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Sharipov, V. M., Yu S. Shchetinin, S. V. Gaev, and O. V. Troshkin. "Energy analysis of dual-flow hydromechanical gears." Traktory i sel hozmashiny 84, no. 10 (October 15, 2017): 39–49. http://dx.doi.org/10.17816/0321-4443-66342.
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Two-flow hydromechanical transmissions are becoming increasingly common in the construction of modern land transport and traction machines (tractors, automobile and high-speed crawler vehicles). This is mainly due to the desire to increase the efficiency of transmission. In order to select a dual-flow hydromechanical transmission scheme in relation to specific operating conditions, it is necessary to know the advantages and disadvantages of various schemes, their potential capabilities. The evaluation of the operation of each circuit can be made on the basis of their kinematic, power, and energy analysis. The results of the kinematic and force analysis of two-flow hydromechanical gears were previously developed by the authors of this article. In energy analysis, the following estimated parameters were used to compare the performance of the transmission: г|ГМП - efficiency of transmission; РМ - power factor in the mechanical branch of the transmission; РН - power factor on the pump wheel of the torque converter; РТ - the power factor on the turbine wheel of the torque converter. The paper considers 12 schemes of two-flow hydrome-chanical gears with a differential link at the input and output with mixed gear coupling, the results of their energy analysis are given. For each of the schemes considered, analytical dependencies of the estimated parameters on the internal parameters of the hydromechanical transmission were obtained, which were used as the characteristic k of the planetary gear set, the power transfer ratio йгт of the torque converter, and the kinematic gear ratio игмп of the hydromechanical transmission. The results of calculations performed on a computer using the external characteristic of a specific torque converter are obtained and presented in graphical form. The obtained results can be used in developing recommendations for the choice of a two-flow hydromechanical transmission scheme.
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Sharipov, V. M., Yu S. Shchetinin, S. V. Gaev, and O. V. Troshkin. "POWER ANALYSIS OF DUAL-FLOW HYDROMECHANICAL GEARS." Traktory i sel hozmashiny 84, no. 2 (February 15, 2017): 35–41. http://dx.doi.org/10.17816/0321-4443-66273.
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Dual-flow hydromechanical transmissions are becoming increasingly widespread in the designs of modern land transport and traction machines (tractors, automobiles and high-speed crawler vehicles). This happens mainly due to the desire to increase the efficiency of transmission, although the capabilities of dual-flow hydromechanical transmissions are broader. In order to select a dual-flow hydromechanical transmission scheme in relation to specific operating conditions, it is necessary to know the advantages and disadvantages of various schemes, their potential capabilities. The evaluation of the operation of each circuit can be made on the basis of their kinematic and force analysis. The article deals with 12 dual-flow schemes of hydromechanical transmission with a differential element in inlet and outlet with a mixed meshing of gears, the results of the power analysis are shown. For the estimated parameters of a double-flow hydromechanical transmission were taken: й - power ratio of a double- гмп flow hydromechanical transmission; ан - coefficient of loading of the pump wheel of the torque converter; ам -load factor of the mechanical branch of the closed transmission contour; аa - load factor of the solar gear of the three-link differential mechanism. For each of the schemes considered, analytical dependencies of the estimated parameters on the internal parameters of the hydromechanical transmission were obtained. For the parameters were used the characteristic k of planetary gear set, power йгт and kinematic игт gear ratios of torque converter. It is assumed that, at the boundaries of the range й = да and й = 0. Calculations have been performed to determine the parameters й , гмп гмп гмп ан , ам u аа for different values of k and й , results of which made possible to evaluate the potential transforming properties of the schemes of two-flow hydromechanical transmissions independently of the model of the used hydrotransformer.
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Yang, Shujun, Yong Bao, Xianzhi Tang, Xiaojuan Jiao, Deqing Yang, and Qing Wang. "Integrated Control of Hydromechanical Variable Transmissions." Mathematical Problems in Engineering 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/290659.
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A hydromechanical variable transmission (HMT) has advantages of continuous variation and high efficiency. So it is one of the ideal transmissions of heavy vehicles. The continuous speed varying process involves speed governing in range and range shift. Integrated control strategy of the HMT is proposed in this paper. The algorithm of the asymmetric saturated incremental proportional integral derivative (PID) speed control strategy in range and range shift conditions are derived. And this paper presents the range shift logic and range shift control strategies. A controller model is built in Matlab Simulink and cosimulated with the model of vehicle equipped with a two-range HMT. The HMT prototype hardware-in-the-loop simulation (HILS) platform of the integrated control strategy is built. The HILS results show that the range shift process is smooth and speed fluctuation does not happen. In the throttle stable stage, the engine speed is adjusted to the near optimal speed, and its change rules are in accordance with simulation results. The integrated control strategy is reasonable.
