive system. The structure and principle of construction of a system of hydraulic drives of the mechanism for separating a portion of stem feed are proposed. This will significantly reduce the power of the used hydraulic motors by simultaneously controlling the cutting speed of the monolith of stem feed and the feed of the cutting device. The analysis of changes in the physical and mechanical properties of stalk forage (silage and haylage), depending on the height of occurrence in the trench storage, has been carried out. The process of separation of the stalk feed from the feed monolith is considered. The complexity of the technological process of separating the portion of the stalk feed from the feed monolith due to the change in the physical and mechanical properties of the feed from the height in the trench storage and the lack of adaptation of the loader drive to such differences is indicated. A basic hydraulic diagram of the loader drives is proposed, which is based on the dependence of the cutting force of the material on the parameters of cutting modes. The theoretical foundations of the calculation were formulated by I. Timme and later adapted to the peculiarities of the work of agricultural machinery by V.P. Garyachkin. This theory allows you to determine the cutting force on the working body of the cutter bar depending on the cutting speed, feed of the cutter bar and depth of cut. An adaptive hydraulic drive of the mechanism for separating the stalk feed is proposed, which makes it possible to coordinate the operation of the cutter bar drive with its supply. The possibility of reducing the drive power of the mechanism for separating the stalk feed to 5-6 kW when using a system of hydraulic drives with a mechanism for adapting the working bodies to their working conditions has been confirmed. The modes of operation and the possibilities of increasing energy efficiency, competitiveness of technological machines and aggregates of the agro-industrial complex, by developing and substantiating the parameters of the hydraulic drive system, are indicated.
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Nikolaiev, V. A. "Lower drive of continuous action unit to form underlying layer of road." Russian Automobile and Highway Industry Journal 18, no. 1 (March 30, 2021): 30–41. http://dx.doi.org/10.26518/2071-7296-2021-18-1-30-41.
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Introduction. A continuous action unit for the formation of an underlying layer is designed to increase productivity in the construction of roads and other facilities, for which it is necessary to remove the top layer of soil. In the bucket of the continuous action unit to form an underlying layer of roads provides the use of working bodies, cutting the ground with blades of knives. The cut-off soil enters the buckets. The forces attached to the bucket are considered. Theoretically reasonable total energy costs for ground cutting of one cubic meter by buckets of continuous action unit to form an underlying layer of roads requires 109 kilojoules. Based on the calculations carried out, it is possible to determine the torque, the power required for the lower drive, the transmission ratio from the hydraulic motor to the stars, to develop the design of many elements of the continuous action unit to form the underlying layer of the road.The method of research. To determine the torque, the power required for the lower drive, the transmission ratio from the hydraulic motor to the asterisks, to the projection of the bucket on the horizontal plane attached all forces are applied directed along the bucket. As a result of their addition, the total maximum traction force of moving all the boilers during their filling with soil was revealed. On the basis of this, the method of calculating the parameters of the required is given. There is a danger of the ground being poured out of the bucket when it is rotated on the leading stars of the lower drive. To check the parameters received, the bucket is rotated by 90 degrees on the leading stars of the lower drive. The forces acting on the ground, located in the bucket, at the moment of the beginning of the turn of the bucket were revealed. A system of equations has been created, on the basis of which the condition of inadmissibility of the dumping of soil from the bucket at its turn on the leading stars has been established.Results. As a result of the addition of forces directed in the course of the bucket, the total maximum traction force of moving all the boilers during their filling with the ground, traction force on the right chain and left chain is defined. Traction chains are chosen by destructive load. The torque of the lower drive, the angular speed of the drive stars, the power required for the lower drive, the transmission ratio from the hydraulic motor to the asterisk are calculated. Based on the transferable power, a gerotor motor is chosen for the lower drive of the unit. On the basis of the calculations the design of chains, support rink, chain suspension have been developed.Conclusion. Based on the calculations made, the maximum traction force of all the buckets during the period when they are filled with soil is 11,870 newtons, the torque of the lower drive is 2,362 newtonometers, the speed of the chains is 1,686 meters per second, the angular velocity of the drive stars is 8,47 radians per second, power required for lower drive is 20 kilowatts. Based on the transferable power, it is advisable to use MT-160 gerotor motor and a single-stage planetary gearbox with a transmission ratio from the hydraulic motor to the stars 7,674. The calculations made it possible to develop the design of many elements of the continuous action unit to form an underlying layer of roads.
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Luo, Zhi Bin. "Calculation of Interaction Force between Pipe and Water of HVAC." Advanced Materials Research 1046 (October 2014): 165–68. http://dx.doi.org/10.4028/www.scientific.net/amr.1046.165.
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On the basis of the pipe network hydraulic calculation of basic theory, the pipe network utilization, using graph theory and peak array build relationships and storage node and pipe sections between the pipeline node associated with the hydraulic parameters of pipe sections linked together establish a common heating pipe network hydraulic calculation models. Matrix for the model were derived solving ideas based on the finite element method and linearization method for existing node equation method to improve to get a new heating network hydraulic calculation methods common to construct a new iterative calculation equation, to improve the convergence of iterative calculation.
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Zhao, Zhong Hao, Zeng Liang Li, and Sheng Nan Lu. "The Principle and Calculation of Hydraulic Driven Downhole Twin-Screw Pump." Advanced Materials Research 201-203 (February 2011): 448–53. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.448.
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Structure composition and working principle of hydraulic driven downhole twin-screw pump are firstly introduced, and the calculation method of work and structure parameters when downhole twin-screw pump and turbine motor operate is given, and dynamic measuring process when ground power pump, turbine motor and downhole twin-screw pump coordinate is also given. The given calculation process which is derived after sufficiently considering working principle and structure features of the pump, is instructive to the design of this kind of downhole twin-screw pump, and also provides technical support for series design of hydraulic driven downhole twin-screw pump in the future.
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Jonkobilov, Ulugmurad, Sobir Jonkobilov, Ulugbek Rajabov, Toshburi Egamnazarov, and Shuhrat Xo’shiyev. "Analytical substantiation of the parameters of the directional air-hydraulic hood." E3S Web of Conferences 264 (2021): 03034. http://dx.doi.org/10.1051/e3sconf/202126403034.
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The article is about to the calculation of the main technical parameters of the directional air-hydraulic hood. It is accepted as a mathematical model of wave equations of hyperbolic type as applied to pressure pipelines of pumping stations, and analytical solutions of wave equations for different values of the polytropic exponents are proposed. Water hammer poses a danger to the normal operation of the main equipment of stations, control and measuring equipment, control devices and pressure pipelines. To damp the intensity of water hammer in the pressure pipelines of pumping stations, we have accepted an effective design of an air-hydraulic cap. When establishing the strength indicators of pressure pipelines against hydraulic shock, it is necessary to make an accurate calculation of the main parameters of the proposed design of the air - hydraulic cap. The article presents the results of analytical and experimental studies of the accepted cap design. At the same time, an analytical method is proposed for calculating the basic dimensions of the cap. The results of the proposed calculation procedure are in good corresponding with the experimental data. This confirms the reliability of the proposed analytical calculation method.
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Hou, Jiaoyi, Hongyu Sun, Aoyu Xu, Yongjun Gong, and Dayong Ning. "Fault diagnosis of synchronous hydraulic motor based on acoustic signals." Advances in Mechanical Engineering 12, no. 4 (April 2020): 168781402091610. http://dx.doi.org/10.1177/1687814020916107.
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Synchronous hydraulic motors are used in high load conditions. Therefore, the failure of such motors must be promptly detected to avoid severe accidents and economic loss. The automation of signal processing and diagnostic processes in practical engineering applications can help improve engineering efficiency and reduce hazards. As a non-contact acquisition signal, an acoustic signal has easier acquisition than a vibration signal. This article proposes an automatic fault detection method for synchronous hydraulic motors, which uses acoustic signals. The proposed method includes the automatic calculation and pattern recognition of the parameters of fault feature vectors. The automatic calculation of the fault feature vector is based on the combination of wavelet packet energy and the Pearson correlation coefficient. Then, the nearest-neighbor classifier is used for fault diagnosis. This study verifies that the proposed method can effectively identify the normal state, gear wear, gear rust, and barrier block wear. This method provides a solution for the automatic fault diagnosis of synchronous hydraulic motors and other types of quasi-period rotating machinery.
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Blashchuk, M. Yu, Anton A. Kazantsev, and R. V. Chernukhin. "Capacity Calculation of Hydraulic Motors in Geokhod Systems for Justification of Energy-Power Block Parameters." Applied Mechanics and Materials 682 (October 2014): 418–25. http://dx.doi.org/10.4028/www.scientific.net/amm.682.418.
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The paper provides description of an approach to calculate main parameters of energy-power block of geokhod computing the hydraulic motor capacity of each end user. The paper determines the effect of geokhod dimensions on capacity consumption by main geokhod systems. The shares of capacity consumed in each geokhod system are calculated.
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Wu, Bao Gui, Shu Fa Yan, and Shao Ping Li. "Hydraulic Excavator Working Device Simulation Based on Virtual Prototype." Advanced Materials Research 1037 (October 2014): 49–52. http://dx.doi.org/10.4028/www.scientific.net/amr.1037.49.
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In order to observe the kinematic characteristic and dynamic characteristic of working state of hydraulic excavator, and aim at the complexity and time consuming of the numerical calculation and field test, the hydraulic excavator working device motion simulation and analysis scheme is put forward. By kinematics simulation, the envelope trajectory of the manipulator and the basic working parameters are got; by dynamics simulation, the force of each hinge in symmetrical and offset loadings is got, and the most hazardous working condition and hinge are determined. Thus provided the basis for strength analysis and design optimization of hydraulic excavator working device. Accordingly, a simulation analysis method to study the dynamics of the working device in hydraulic excavator is provided.