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Sharipov, V. M., G. O. Kotiev, Yu S. Shchetinin, M. V. Vyaznikov, S. V. Gaev, and M. G. Rozenoer. "On the selection of parameters of double-flow hydromechanical transmission for industrial and forestry tractors." Traktory i sel hozmashiny 83, no. 3 (March 15, 2016): 8–14. http://dx.doi.org/10.17816/0321-4443-66117.
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Double-flow hydromechanical transmissions are widely used in industrial and forestry tractors. The main advantage of such transmission is the higher value of the maximum efficiency coefficient in comparison with the single-flow one. The article presents a method of selection of parameters of such transmissions for industrial and forestry tractors. In this case, it considers the hydromechanical transmission with a differential unit at the input and at the output. Three-link differential devices with mixed type of gear engagement are used as the differential unit. All of the twelve possible schemes of double-flow hydrodynamical transmissions are considered. It is shown that double-flow hydrodynamical transmission has an operation mode when the torque converter turbine is rotating counter to the rotation of pump wheel. This factor is taken into account during the selection of parameters of double-flow hydrodynamical transmission. The article describes the method of construction of external characteristic of the transmission and matching of its load characteristic with the full-load curve of diesel engine. The matching is performed by three ways: the selection of required value of active diameter of torque converter; the selection of reduction ratio of matching gear; the selection of characteristic of planetary gear set. It is found that for the most common scheme of double-flow hydromechanical transmission when the characteristic of planetary gear set is reduced, its maximum efficiency coefficient is increased, the active diameter of torque converter is reduced and the relative rotation frequency of satellite gears of three-link differential device is increased. In this case, the rotation frequency of satellite gears limits the minimum value of characteristic of planetary gear set. Increasing of characteristic of planetary gear set leads to the reducing of transparency of the hydromechanical transmission and to increasing of its transformation ratio. It is shown that the double-flow hydromechanical transmission allows to utilize more fully the converting properties of engine in comparison with the single-flow one; it allows to change the torque value if external engine load is changing, that is very important for industrial and forestry tractors.
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Vyaznikov, M. V., S. V. Gaev, V. M. Sharipov, Yu S. Shchetinin, and M. Yu Esenovskiy-Lashkov. "PLOTTING OF EXTERNAL CHARACTERISTIC OF A TORQUE CONVERTER WITH COUNTER-ROTATING MODE OF TURBINE WHEEL IN DOUBLE-FLOW HYDROMECHANICAL TRANSMISSION OF AN INDUSTRIAL TRACTOR." Traktory i sel hozmashiny 84, no. 4 (April 15, 2017): 11–15. http://dx.doi.org/10.17816/0321-4443-66260.
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Double-flow hydromechanical transmissions are widely used in industrial tractors and high-speed tracked vehicles. The main advantage of this transmission is a higher value of the maximum efficiency compared to a single-flow hy-dromechanical transmission. Considered is the double-flow hydromechanical transmission of the industrial tractor D8L «Caterpillar» and the results of its bench experimental studies are presented. In this transmission, the torque converter operates in a certain rotational speed range of the driven shaft in the counter-rotating mode of the turbine wheel. In the domestic and foreign literature there are no external characteristics of torque converters with the mode of turbine wheel anti-rotation. It was not possible to obtain such external characteristics of the torque converter experimentally so far. This is due to the complexity of providing a test-bench with anti-rotation mode of the turbine wheel of the torque converter. This mode is realized only in a double-flow hydromechanical transmission. However, with its experimental test-bench studies, existing techniques did not allow plotting of an external characteristic of the for the turbine wheel counter-rotating mode. At experimental test-bench researches of a torque converter only it is also impossible to provide the mode of counter rotation of a turbine wheel. In this paper, a method is given for plotting of external characteristic of a torque converter with turbine wheel anti-rotation mode, if an external characteristic of a double-flow hydromechanical transmission is known. The validity and reliability of the proposed approach to the plotting of the external characteristic of the torque converter with turbine wheel counter rotation mode is confirmed by the results of bench experimental studies of the double-flow hydromechanical transmission and the torque converter of the industrial tractor D8L Caterpillar.
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Wang, Junyan, Changgao Xia, Xin Fan, and Junyu Cai. "Research on Transmission Characteristics of Hydromechanical Continuously Variable Transmission of Tractor." Mathematical Problems in Engineering 2020 (August 12, 2020): 1–14. http://dx.doi.org/10.1155/2020/6978329.