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Hu, Kai, and Wenyi Zhang. "Design and simulation for driving system and steering system of hydraulic chassis of rice transplanter." Advances in Mechanical Engineering 10, no. 10 (October 2018): 168781401880890. http://dx.doi.org/10.1177/1687814018808901.
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A new hydraulic chassis of rice transplanter is designed based on the paddy machinery operation requirements. Driving system adopts single pump four-motor scheme, and the anti-slide valve group is used to prevent the slippage of the shunt-wound hydraulic motors. Hydraulic steering system adopts single-way stable diverter valve for ensuring its response in time. Then, hydraulic system and components parameters are designed and calculated. The driving resistance and average slip rate are measured in paddy field. The experimental data verifies the correctness of theoretical calculation. The designed hydraulic driving system and steering system are simulated in AMESim. The simulated data, including pressure, flow, and torque, basically conform to the design requirement. The results verify the feasibility and reliability of chassis hydraulic scheme. The proposed design scheme may be extended to other vehicles for improving chassis performance.
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Milecki, Andrzej, and Dominik Rybarczyk. "Modeling and Control of Proportional Valve with Synchronous Motor." Solid State Phenomena 220-221 (January 2015): 457–62. http://dx.doi.org/10.4028/www.scientific.net/ssp.220-221.457.
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The paper describes the research results of modeling and control of proportional valve with synchronous motor type PMSM (Permanent Magnets Synchronous Motor). In the paper, a simulation model of the proposed valve was developed and described. The model included the square root flow characteristics, nonlinearity of the hydraulic actuator, valve dead zone and saturation of the flow. The study included the investigations of the basic characteristics, such as valve flow characteristic and step responses. In order to determine the basic parameters of the valve, the test stand was built, on which the new valve and the servo drive with this valve were tested. A servo drive control system was based on PLC with touch panel and inverter module. In the paper, the chosen investigations results of the valve and the servo drive system are presented and shortly discussed.
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Ashizawa, Satoshi, Toshiya Watanabe, Yuki Kamiya, Hidenori Aoki, and Takeo Oomichi. "Development of the Energy Simulator for the Water Hydraulic System Under Flow Condition Changes." Journal of Robotics and Mechatronics 23, no. 3 (June 20, 2011): 416–25. http://dx.doi.org/10.20965/jrm.2011.p0416.
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The new energy simulator we developed is based on a hydraulic servosystem dynamic flow model introducing flow coefficients determined by Reynolds number. One is the pipe flow coefficient flow determined by the Moody diagram and the other is the servovalve flow coefficient based on flow model experiments. The motor dynamic model is introduced to determine efficiency such as coil resistance or rotor viscosity loss. Leakage of the hydraulic servovalve was also determined by the leak model. The feasibility of the proposed simulator was verified using computer simulation and experiments, showing differences from conventional simulators that depend on manually set parameters such as flow coefficients. Simulation and experiment results agreed well, and the proposed simulator determines hydraulic servosystem energy consumption. New simulator concepts, calculation models, and experiment results are also discussed.
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Zhang, Cheng Hu, Na Meng, and De Xing Sun. "Anti-Blocking Technology for Urban Sewage Source Heat Pump System." Advanced Materials Research 472-475 (February 2012): 637–40. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.637.
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The extremely poor sewage quality could make the sewage heat utilization difficult. The paper introduces the content and distribution property of the sewage dirt. For the dirt properties and project experience, it proposes the two basic points of the anti-blocking technique in sewage source heat pump system: filtering surface continuous regeneration and dirt continuous reduction and the request for filtering pore size parameters. It also describes the principle of filtering surface hydraulic continuous regenerative technique and establishes its mathematical model and design method of the device. The calculation and application result indicates that filtering surface hydraulic continuous regenerative technique can guarantee the filtering effect and operation flow stable.
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Rybak, A. T., I. K. Tsybriy, S. V. Nosachev, and A. R. Zenin. "Theoretical background of hydraulic drive control system analysis for testing piston hydraulic cylinders." Vestnik of Don State Technical University 19, no. 3 (October 4, 2019): 242–49. http://dx.doi.org/10.23947/1992-5980-2019-19-3-242-249.
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Introduction. The durability and performance of hydraulic machines is determined through life tests. At that, various braking devices (mechanical, electric, hydraulic, etc.) are used for strength loading of the hydraulic motor, as a result of which a significant amount of energy is lost. This can be avoided if the method of rotational motion with energy recovery is used during life tests. This approach is applicable for hydraulic pumps, motors, and hydraulic cylinders.Materials and Methods. A test bench is presented, the design of which provides recreation of the conditions most appropriate for the field operation of hydraulic cylinders. In this case, energy recovery is possible. To solve the research problems, methods of mathematical modeling were used, the basic functional parameters of the proposed design were calculated. The determination of the pressure increment at various points in the hydraulic system is based on the theory of volumetric rigidity. When modeling the motion of the moving elements of the bench hydraulic system, the laws of rotor motion are used.Research Results. In the structure of the test bench, the cylinders in question are located in the pressure main between the hydraulic pump and the hydraulic motor. This enables to significantly reduce the bench itself and to save a significant amount of energy due to its recovery. A basic hydraulic diagram of the test bench for piston hydraulic cylinders is presented, in which the operation of the moving elements of the system is shown. A mathematical modeling of the hydraulic system of the bench is performed. A kinematic diagram of the mechanism for transmitting motion between test cylinders is shown.Discussion and Conclusions. The system of equations presented in the paper shows how the increment of pressure at the selected nodal points of the energy recovery system is determined (in particular, how the increment depends on time, reduced coefficient of volumetric rigidity, operating fluid consumption, and piston areas). The velocities of the hydraulic pistons are determined according to the kinematic scheme of the mechanical transmission of the bench. Thus it can be argued that, thanks to the solution presented in the paper, the life test results of hydraulic cylinders will adequately reflect their operation under rated duties.
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Polansky, Jiri. "Thermodynamics Cycle of Gas-Cooled Fast Reactor." Mechanics and Mechanical Engineering 22, no. 2 (August 24, 2020): 585–92. http://dx.doi.org/10.2478/mme-2018-0046.
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AbstractThis paper deals with the thermo-hydraulic aspect of gas cooled fast 4 generation reactor. The paper is focused on the comparison of direct and indirect strategy of thermodynamics cycle of helium cooled reactor from the thermodynamics and turbomachinary point of view. The analyses respect pressure looses at all major part of the equipment - reactor, heat exchanger, pipe lines, etc. The compressor and gas turbines efficiency are includes in calculation as well. The working fluid in primary circuit is helium. In the secondary circuit a mixture of helium and nitrogen is considered. The Cycle characteristic point and efficiency calculation reflects mixture properties of the real gas. Calculation point out the influence of mixture composition on the basic structural parameters of the turbines, compressor and heat exchangers. Thermodynamics cycle efficiency, specific heat input/output, heat flux and cycle work will be presented as characteristic parameters.
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Liang, Yijie, Tongjian Wang, Xin Wang, Weiquan Liang, and Xinhui Liu. "Simulation research on hydraulic hybrid assistant beam pumping unit." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 230, no. 11 (April 28, 2015): 1795–804. http://dx.doi.org/10.1177/0954406215584631.
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Conventional beam pumping units have occupied an important position in oilfield equipment due to such characteristics as simple structure, high reliability, simple operation, easy maintenance, and so on. In fact, there are about 90,000 sets of beam pumping units in China. However, the unbalanced structure of the beam pumping units cannot be entirely eliminated because of the inherent geometry and mechanical properties of four-bar linkage, that is the electromotor equivalent torque ripple cannot be absorbed or eliminated by counterweight in up-and-down travels, which causes the electromotor to work under greatly changed load rate with low power factor and high energy consumption. The mechanical relationship of a conventional beam pumping unit was derived first, and then parameters of a basic structure were optimized through dynamic optimization. On this basis, the hydraulic hybrid solution was proposed, and a secondary balance was conducted on the optimal pumping unit electrometer’s load torque. Computer simulation model was established to carry out a system dynamic analysis and the results showed that the scheme can reduce the motor load torque ripple, improve motor load rate and power factor, and reduce motor power effectively. It may bring tremendous decrease of electricity cost and have great significance for oilfield equipment energy saving, oil extraction cost reduction, and promotion of petroleum products’ competitiveness.
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Jin, Xiao Hong, Xian Bao Xiang, Lin Jiang, and Qin Fen Miao. "Rollback and Compensation for an Easy Control Hydraulic Servo Joint." Applied Mechanics and Materials 312 (February 2013): 662–66. http://dx.doi.org/10.4028/www.scientific.net/amm.312.662.
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The easy control hydraulic servo joint is a key element for a reconfigurable robot and its response and control accuracy determine the performance of the robot. With the stepping motor as the input element the main parts of joint includes a rotational valve with the double orifice and the single-vane actuator. The basic structure and the working principle of joint are introduced. The mathematic model is established and the dynamic responses are analysed by using the digit simulation. From the results of simulation, a phenomenon of rollback in the process of response of joint is observed. With the simulation, the relationships between the rollback and parameters of structure are discussed. A digit PID controller is employed to reduce the effect of rollback to a great extent.
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Lefik, Marcin, and Zbigniew Gmyrek. "Numerical modelling of a flux-barrier SynchRel motor including punching effect." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 35, no. 6 (November 7, 2016): 2022–34. http://dx.doi.org/10.1108/compel-03-2016-0090.
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Purpose Estimating the punching process’s impact on the operating parameters of an electrical motor is a special problem especially in the case of fractional power motors. The purpose of this paper is to discuss a method of numerical modelling that is useful for this case. Design/methodology/approach The proposed multi-physical FEM approach is based on using professional software in the process of modelling and determining the operating parameters of a low power motor. The basic elements of the approach are built FEM models for which the parameters characterising the damaged portions of the magnetic material were determined. The material properties of this zone were determined both by measurement and by a new analytical approach described in this paper. Findings The paper formulates the impact of punching on the operating parameters of a low power motor. Moreover, it formulates the analytical algorithm for the estimation of properties of material in damaged zones. Research limitations/implications Experimental verification will still be needed to check the model’s accuracy and applicability to various magnetic materials. Practical implications The paper provides an easy approach enabling the calculation of motor operating parameters and a simple and useful algorithm to estimate magnetic material properties in the damaged zone. Originality/value The analytical algorithm, as presented here, in conjunction with the measurement results is useful and applicable to estimating the magnetic material properties, which form the basis for accurate FEM calculation.
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Pryshlyak, Viktor, and Viktor Dubchak. "FINDING THE SIZE OF PRESSURE FORCE ON UNDERWATER HYDRAULIC STRUCTURES IN DESIGN AND AGRICULTURAL TRAINING OF SPECIALISTS." ENGINEERING, ENERGY, TRANSPORT AIC, no. 1(108) (August 27, 2020): 111–22. http://dx.doi.org/10.37128/2520-6168-2020-1-13.
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The article presents the results of scientific analytical studies that provide finding the pressure force on underwater hydraulic structures, such as, dams of hydroelectric power stations, sedimentation tanks for liquid organic fertilizers, sewage, coastal fortifications of lakes, rivers, ponds, etc. Practical experience in industrial and pedagogical activity and the analysis of inventive and scientific research of domestic as well as foreign scientists showed that constructive, technological and economic feasibility, operational safety of underwater hydraulic structures requires further analytical and calculation studies based on mathematical optimization methods. Of particular great scientific interest are the achievements of Chinese scientists. Their achievements from the calculation, design, construction and operation of hydraulic structures of small and large hydroelectric power stations are recognized by scientists, designers and manufacturers in the world. The work is based on research aimed at the mathematical justification of the parameters of a rectangular and trapezoidal airlock and a circular hatch, which is located at an arbitrary, optimally justified depth. It was taken into account that new students are enrolled in universities annually for training, they need to obtain knowledge based on the strength of the structures of objects with the use of innovative techniques based on the fundamental mathematical apparatus. The formation of professional competencies of agricultural engineers should ensure the ability to apply in their work the theoretical foundations and basic methods of physics and mathematics, hydrostatics, dynamics, fluid mechanics for the calculation and design of technical objects, and, of course, underwater hydraulic structures. Agroengineers should be able to perform strength calculations on the walls of tanks of any geometric profiles for storing liquids, as well as side walls and bottoms of hydraulic structures, bodies located in liquids.
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Benedek, Kálmán, and Gyula Dankó. "Stochastic hydrogeological modelling of fractured rocks: a generic case study in the Mórágy Granite Formation (South Hungary)." Geologica Carpathica 60, no. 4 (August 1, 2009): 271–81. http://dx.doi.org/10.2478/v10096-009-0019-y.
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Stochastic hydrogeological modelling of fractured rocks: a generic case study in the Mórágy Granite Formation (South Hungary)In connection with the Hungarian radioactive waste disposal program a detailed study of the mass properties of the potential host rock (granite) has been carried out. Using the results of this study the various parameters (orientation, length, intensity, transmissivity, etc.) describing a fracture set were estimated on the basis of statistical considerations. These estimates served as basic input parameters for stochastic hydrogeological modelling of discrete fracture networks (DFN), which is a strongly developing area of hydrology, providing geologically realistic geometry for site investigations. The synthetic fracture systems generated were tested against some (but not all) field observations. The models built up on the basis of the statistical descriptions showed the same equivalent hydraulic conductivity for the modelled region as the field measurements. In addition, the models reproduce the observed hydraulic head-scattering along vertical boreholes. On the basis of the stochastic simulations of the fracture system some input parameters for the performance assessment of the planned repository were investigated. Calculation of flows into a planned disposal tunnel indicated that if the hydraulic conductivity of the material in the tunnel is the only variable parameter then there are two thresholds: under 1×10-9m/s and above 1×10-5m/s further change of the hydraulic conductivity does not dramatically affect the inflow.
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A S, Sharan, Somashekhar S. Hiremath, C. S. Venkatesha, and S. Karunanidhi. "Investigation on the critical parameters affecting the working design dynamics of a torque motor employed in an electro-hydraulic servovalve." SIMULATION 95, no. 1 (April 16, 2018): 31–49. http://dx.doi.org/10.1177/0037549718759187.
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The torque motor is an intricate assembly in electro-hydraulic technology and plays a crucial role in converting the electrical signal into controlled mechanical output signal. It involves many precise components, such as the feedback spring, armature and its coil, permanent magnet, feed pipe, flexure shaft, jetpipe, and flexure support. The components are embedded together as a single operating component. Each component contributes to the effective dynamics of the system. The present paper proposes a novel approach to investigate the effect of critical parameters on the working design dynamics of the torque motor employed in the jetpipe electro-hydraulic servovalve. Based on the principles of mechatronics, a mathematical model is developed. The model-based design approach is employed to investigate the dynamics of the system. The required simulation parameters of the critical and precision components were obtained from solid and finite element (FE) models. The solid and FE models of the critical and precision components were first analyzed with suitable boundary and loading conditions to establish the stiffness. To validate the obtained FE results, experiments were carried out with a specially designed and fabricated test set-up. Based on the basic principle of electromagnetics, a nonlinear FE model of torque motor is analyzed for magnetic field distribution, the torque developed, and armature and jetpipe deflection for varied input current. From the results obtained, good agreement was observed between FE, simulated, and experimental values. The present novel approach enables one to improve the working design dynamics of the torque motor.
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Wang, Xu, and Xin Ma. "Preliminary results of the “four-dimensional six degrees-of-freedom” gait simulation system improvement." Foot & Ankle Orthopaedics 3, no. 3 (July 1, 2018): 2473011418S0051. http://dx.doi.org/10.1177/2473011418s00510.
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Category: Basic Sciences/Biologics Introduction/Purpose: Using computer-controlled electro-hydraulic servo technology, we studied the improved “four-dimensional six degrees-of-freedom” gait simulation system based on motor and hydraulic hybrid drive control and achieved the human body’s normal gait cycle with fresh cadavers Methods: Through the superimposed combination of a composite servo motor drive mechanism, a highly precise “four-dimensional six degrees-of-freedom” at the tibia could be achieved using fresh cadavers below the knee. At the same time, ten sets of independently controlled electro-hydraulic servo hydraulic cylinders were used to achieve the mechanical loading of the tendon and tibia to reproduce the dynamic and kinematic parameters of the normal gait cycle with the cadaver model Results: The time for the system to complete a gait cycle was controlled at approximately three seconds. The coordinate motion curve of the tibia in the six degrees-of-freedom space was consistent with the M curve of the normal gait cycle, and the measurement results of plantar stress were similar to the measurement curves of the normal gait cycle. Conclusion: The improved “four-dimensional six degrees-of-freedom” gait simulation system successfully reproduced a gait cycle that was the closest to the normal gait cycle among all existing research.
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Knypiński, Łukasz. "Optimal design of the rotor geometry of line-start permanent magnet synchronous motor using the bat algorithm." Open Physics 15, no. 1 (December 29, 2017): 965–70. http://dx.doi.org/10.1515/phys-2017-0119.
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AbstractIn this paper an algorithm for the optimization of excitation system of line-start permanent magnet synchronous motors will be presented. For the basis of this algorithm, software was developed in the Borland Delphi environment. The software consists of two independent modules: an optimization solver, and a module including the mathematical model of a synchronous motor with a self-start ability. The optimization module contains the bat algorithm procedure. The mathematical model of the motor has been developed in an Ansys Maxwell environment. In order to determine the functional parameters of the motor, additional scripts in Visual Basic language were developed. Selected results of the optimization calculation are presented and compared with results for the particle swarm optimization algorithm.
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Wang, Aihong, Zhenfeng Lv, Youshan Gao, Long Quan, and Jiahai Huang. "Potential energy recovery scheme with variable displacement asymmetric axial piston pump." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 234, no. 8 (November 5, 2019): 875–87. http://dx.doi.org/10.1177/0959651819885208.
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Hydraulic systems are widely used in construction machinery and equipment. However, the energy efficiency of hydraulic system is low. In many cases, hydraulic systems output energy to lift the working device. During the lowering process, the potential energy is commonly wasted through the throttling loss of the control valve. Recovering the potential energy is an efficient way to improve the hydraulic system efficiency. In this article, theoretical analysis, simulation calculation, and experimental verification were used to study the energy recovery efficiency of a differential cylinder system controlled by variable displacement asymmetric axial piston pump. Meanwhile, the influence of the load, motor speed, variable displacement asymmetric axial piston pump swashplate angle, accumulator pressure and capacity, and other key parameters on the potential energy recovery efficiency and system performance was analyzed. The results show that the system energy consumption can be reduced effectively by using the potential energy recovery system. When the load, motor speed, pre-charge pressure and capacity of the accumulator, and swashplate angle are 440 kg, 1000 r/min, 2.5 MPa, 1.6 L, and ±5°, respectively, the system’s energy-saving effect can be up to 39.25%. Considering that only the vertical motion of the differential cylinder controlled by variable displacement asymmetric axial piston pump was analyzed, in future work, the corresponding parameter optimization and control strategy will be carried out to obtain good energy recovery effect, and the influence of accumulator pre-charge pressure on the energy-saving effect will be conducted.
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A, Mulenkova, and Demchenko I.I. "On the parameters of an industrial motor vehicle designed to transport sized coal out of the face of an open pit." Izvestiya vysshikh uchebnykh zavedenii Gornyi zhurnal 1, no. 1 (January 20, 2019): 6–13. http://dx.doi.org/10.21440/0536-1028-2019-1-6-13.
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Introduction. Sized coal production in the face of an open pit allows to reduce its prime cost by reducing transfers and backhauls. At that, the maintenance of the quantitative and qualitative characteristics of the produced coal is highly significant. For this purpose it is suggested that the coal’s transfer from the face to the daylight surface ought to be carried out in specialized containers installed on an industrial motor vehicle being the initial link in the resource-saving and ecological technology of sized coal transportation out of the face of an open pit. The research aims to determine and substantiate the parameters of an industrial motor vehicle for sized coal transportation in specialized containers out of the face to the daylight surface. Methodology. An industrial motor vehicle parameters determining mathematical model have been worked out, which allows to determine the rational values of its carrying capacity and structural parameters. Research methods include mathematical modeling and analysis, computer calculation software tools, and physical modeling. Results. The present work has determined the range of parameters and the alternatives of structural variants of an industrial motor vehicle adapted for the specialized containers with sized coal transportation out of the face of an open pit. Interdependences between its basic parameters among themselves and between its basic parameters and external factors have been examined. The dependences between the carrying capacity and the productivity of processing equipment, time of sized coal loading into the containers, and the dimensions of a freight platform. Conclusions. Dependences derived in the present work allow to determine rational values of industrial motor vehicle parameters and come into the substantiation of excavating and loading equipment and processing equipment for co-operation in the process chain of coal production in the face of an open pit.
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Stryczek, Jarosław, and Piotr Stryczek. "Synthetic Approach to the Design, Manufacturing and Examination of Gerotor and Orbital Hydraulic Machines." Energies 14, no. 3 (January 26, 2021): 624. http://dx.doi.org/10.3390/en14030624.
Full textAbstract:
Gerotor technology is an important research area in the field of hydraulics which attracts the attention of both academic scientists and industry. Despite the numerous publications announced by academics, as well as a considerable number of projects made by industry, the subject has not been exhausted. This paper presents a new approach to gerotor technology which has been formed by gathering the authors’ knowledge of gerotors in a synthetic form. The following scientific and technical results have been obtained: (1) A uniform system of parameters and basic concepts regarding toothing and cycloidal gearing (z, m, λ, v, g) which is consistently used to describe the geometry, kinematics, hydraulics and manufacture of those elements; (2) description of the geometry and kinematics of the epicycloidal and hypocycloidal gears with the use of the adopted system of parameters. Additionally, the epicycloidal/hypocycloidal double gearing is presented, which is an original idea of the authors; (3) description of the hydraulics of the gerotor and orbital machines, and in particular: (i) determination of equations for delivery (capacity) q and irregularity of delivery (capacity) δ using the above-mentioned system of basic parameters; (ii) formulation of the principles of designing internal channels and clearances in the gerotor machines and presentation of the original disc distributor in the epicycloidal/hypocycloidal orbital motor; (iii) presentation of the methods of manufacturing the epicycloidal and hypocycloidal gearings with 12 examples of the systems implemented in practice; (4) presentation of the research methods applied for the examination of the gerotor machines, combining computer simulation and experimental research into a coherent and cohesive whole which results in the effect of research synergy. Such a synthesis of knowledge may serve the improvement, creation and investigation of gerotor and orbital machines carried out by academics and industry.
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Guo, Hai Qing, Bo Wen, and Xiao Feng Bai. "Study of Seepage Properties of Fractured Rock Mass Based on Improved K-Means Clustering Algorithm." Applied Mechanics and Materials 405-408 (September 2013): 310–15. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.310.
Full textAbstract:
Seepage properties of fractured rock mass are of prime importance for hydraulic engineering and accurate description of rock fracture geometry parameters is an important and basic task in rock hydraulics. In this paper, an improved K-means clustering algorithm for structural plane of fractured rock mass was first brought forward and the corresponding Matlab program for discontinuity orientations partitioning was compiled and then used in the fitting analysis of dominant orientations of certain dam foundation rock mass. On this basis, combining calculation formulas of multi-group fractures, the permeability tensor and principle value was calculated for the actual dam foundation. The results provide a theoretical and computational reference for other similar projects.
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Świć, Antoni, Victor Taranenko, and Arkadiusz Gola. "Analysis of the Process of Turning of Low-Rigidity Shafts." Applied Mechanics and Materials 791 (September 2015): 238–45. http://dx.doi.org/10.4028/www.scientific.net/amm.791.238.
Full textAbstract:
A machining station, working together with a lathe, was designed and constructed for the stabilisation of the axis of low-rigidity parts in the process of machining. The basic element is a self-centring lunette with hydraulic drive, allowing part centring without any preliminary alignment. The methodology of calculation of the parameters of the “semi-finished product/supports” subsystem is given. The effect of various schematics of support arrangements on the dynamics of the semi-finished product was analysed. The analysis of schemes of low-rigidity part fixing in the device for the stabilisation of its axis was conducted with the method of initial parameters. The choice of supports and the positioning of backstays and/or buffering steady rests was also analysed for increasing the stationary character of the process of machining and the quality of shaping the machined surface.
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Yu, Guojun, Sheng Jia, and Yanting Geng. "Numerical Investigation into the Two-Phase Convective Heat Transfer within the Hold of an Oil Tanker Subjected to a Rolling Motion." Journal of Marine Science and Engineering 7, no. 4 (April 3, 2019): 94. http://dx.doi.org/10.3390/jmse7040094.
Full textAbstract:
A crude oil tanker usually encounters a rolling motion during sea transportation, which leads to rotational movement and sometimes a sloshing of the liquid hold. This rolling-induced body motion seriously affects the thermal and hydraulic behavior of the liquid hold, which then affects the heating process and heat preservation of the tanker. Clarification of the involved thermal and hydraulic characteristics is the basic requirement for establishment of a scientific heating scheme and heat preservation method. A two-phase 3D model considering the free liquid surface and non-Newtonian behavior of the fluid was established for the thermal calculation of the liquid holds in oil tankers. The thermal and hydraulic characteristics of the liquid hold were investigated under different combinations of dimensionless parameters, and the combined effect of rolling and fluid non-Newtonian behavior was investigated. It was found that rolling intensifies the heat transfer based on the combination of the Richardson number (Ri) and the rotation-strength number (ω*), and non-Newtonian behavior of the fluid effectively affects the heat transfer in a rolling motion. This research is expected to provide a reference for design and optimization of the heating and heat preservation method for oil tanker operation.
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Riedler, Martin, Martin Stockinger, Michael Stoschka, and Wilfried Eichlseder. "Fatigue Analysis of Forged Aerospace Components Based on Micro Structural Parameters." Key Engineering Materials 348-349 (September 2007): 185–88. http://dx.doi.org/10.4028/www.scientific.net/kem.348-349.185.
Full textAbstract:
With the objective of creating a simulation model for the lifetime calculation of forged aerospace components it is necessary to clarify the damage mechanisms in the materials used. This has been researched for the Ni-base alloy Inconel 718 by varying the forging parameter effective plastic strain rate, which is realised by using three types of equipment: hydraulic press, screw press and hammer. Specimens processed at the screw press show the highest lifetime by keeping all other forging parameters unvaried. Micro structural investigations show that the amount and morphology of dominant as-large-as grains play a important role. This methodology is currently investigated for Ti-6Al-4V. Lifetime tests show that besides effective strain and anisotropy the influence of morphology is important. As soon as the model status allows lifetime analyses the thermo-mechanical process (forging and heat treatment) can be developed depending on the desired lifetime specifications in order to realise an interdisciplinary lifetime optimisation of forgings. A further aim is the use of basic coherences of safe-life and fail-safe approaches in the low and high cycle fatigue region in order to reasonable handle with flaws and defects at the edge layer.
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Skorek, Grzegorz. "Study of Losses and Energy Efficiency of Hydrostatic Drives with Hydraulic Cylinder." Polish Maritime Research 25, no. 4 (December 1, 2018): 114–28. http://dx.doi.org/10.2478/pomr-2018-0138.
Full textAbstract:
Abstract Energy efficiency of hydrostatic transmissions, and especially efficiencies of drives with motor speed controlled by throttle, as well as efficiency of hydraulic servomechanisms can in fact be higher than the efficiency values most frequently given by the respective literature in this field. With the progress achieved in recent years in the development of hydraulic systems it is becoming necessary to develop methods for precise energy efficiency calculation of such systems. It is difficult to imagine that more and more, better and better machines and control elements could be used without the possibility of a mathematical tool at our disposal to enable an accurate analysis and assessment of behavior of the system in which such machines and control elements have been applied. The paper discusses energy savings using mathematical model of losses in elements, the energy efficiency of the system. There are possibilities to reduce energy losses in proportional control systems (in the pump, in the throttle control unit, especially in the cylinder), and thus to improve the energy efficiency of the throttling manifold. The considerations allow for comparison of the loss power resulting from the applied hydraulic control structure of the hydraulic cylinder and the power consumed by the pump from the electric motor that drives it, the power necessary to provide pump-driven hydraulic cylinder. The article shows the impact on the output (useful) power consumed in the considered systems, and the impact on the power consumed of the loss power in the individual elements. The paper presents also formulas of loss power, formulas of energy efficiency connected with investigated hydrostatic drives, two schematic diagrams of hydraulic systems, their principle of operation and problems of studying losses in elements and energy efficiency characteristics of systems consisting of a feed assembly, control set and cylinder. It also includes a subject matter connected with an energy loss power of hydrostatic systems with hydraulic cylinder controlled by proportional directional control valve. Diagrams of loss power of two hydraulic systems worked at the same parameters of speed and load of a cylinder, which were different due to structure and ability of energy saving, were presented and compared.
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Novikov, S. G., V. N. Kutsenko, V. V. Malykhin, and R. W. Glagolev. "HYDRO-PULSE DEVICE FOR OBTAINING HIGH-PRESSURE LIQUID-CURRENT PRESSURES AND THE THEORETICAL ANALYSIS OF ITS WORK." Proceedings of the Southwest State University 22, no. 6 (March 27, 2019): 30–39. http://dx.doi.org/10.21869/2223-1560-2018-22-6-30-39.
Full textAbstract:
Unsteady processes in the working fluid lead to the receipt of both hydraulic impulses and hydraulic shocks, the energy of which is currently used in a number of devices and machines. In hydraulic vibratory presses, hydraulic hammers, hammers and hydraulic perforators, the creation of significant pulses is necessary to ensure their basic functions. Hydraulic impact is used in hydrotarans for water lifting and rock destruction, drilling units for drilling wells with the help of a longitudinal shock impulse, hydroimpulse plants for cleaning surplus materials (liquidations), causing irregularities in the shape and precision of the parts. Devices - multipliers for obtaining ultra-high pressures of the working fluid, providing its impulse delivery, are provided, and the characteristics of the pulses and the periods of their action are adjustable. In the construction of hydroimpulse devices, a high-speed pulse jet is created, which leads to an increase in the efficiency and productivity of the units. Analytical studies have been carried out to determine some of the main geometric and structural relationships, the dynamic parameters of devices that use the hydrodynamic effect to create powerful hydroimpuls. Mathetical calculations, which follow from the formula of Zhukovsky N.E. for the origin of the hydraulic shock and the Bernoulli equation for the unsteady motion of the working fluid, made it possible to draw a number of practical conclusions and outline the direction of research that needed to be continued, including the use of computer technology because of the complexity of the dependencies obtained and the impossibility of transforming them to a fairly simple form. The research methodology and the calculation example are presented. The ways of improving devices are outlined. It is necessary to set up experiments to evaluate the theoretical results and the behavior of the liquid under conditions of its ultrahigh pressures.
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Dewantoro, Gunawan. "Multi-objective Optimization Scheme for PID-Controlled DC Motor." International Journal of Power Electronics and Drive Systems (IJPEDS) 7, no. 3 (September 1, 2016): 734. http://dx.doi.org/10.11591/ijpeds.v7.i3.pp734-742.
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DC Motor is the most basic electro-mechanical equipment and well-known for its merit and simplicity. The performance of DC motor is assessed based on several qualities that are most-likely contradictory each other, i.e. settling time and overshoot percentage. Most of controllers optimization problems are multi-objective in nature since they normally have several conflicting objectives that must be met simultaneously. In this study, the grey relational analysis (GRA) was combined with Taguchi method to search the optimum PID parameter for multi-objective problem. First, a L<sub>9 </sub>(3<sup>3</sup>) orthogonal array was used to plan out the processing parameters that would affect the DC motor’s speed. Then GRA was applied to overcome the drawback of single quality characteristics in the Taguchi method, and then the optimized PID parameter combination was obtained for multiple quality characteristics from the response table and the response graph from GRA. Signal-to-noise ratio (S/N ratio) calculation and analysis of variance (ANOVA) would be performed to find out the significant factors. Lastly, the reliability and reproducibility of the experiment was verified by confirming a confidence interval (CI) of 95%.
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SHLYAPKIN, Alexey S., and Alexey V. TATOSOV. "NUMERICAL AND PROGRAM IMPLEMENTATION OF A ONE-DIMENSIONAL MATHEMATICAL MODEL OF HYDRAULIC FRACTURING." Tyumen State University Herald. Physical and Mathematical Modeling. Oil, Gas, Energy 7, no. 1 (2021): 126–45. http://dx.doi.org/10.21684/2411-7978-2021-7-1-126-145.
Full textAbstract:
At present, an active policy of import substitution is being pursued, dictated by the imposed international sanctions, which creates a need for finding optimal engineering solutions, in particular, in the field of creating Russian software. In the study and design of hydraulic fracturing, they often rely on the results of modeling in specialized simulators. The appearance of the Russian products on the software market, surely, sets the correct vector of development; however, some aspects are not implemented in the existing mathematical models. The authors of this article present a model that allows considering in detail the process of movement of proppant particles in a hydraulic fracture. The chosen direction is important from the point of view of calculating the fracture cavity and refining its productivity, since the behavior of the particles has a significant effect on both the growth potential of the crack and its shape. The research methodology includes a theoretical justification of the mathematical model presented by the authors in their previous works; a description of the basic principles of selecting and constructing a numerical calculation scheme and creating a software package. The main methods of research are the methods of mathematical modeling, formed from practical problems on the estimation of geometric parameters of the crack, including the areas of continuum mechanics and fracture of solids, underground hydrodynamics. The proposed and implemented numerically mathematical model forms the basis of the authors’ software package, which allows solving the main design problems when performing hydraulic fracturing operations.
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Jeong, Heon-Sul, and Hyoung-Eui Kim. "Experimental Based Analysis of the Pressure Control Characteristics of an Oil Hydraulic Three-Way On/Off Solenoid Valve Controlled by PWM Signal." Journal of Dynamic Systems, Measurement, and Control 124, no. 1 (July 20, 2001): 196–205. http://dx.doi.org/10.1115/1.1433483.
Full textAbstract:
Pressure control characteristics of a three-way high-speed on/off oil hydraulic solenoid valve driven by a PWM signal with a fixed pulse period were theoretically and experimentally analyzed and evaluated. By virtue of its relatively low cost, small size, robustness to contamination, and simplicity of the driving circuit, the three-way on/off solenoid valve is increasingly and widely used for hydraulic pressure or position control applications. In this paper, two formulas are newly derived for the mean and the ripple amplitude of the system pressure that oscillates with the same frequency as that of the PWM driving signal. The formulas indicate that the mean pressure and the pressure ripple amplitude depend on three major system variables that are the on- and the off-times of the valve and a parameter, the system configuration coefficient a, that characterizes the overall feature of the system. The mean pressure and the ripple are then shown to depend on both the duty ratio and the carrier frequency of the PWM driving signal, which disproves Tanaka’s claim that a single variable is enough to describe two quantities. Several aspects of the formulas are discussed. The accuracy of the new formulas is verified by comparing the calculation results to corresponding experimental test results. A method is proposed to obtain the system parameters of the opening and closing-case delay times, the time constants of the valve and a. The selection criteria are established for the major design parameters of the driving signal, i.e., the duty ratio and the carrier pulse frequency, and a basic strategy is proposed on how to suppress the undesirable ripple for a hydraulic servo control system using three-way on/off solenoid valve.
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Mokaramian, Amir, Vamegh Rasouli, and Gary Cavanough. "Fluid Flow Investigation through Small Turbodrill for Optimal Performance." Mechanical Engineering Research 3, no. 1 (January 20, 2013): 1. http://dx.doi.org/10.5539/mer.v3n1p1.
Full textAbstract:
Basic design methodology for a new small multistage Turbodrill (turbine down hole motor) optimized for small size Coiled Tube (CT) Turbodrilling system for deep hard rocks mineral exploration drilling is presented. Turbodrill is a type of axial turbomachinery which has multistage of stators and rotors. It converts the hydraulic power provided by the drilling fluid (pumped from surface) to mechanical power through turbine motor. For the first time, new small diameter (5-6 cm OD) water Turbodrill with high optimum rotation speed of higher than 2,000 revolutions per minute (rpm) were designed through comprehensive numerical simulation analyses. The results of numerical simulations (Computational Fluid Dynamics (CFD)) for turbodrill stage performance analysis with asymmetric blade’s profiles on stator and rotor, with different flow rates and rotation speeds are reported. This follows by Fluid-Structural Interaction (FSI) analyses for this small size turbodrill in which the finite element analyses of the stresses are performed based on the pressure distributions calculated from the CFD modeling. As a result, based on the sensitivity analysis, optimum operational and design parameters are proposed for gaining the required rotation speed and torque for hard rocks drilling.
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Nalepa, Radosław, Karol Najdek, Karol Wróbel, and Krzysztof Szabat. "Application of D-Decomposition Technique to Selection of Controller Parameters for a Two-Mass Drive System." Energies 13, no. 24 (December 15, 2020): 6614. http://dx.doi.org/10.3390/en13246614.
Full textAbstract:
In this work, issues related to the application of the D-decomposition technique to selection of the controller parameters for a drive system with flexibility are presented. In the introduction the commonly used control structures dedicated to two-mass drive systems are described. Then the mathematical model as well as control structure are introduced. The considered structure has only basic feedbacks from the motor speed and PI type controller. Due to the order of the closed-loop system, the free location of the system’s poles is not possible. Large oscillations can be expected in responses of the plant. In order to improve the characteristics of the drive, the tuning methodology based on the D-decomposition technique is proposed. The initial working point is selected using an analytical formula. Then the value of controller proportional gain is decreasing, until the required value of overshoot is obtained. In the paper different advantages of the D-decomposition technique are presented, for instance calculation of global stability area for the selected gain and phase margin, the impact of parameter changes, and additional delay evident in the system. Theoretical considerations are confirmed by simulation and experimental results.
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Anshakov, G. P., A. V. Krestina, and I. S. Tkachenko. "Analysis of the effectiveness of the de-orbiting devices for small satellite." Spacecrafts & Technologies 4, no. 2 (2020): 72–84. http://dx.doi.org/10.26732/j.st.2020.2.02.
Full textAbstract:
At present, the use of various methods is proposed for the de-orbit of small satellite, and the most feasible and promising of them are analyzed. The task of evaluating the effectiveness of the de-orbiting system for small satellite is set, in the framework of which a criterion and basic performance indicators are formed taking into account design features. As a methodological basis for evaluating the effectiveness, the method of relative integral assessment was used. Using the developed algorithm for calculating the coefficients of the integral relative assessment for each de-orbiting method, the most effective option for constructing the system isdetermined for given priority coefficients and taking into account the imposed design restrictions. For the analysis of efficiency, fuel-free de-orbiting devices and three types of propulsion systems were chosen – electric propulsion engine, solid rocket motor and liquid engine. Efficiency analysis was carried out for devices with various mass and target characteristics, the result is the choice of the type of de-orbiting system and the calculation of its parameters. The dependence of the de-orbiting device on the purpose of the spacecraft, the altitude and inclination of the orbit of its functioning, as well as on the requirements for mass, cost and other design parameters is shown.
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Оганян, Игорь Валериевич. "МАТЕМАТИЧЕСКАЯ МОДЕЛЬ ТОПЛИВНОГО НАСОСА-РЕГУЛЯТОРА ТУРБОВАЛЬНОГО ДВИГАТЕЛЯ ВЕРТОЛЕТА." Aerospace technic and technology, no. 7 (August 31, 2020): 105–12. http://dx.doi.org/10.32620/aktt.2020.7.15.
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This article discusses the relevance of creating a mathematical model of a hydromechanical fuel regulator as the main component of the parametric diagnostics method. To understand the processes occurring during the operation of the fuel regulator, this article provides a brief description of its operation. Based on the problems solved by the diagnostic methods and the features of the fuel regulator, the basic requirements for its mathematical model are formulated and the structure of this model is determined. Several assumptions are made (one-dimensional flow of the working fluid and its zero thermal conductivity), which make it possible to significantly simplify the structure of the model and the number of simulated parameters. The mathematical model consists of idealized elements with lumped parameters (such as pressure and flow rate of the working fluid), takes into account the compressibility of the working fluid, as well as the design features of the regulator (mechanical stops, complex profiled dosing windows of spools, relay-type switches). As an example, this article contains equations for the elements with lumped parameters, interconnected by hydraulic channels in one node. The compiled mathematical model is a system of differential-algebraic equations of the first index. To solve such a system, a special implicit solver is used. The calculation of the parameters of the mathematical model for static and transient operating modes of the fuel regulator has been made. The results of calculating the model parameters in various modes are compared with the requirements for these parameters set in the technical specifications for the simulated fuel regulator. The correspondence of the calculated parameters to the values specified in the technical documentation was ensured by the selection of input parameters (tightening of springs of elastic elements, area of throttling elements, etc.). From the results obtained, it was concluded that the model makes it possible to diagnose the technical state of the fuel regulator at the stages of adjustment during production and repair, as well as at the stage of its operation.
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Wei, Jingliang, and Xianwen Gao. "Electric-Parameter-Based Inversion of Dynamometer Card Using Hybrid Modeling for Beam Pumping System." Mathematical Problems in Engineering 2018 (June 27, 2018): 1–12. http://dx.doi.org/10.1155/2018/6730905.
Full textAbstract:
Conventional fault diagnosis and production calculation of an oil well can be conducted with the surface dynamometer cards, which are obtained by load sensor installed on the horse head. This method to measure the dynamometer cards is limited by the sensor maintenance and calibration, battery replacement, and safety hazards for staff. As the basic parameter of the oil extraction industry, electric parameters have the advantages of low cost and high efficiency. So the inversions of dynamometer card with electric parameters are attracting more and more attention. In order to solve the problem of insufficient data and consider the real-time performance in the actual oil extraction process, this paper proposes a novel hybrid model which consists of two parts: the mechanism model of polished rod load and the suspension displacement calculated with the space vector equations of motor and a data-dependent kernel online sequential extreme learning machine (DDKOS-ELM) model proposed to correct the output error of the mechanism model, which improves the kernel function selection and makes it real-time. Thus, the highlights of this paper can be summed up in two points: (1) under the circumstance of the bottom dead point detection without sensors, the mechanism modeling of the polished rod load and suspension displacement has been carried out from the perspective of mathematical model of AC motor; (2) a novel data-driven model based on data-dependent kernel online sequential extreme learning machine (DDKOS-ELM) has been proposed to improve the kernel functions selection. The coefficients in the data-dependent kernel function are optimized with improved free search algorithm (IFSA). The proposed hybrid model has been applied to a normal working oil well and the prediction results show better accuracy than the pure data-driven model and mechanism model.
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Kawasaki, Haruhisa. "Special Issue on Analysis and Simulation Systems for Robotics and Mechatronics." Journal of Robotics and Mechatronics 10, no. 6 (December 20, 1998): 463. http://dx.doi.org/10.20965/jrm.1998.p0463.
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Superior analysis and simulation systems play an important part in robotics and mechatronics R&D. Developing apparatuses involves repeating planning, trial manufacture, experiments, analysis, and improvement. Simulation and analysis are now executed before trial manufacture, decreasing the number of trial manufacture, shortening development, and cutting development cost. Virtual reality is often applied to simulation, and commercialization without trial manufactures will eventually be possible. Most commercialized simulation software are being improved for general use based on software made by researchers because existing analysis and simulation do not function sufficiently and researchers are often required to develop their own analysis and simulation. Simulation developed for research thus may be used by many technical experts and researchers in the future. This special issue introduces seven reports on basic mechanism analysis developed to survey simulation research. Michisuke Jo et al. developed a mechanism kinetic analysis Motor Drive using FORTRAN and MATLAB. This article, entitled Kinematic Analysis of Mechanisms Using Motor Algebra and Graph Theory, considers kinematic analysis method using the latest drive version. Haruhisa Kawasaki et al. are developing robot analysis ROSAM II using C and Maple V. This article, entitled Symbolic Analysis of Robot Base Parameter Set Using Grobner-Basis, considers base parameter analysis of general robots with closed links. Hajime Morikawa et al. developed a robot simulator kinematically simulated by connecting graphic icons. This article, entitled Network-Based Robot Simulator Using Hierarchical Graphic Icons, considers construction of a robot simulator, kinetic analysis of multiple robot arms, dynamic analysis of forest trimmers, and an example applying remote control to space robots. Shigeki Toyama et al. developed general-use mechanism analysis simulator AI MOTION. This article, entitled Dynamic Autonomous Car Mobile Analysis Simulating Mechanical Systems Analysis, considers an autonomous car travel simulator dynamically modeling tires combined into AI MOTION. The simulator analyzes the connection of tire rigidity, car width, caster radius, and motion performance. Takayoshi Muto et al. developed dynamic behavior simulator BDSP for hydraulic systems. This article, entitled Software Package BDSP Developed to Simulate Hydraulic Systems, considers construction of BDSP that analyzes hydraulic systems using easy block diagrams. The simulator analyzes fluid line, nonlinear elements, and discrete time control. Shinichi Nakajima et al. developed a two-dimensional jaw movement simulator for clarifying the function of muscles in lower jaw motion. This article, entitled Development of 2-D Jaw Movement Simulator(JSN/SI), considers hardware and a control system for chewing food at a required force. Yoshiyuki Sankai et al., in Robot Objective Parallel Calculation and Real-time Control Using a Digital Signal Processor, consider parallel distributed and realtime control by DSP for constructing control in an actual robot. This issue discussed analysis and simulation developed for robotics and mechatronics R&D. Most systems are applicable to general-purpose situations. We hope this issue helps deepen the understanding of the status and applications of simulation research in mechatronics and promotes further development in the field.
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Kozłowski, Maciej. "Simulation method for determining traction power of ATN–PRT vehicle." Transport 33, no. 2 (October 20, 2016): 335–43. http://dx.doi.org/10.3846/16484142.2016.1217429.
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The construction of Personal Rapid Transit (PRT) vehicle made within the framework of Eco-Mobility project has been described in the present paper. Key features of the vehicles were identified – e.g. drive with three-phase linear motor with winding on the vehicle and fixed rotor in the road surface, contactless dynamic vehicle powering. Attention was paid to the difference in dynamic properties compared to rail vehicles, related to the lack of the so-called ‘centering mechanism’. A development of a nominal model for the analysis of vehicle drive properties was presented. Results of simulation studies were presented for a vehicle with running-drive system construction, planned for implementation in the city of Rzeszów (Poland). While discussing the problems of building a PRT system, there was a focus on the issue of determining power and traction of the vehicle. A methodology for determining the power and traction energy consumption of the vehicle was presented for assumed conditions of travel on road segments. Input values for the calculation of power are variables describing the curvature (or bends radii) of paths of movement between stops and the course of the current speed. Output values are total traction power or traction energy (where ‘traction’ refers to the power or mechanical work of drive forces). Three basic elements of traction power were isolated: the power of kinetic energy (for acceleration/delay of vehicle movement) basic (to offset the aerodynamic force of motion resistance at constant speed) and additional losses (to offset additional motion resistance forces operating in turns at constant speed). Due to the lack of vehicle prototypes with assumed structure, it was proposed that these components are determined via simulation. The presented results relate to the calculation of demand for power and energy for the planned test section. The scope of further work was indicated: determining the required traction characteristics of electric drive, selecting the best values for supercapacitor’s capacity in the drive system, determining the technical parameters of substation.
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Settari, A. "A New General Model of Fluid Loss in Hydraulic Fracturing." Society of Petroleum Engineers Journal 25, no. 04 (August 1, 1985): 491–501. http://dx.doi.org/10.2118/11625-pa.
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Abstract This paper gives a new formulation of fluid loss in hydraulic fracturing that is much more general than the classical theory while retaining its simplicity. The model allows many parameters to vary during filtration and can, therefore, simulate nonlinear effects. The model has been validated against laboratory data for Newtonian fluids and crosslinked gels. The results show that the finite length of the core, viscosity screenout, and shear sensitivity are important parameters that can be represented by the model. The standard analysis gives values of leakoff coefficients that will give incorrect, considerably higher leakoff when applied to field conditions. Introduction The estimate of fluid loss is an important part of a hydraulic fracturing treatment design. Although the control of fluid loss has improved with the use of modern fracturing fluids, the size of the generated fracture areas increases with the size of a job. Consequently, fluid loss can be important even in low-permeability reservoirs for large treatments. For design calculations, fluid loss has been treated in the past by use of the simplified theory proposed by Howard and Fast, which expresses the rate of filtration perpendicular to a fracture wall as a simple function of perpendicular to a fracture wall as a simple function of leakoff coefficients. The advantage of this approach, besides its simplicity, is that it can be directly (if not always correctly) related to experimental data on fluid filtration obtained in a laboratory. Apart from the correction of the derivation of the combined leakoff coefficient, very little has been done to improve the classical theory. With the recent development of a simulation approach to fracturing design, it has been recognized that fluid loss can be computed directly by solving the basic multiphase flow equations in porous media. Such an approach is more general and does not have many of the assumptions that limit the classical theory. However, the computational cost is much higher and the data required to describe the process are difficult to measure. This paper presents a generalization of the classical approach that includes the effect of several parameters that are variable in the field. The mathematical formulation includes the model of filter-cake behavior developed by the author and the results of the work of Blot et al., which improves the calculation of flow in the reservoir. The model is then formulated numerically, which allows us to introduce the effects of variable pressure, fluid viscosity, and different fluids contacting the wall in the filtration process, in accordance with real conditions during the treatment. Comparison with the experimental data of McDaniel et al. shows that the model is capable of exhibiting nonlinear behavior matching the laboratory data, which cannot be explained in terms of the previous simple theory. An important feature of the model is incorporation of the length of the core, which produces nonlinear behavior and can cause large errors in calculating the true value of the leakoff coefficient when the simple formulas are used. The new model retains the simplicity of the classical leakoff theory, although it is more comprehensive and potentially more accurate than the simulation-type potentially more accurate than the simulation-type leakoff calculations, because it is formulated in terms of measurable variables. Leak-off Models vs. Simulation The flow of fracturing fluid into the reservoir can be described, at least in principle, by the equations of multiphase flow in porous media. It would thus seem natural that an improved treatment of fluid loss would use numerical simulation of flow in the reservoir with the properties and pressure at the wall (behind the filter properties and pressure at the wall (behind the filter cake) as the boundary conditions. This approach, which we have taken in our current work, is indeed more general. It is not restricted by the assumption of one-dimensional (1D) flow, and it includes the effects of relative permeability and capillary pressure and handles changing conditions at the fracture face. However, the simulation approach also has problems. First, the process of fracture fluid filtration is more complicated than the reservoir multiphase flow. The properties of the invading fluid are greatly different from the properties of the invading fluid are greatly different from the reservoir fluid and are changing with time because of breakers, temperature changes, and mixing. The fluid can be miscible with one of the resident fluids. The proper formulation would require solution of three-phase proper formulation would require solution of three-phase flow (one phase being the fracture fluid) with relative permeability, capillary pressure, and viscosities permeability, capillary pressure, and viscosities changing with time. Even though such a formulation and solution is possible, the multiphase data are almost impossible to obtain because of the nonlinearity and instability of the gets. Consequently, one must make simplifying assumptions (e.g., the filtrate assumes the properties of the reservoir water). On the numerical level, an extremely fine grid would be required owing to usually very small penetration of the fracture fluid. SPEJ P. 491
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Antypas, I. R., A. G. Dyachenko, and B. I. Saed. "Inverse analysis method for mathematical modeling of hydrodynamic ballast in a drilling rig." Advanced Engineering Research 21, no. 1 (April 4, 2021): 43–54. http://dx.doi.org/10.23947/2687-1653-2021-21-1-43-54.
Full textAbstract:
Introduction. When organizing drilling operations, one of the major problems is the accuracy and smoothness of lowering bundles of pipes into the shaft of the drilling rig. This depends on many factors, including the operation of the hydraulic brake of the lifting device. The objectives of this work are to create and study a mathematical model of hydrodynamic ballast in a drilling rig. Using the inverse analysis method, the effect of some performance indicators on the braking torque of the hydraulic brake is studied.Materials and Methods. The experiments were performed using a laboratory setup, which is a model of a hydrobrake. Its valve was closed under various conditions to obtain several pressure values with the calculation of the braking torque when a certain weight was suspended. The real (field) operating conditions of the hydromatic brake were simulated, and the results obtained were compared. When creating a mathematical model, the inverse analysis method is used. It is based on the results of experimental measurements and provides expressing the totality of the effects of individual variables on the braking torque.Results. A mathematical model of the hydraulic brake has been created and tested. The dependence of the braking torque on the pressure, density, and viscosity of the ballast fluid is determined. The influence of each variable is determined experimentally since the dependence under consideration cannot be represented as a direct relationship. The inverse analysis method is used to obtain a set of constant values that give the optimal solution. Taking into account the standard error array and the minimum standard error, the statistical errors made during experimental measurements are considered. The physically acceptable range of values of the proposed mathematical model is visualized. Using a basic (nonlinear) mathematical model, the auxiliary braking torque of a hydrobrake is calculated as a function of pressure, density, and viscosity. The proposed model validity is established. The calculated values of the braking torque were used as a criterion of correctness. The erroneous discrepancy did not exceed 6 %. For additional testing of the model, a computational experiment simulating field conditions was performed.Discussion and Conclusions. For mathematical modeling of hydrodynamic ballast in a drilling rig, it is advisable to use the inverse analysis method. The model proposed in this paper relates the braking torque of a hydrobrake to the operating parameters of the fluid inside the ballast: pressure, viscosity, and density. The objectivity of the model is validated. An amendment to it is proposed to simulate the operation of the brake in the field. Based on the results obtained, in future studies it is advisable to test the created model in the field with a real payload.
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Liu, Mengkai, Qiuyi Fan, and Hui Guo. "Frazil ice jam risk assessment method for water transfer projects based on design scheme." Water Supply 20, no. 8 (August 25, 2020): 3038–51. http://dx.doi.org/10.2166/ws.2020.201.
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Abstract Frazil ice jam risk assessment is an important method to improve the operational safety of water transfer projects. A frazil ice jam assessment method was developed based on project design conditions to ensure the risk level of frazil ice jam. A frazil ice jam risk assessment indicator system was incorporated into the method that included three first-level indicators, such as ice production, special hydraulic structure and basic design parameters, and 17 third-level indicators for calculation analysis. Then, a standard assessment system was proposed, and an analytic hierarchy process method was used to determine the magnitude of the frazil ice jam risk. Finally, the method was used to study the Middle Route of the South-to-North Water Diversion Project (MRSNWDP) from the Guyunhe to Beijumahe canals. The results showed that all of the canal pools had frazil ice jam risk levels between III and IV, of which approximately 15% of the pools have risk level IV, and the canal pools with risk level IV were reported to have ice jam incidents, and it suggested that the ice condition prediction, engineering operation process in winter, engineering measures for disaster reduction and emergency plan refinement need to be strengthened for the pools with risk level IV. Therefore, the method of frazil ice jam risk assessment based on project design conditions can perform well in both the built-operating stage and the design stage of water transfer projects. Frazil ice jam risk prevention is a task through the full life-cycle of water project construction, it is necessary to do risk assessment work at design stage, and the work should be written into the national standard.
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Belyanovskaya, Elena, Roman Lytovchenko, Kostyantyn Sukhyy, Mikhaylo Sukhyy, Mykhailo Gubynskyi, and Irina Sykha. "Performance of adsorptive heat-moisture regenerator." Scientific Works 84, no. 1 (December 14, 2020): 98–103. http://dx.doi.org/10.15673/swonaft.v84i1.1877.
Full textAbstract:
The performance of the adsorptive heat-moisture regenerators based on the composite materials ‘silica gel - sodium acetate’ and ‘silica gel – sodium sulphate’ have been studied. The mathematical model and algorithm for determining the basic operating parameters of adsorptive regenerator in the housing and communal services sector have been further developed. The proposed algorithm which involves calculating the air volume passed through the adsorbent layer, the final absolute humidity of air near the outlet from the regenerator, the adsorption and the heat of adsorption during inflow and outflow, the final temperature of the external cold air, the air temperature after mixing the cold external air and the internal warm air in the room near the warm end of the regenerator during inflow, the air temperature after mixing of the cold external air and the warm exhaust air from the premise near the cold end of regenerator during outflow, determining the temperature and moisture efficiency factors has been completed by computing the Reynolds criterion of the adsorbent layer, the coefficient of the hydraulic resistance, the pressure loss, the consumed power of ventilator, summarized adsorption and time to achieve maximal adsorption . The adequacy of suggested mathematical model is confirmed by sufficient correlation of experimental data and calculation results with the proposed algorithm. The performance of adsorptive regenerators based on the adsorbents ‘silica gel – CH3COONa’ and ‘silica gel – Na2SO4’ has been simulated in the conditions of the conventional ventilation system of living quarters. The efficiency of adsorptive regenerators has been compared when ‘silica gel – CH3COONa’ and ‘silica gel – Na2SO4’ used. The correlation of design and efficiency of adsorptive regenerators is shown.
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Dmitriev, S. M., A. E. Khrobostov, A. A. Barinov, and V. G. Glavny. "DEVELOPMENT AND ADAPTATION OF VORTEX REALIZABLE MEASUREMENT SYSTEM FOR BENCHMARK TEST WITH LARGE SCALE MODEL OF NUCLEAR REACTOR." Devices and Methods of Measurements 8, no. 3 (September 27, 2017): 203–13. http://dx.doi.org/10.21122/2220-9506-2017-8-3-203-213.
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The last decades development of applied calculation methods of nuclear reactor thermal and hydraulic processes are marked by the rapid growth of the High Performance Computing (HPC), which contribute to the active introduction of Computational Fluid Dynamics (CFD). The use of such programs to justify technical and economic parameters and especially the safety of nuclear reactors requires comprehensive verification of mathematical models and CFD programs. The aim of the work was the development and adaptation of a measuring system having the characteristics necessary for its application in the verification test (experimental) facility. It’s main objective is to study the processes of coolant flow mixing with different physical properties (for example, the concentration of dissolved impurities) inside a large-scale reactor model. The basic method used for registration of the spatial concentration field in the mixing area is the method of spatial conductometry. In the course of the work, a measurement complex, including spatial conductometric sensors, a system of secondary converters and software, was created. Methods of calibration and normalization of measurement results are developed. Averaged concentration fields, nonstationary realizations of the measured local conductivity were obtained during the first experimental series, spectral and statistical analysis of the realizations were carried out.The acquired data are compared with pretest CFD-calculations performed in the ANSYS CFX program. A joint analysis of the obtained results made it possible to identify the main regularities of the process under study, and to demonstrate the capabilities of the designed measuring system to receive the experimental data of the «CFD-quality» required for verification.The carried out adaptation of spatial sensors allows to conduct a more extensive program of experimental tests, on the basis of which a databank and necessary generalizations will be created. The received information allows to answer a number of questions related to scaling up the results of CFD calculations at the fullscale parameters of pressurized nuclear reactors.
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Kashkanov, Andriy, Serhiy Reiko, Vasyl Diorditsa, Vitaliy Kashkanov, and Anastasia Kashkanova. "Improving the quality of auto-technical examination of road accidents in conditions of composition uncertainty." Journal of Mechanical Engineering and Transport 12, no. 2 (February 2021): 61–67. http://dx.doi.org/10.31649/2413-4503-2020-12-2-61-67.
Full textAbstract:
Decision-making in solving the problems of auto technical examination of road accidents (road accidents) is carried out in conditions of incomplete information, ie in conditions of uncertainty, which may be stochastic or fuzzy in nature, and therefore is compositional. When forming expert opinions of auto technical examination of road accident the general uncertainty is formed due to uncertainty of the chosen structure of model of road accident, experimental data, error of measuring devices, adequacy of model of road accident, uncertainty of indications of witnesses and other proofs, competence and honesty of the expert. The calculation of vehicle parameters in motor vehicle expertise in the vast majority of cases is performed without estimating the error of the results, which does not meet the requirements of the Law of Ukraine "On Metrology and Metrological Activity" and determines the relevance of improving methods of solving road accident technical examination. The paper reveals the prospects of improving the existing methods of assessing the effectiveness of braking of wheeled vehicles, as the main way to prevent accidents in road transport, which is regulated by the current Traffic Rules. The basic theoretical dependences which form a basis of the improved technique of estimation of parameters of movement of cars at braking are presented. Analysis of the results of the calculations shows that by taking into account the design of the braking system, type and condition of tires used in assessing braking efficiency, the improved technique avoids the same solutions within one category of vehicles, and taking into account stochastic and fuzzy uncertainty narrows the range of possible solutions by 49.4 %. The probability of occurrence of type I errors is reduced by 1.75-18.5%, and type II errors - by 43.1-67.8%.
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Timoshenko, V. I., V. P. Halynskyi, and Yu V. Knyshenko. "Theoretical studies on rocket/space hardware aerogas dynamics." Technical mechanics 2021, no. 2 (June 29, 2021): 46–59. http://dx.doi.org/10.15407/itm2021.02.046.
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This paper presents the results of theoretical studies on rocket/space hardware aerogas dynamics obtained from 2016 to 2020 at the Department of Aerogas Dynamics and Technical Systems Dynamics of the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine along the following lines: rocket aerodynamics, mathematical simulation of the aerogas thermodynamics of a supersonic ramjet vehicle, jet flows, and the hydraulic gas dynamics of low-thrust control jet engines. As to rocket aerodynamics, computational methods and programs (CMPs) were developed to calculate supersonic flow past finned rockets. The chief advantage of the CMPs developed is computational promptness and ease of adding wings and control and stabilization elements to rocket configurations. A mathematical simulation of the aerogas thermodynamics of a supersonic ramjet vehicle yielded new results, which made it possible to develop a prompt technique for a comprehensive calculation of ramjet duct flows and generalize it to 3D flow past a ramjet vehicle. Based on marching methods, CMPs were developed to simulate ramjet duct flows with account for flow past the airframe upstream of the air inlet, the effect of the combustion product jet on the airframe tail part, and its interaction with a disturbed incident flow. The CMPs developed were recommended for use at the preliminary stage of ramjet component shape selection. For jet flows, CMPs were developed for the marching calculation of turbulent jets of rocket engine combustion products with water injection into the jet body. This made it possible to elucidate the basic mechanisms of the effect of water injection, jet–air mixing, and high-temperature rocket engine jet afterburning in atmospheric oxygen on the flow pattern and the thermogas dynamic and thermalphysic jet parameters. CMPs were developed to simulate the operation of liquid-propellant low-thrust engine systems. They were used in supporting the development and ground firing tryout of Yuzhnoye State Design Office’s radically new system of control jet engines fed from the sustainer engine pipelines of the Cyclone-4M launch vehicle upper stage. The computed results made it possible to increase the informativity of firing test data in flight simulation. The CMPs developed were transferred to Yuzhnoye State Design Office for use in design calculations.
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Xu, Bing, Yikun Liu, Yumei Wang, Guang Yang, Qiannan Yu, and Fengjiao Wang. "A New Method and Application of Full 3D Numerical Simulation for Hydraulic Fracturing Horizontal Fracture." Energies 12, no. 1 (December 24, 2018): 48. http://dx.doi.org/10.3390/en12010048.
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The numerical simulation of hydraulic fracturing fracture propagation is the core content of hydraulic fracturing design and construction. Its simulation results directly affect the effect of fracturing, and can effectively guide the fracturing construction plan and reduce the construction risk. At present, two-dimensional or quasi-three-dimensional models are mainly used, but most of them are used to simulate the vertical fracture of hydraulic fracturing. There are errors in the application process. In this paper, a three-dimensional mathematical model, including an elastic rock mechanics equation and a material flow continuity equation, is established to simulate horizontal fracture propagation in shallow reservoirs. The emphasis of this paper is to propose a new method for solving equations. The basic idea of the iteration method has been proposed by previous scholars: Firstly, assuming that the initial pressure of each point in the fracture is uniform, the fracture height of each initial point can be obtained by using Equation (20). Using the initial height values, the pressure values at each point of continuous variation are calculated by Equation (16), and then the new fracture height values are obtained by Equation (20). Because of the equal initial pressure, this method leads to too many iterations in the later stages, which makes the calculation more complicated. In this paper, a new Picca iteration method is proposed. The iteration parameters are changed sequentially. Firstly, the distribution value of fracture height is assumed. Then, the pressure distribution value is calculated according to Equation (16). Then, the new distribution value of fracture height is obtained by bringing the obtained pressure distribution value into Equation (20). Then, the new distribution value of the fracture height is calculated according to Equation (16). The pressure distribution value completes an iteration process until the iteration satisfies the convergence condition. In addition, Sneddon’s model is introduced into the hypothesis of fracture height to obtain the maximum fracture height and assume that the initial fracture profile is a parabola. Finally, the proposed method can rapidly improve the convergence rate. Next, on the basis of investigating the solutions of previous equations, the Galerkin finite element method is used to solve the above equations. The new Picard iteration sequence method is applied to solve the height and pressure at different points in the fracture. By calculating the stress intensity factor, we can judge whether the fracture continues to extend or not, and then simulate the full three-dimensional horizontal fracture of the hydraulic fracturing expansion process. The infiltration process of three types of oil reservoirs in Daqing Changyuan oilfield is simulated. The results show that during the initial fracture stage, the radius and height of fractures increase rapidly, and the rate of increase slows down with the increase of construction time. The height and net pressure of each point in the fracture are unequal. The height and net pressure of the fracture in the wellbore reach the maximum, and gradually decrease to the front of the fracture. Compared with conventional fracturing, the fracturing-flooding percolation process has the characteristics of short fracture-making and large vertical percolation distance, which can greatly increase the swept volume of flooding fluid and thus enhance oil recovery. With the increase in the rock modulus of elasticity, the radius of fractures decreases and the height of fractures increases. With the increase in construction displacement, the radius of fractures hardly changes, the height of fractures increases, and the vertical infiltration distance of the fractures increases. It is suggested that the construction displacement should be 4.0 m3/min. In the range of fracturing fluid viscosity in the studied block, with the change of fracturing fluid viscosity, the change of fracture radius and height is not obvious. In order to further increase sweep volume, the fracturing fluid viscosity should be further reduced.
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Iskandarov, Elman Kh. "IMPROVING THE EFFICIENCY OF THE FUNCTIONING OF GAS PIPELINES, TAKING INTO ACCOUNT THE STRUCTURAL FEATURES OF GAS FLOWS." Series of Geology and Technical Sciences 447, no. 3 (June 15, 2021): 34–39. http://dx.doi.org/10.32014/2021.2518-170x.59.
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The multi-phase and different composition of gas flows during the development of offshore oil and gas-condensate fields leads to high costs of energy in the system of in-field storage and transportation of well products. The analysis of the existing storage and transportation systems of gas-condensate mixtures shows that the geophysical nature and complexity of the internal structure of the transported fluids must be taken into account when choosing the mode parameters and calculation schemes of the pipelines. High-speed gas lines can be operated in a so-called "dry" mode, in which the liquid is carried along with the gas, the pipeline profile is relatively straight, without ups and downs. In this case, the formation of so-called "stagnant zones" in the pipeline is excluded. However, if the processing depth of the gas does not allow it to be transported in a single-phase state, then the condensing gas factor manifests itself. The hydraulic characteristics of vertical ups and downs on offshore pipelines are complicated, and pipelines are often filled with water and condensate. As a result, the pressure in the pipeline increases and the location of the collection point for condensing gases away from the production site can cause major problems. If we characterize oil and gas-condensate flows as a dynamic system in which alternating structural changes take place, the question of whether these systems are fractal is of great scientific interest. Based on the change in the fractal value, it is possible to diagnose structural changes during the transportation of various systems, including condensing gases in the pipelines. In this article the modes of change of basic parameters of a gas flow (pressure, flow rate and temperature) on various lines of a gas pipeline for the purpose of the producing of diagnostic criterion for revealing of liquid inclusions as a part of transported gas are investigated in this article. It is established, that in the presence of liquid inclusions at movement of gas flows there are the structural changes peculiar to fluid systems, systems which can be identified by variations of fractal dimensions of flowcharacteristics. Studies have shown that the study of the dynamics of structural changes in gas flows can play a role in diagnosing the formation of liquid phase embryos in gas pipelines. For this purpose, diagnostics for the movement of gas streams accompanied by liquid deposits in the pipelines has been proposed.