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This paper proposes a new transmission scheme of hydromechanical continuously variable transmission (HMCVT) for tractors. The HMCVT has 4 working ranges in each of the front and rear directions. The speed characteristic and the torque characteristic of HMCVT are theoretically derived. On the basis of HMCVT power flow direction, the Крейнeс formula is used to calculate the transmission efficiency. Then, the image analysis method is used to study the influence of parameters on the transmission efficiency of HMCVT, and the main influencing factors are found. The results of theoretical derivation demonstrate that, by coordinating control of the HST displacement ratio and the engagement conditions of shifting clutches, the stepless speed regulation of HMCVT at the tractor speed of 0–50 km/h can be realized. The proposed HMCVT has the ability to continuously transmit and change torque over all working ranges. The overall transmission efficiency of HMCVT is at a high level. To verify the theoretical derivation, Amesim simulation software is used for the modeling and simulation of HMCVT. The simulation results are consistent with the theoretical analysis results. Therefore, the HMCVT proposed in this paper has the advantages of compact structure and high transmission efficiency, and it is suitable for matching tractors.
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Kotiyev, G. O., V. V. Vasilyev, and A. V. Gorbatovskiy. "Estimation of use efficiency of automatic transmission of «torque converter - coupling - gearbox» type." Traktory i sel hozmashiny 83, no. 2 (February 15, 2016): 16–20. http://dx.doi.org/10.17816/0321-4443-66138.
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The paper describes a mathematical model for wheeled vehicle with automatic transmission of «torque converter - coupling - gearbox» type. In order to compare this type of transmission and mechanical one with same number of gears and ratios, optimal characteristics of torque converter for considered vehicle are selected. The paper presents the results of simulation of wheeled vehicle moving for both variants of gearbox in conditions involving variable resistance and moving velocity assigned by driver. Efficiency of hydromechanical transmission use is estimated.
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Zhang, Guangqing, Hengtong Zhang, Yanyan Ge, Wei Qiu, Maohua Xiao, Xiaomei Xu, and Minghui Zhou. "Mechanical Efficiency of HMCVT under Steady-State Conditions." Shock and Vibration 2021 (September 3, 2021): 1–14. http://dx.doi.org/10.1155/2021/4275922.
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Hydromechanical continuously variable transmission (HMCVT) technology has been widely used due to its advantages of ride comfort and fuel economy. The relatively uniform efficiency expression of HMCVT is obtained by studying torque and transmission ratios to reveal steady-state characteristics and predict the output torque. Mathematical models of torque ratios are derived by analyzing the HMCVT system power flow and calculating the equivalent meshing power of epicyclic gear train and efficiency for the hydraulic system. The relationship between mechanical system transmission and hydraulic system parameters is established using the torque ratios, and a mechanical system demanding surface is proposed. Two numerical examples of the HMCVT system with single and dual variable units are demonstrated to establish an effective and convenient method. The method is validated through a physical prototype TA1-02 test.
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Rybak, A. T., A. V. Ivanovskaya, P. P. Batura, and A. Yu Pelipenko. "Synchronization in multi-motor hydromechanical systems." Advanced Engineering Research 21, no. 4 (January 10, 2022): 337–45. http://dx.doi.org/10.23947/2687-1653-2021-21-4-337-345.
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Introduction. The paper submits the analysis of existing design solutions of flow dividers used to synchronize hydraulic drives of working bodies of technological and mobile machines. The market demands for multithreaded throttle flow dividers without valves with the controlled division ratio, such as multi-axle vehicle chassis, are identified. The objective of the work was to analyze the possibility and rationale for developing a throttle four-way flow divider without valves with sensing elements of the Venturi tube type. The solution should provide the synchronicity of movement (rotation) of more than three working bodies of technological and mobile machines.Materials and Methods. A patent search for the designs of hydraulic flow dividers is carried out, and systems that require the division of the hydraulic fluid flow into more than two executive bodies are considered. An upgrade option, which allows dividing the flow into four branches, is proposed for the design of a three-channel throttle flow divider without valves.Results. The urgency of developing a multithreaded throttle flow divider without valves for application in industrial and mobile machines is validated. Two types of four-flow dividers are considered, their weaknesses are indicated. It is noted that the development of a multithreaded throttle flow divider based on the designs created in 1989 and 1991 will reduce the number of hydraulic pumps and get rid of the series connection of double-flow dividers. In this way, it is possible to reduce pressure losses in the hydraulic system and implement adaptive control of hydraulic motors of multi-motor mobile machines. The possibility to obtain a divider/combiner into four flows by adding an outlet chamber connected to the membrane chamber through a channel entering the Venturi nozzle on the basis of a three-flow throttle divider is shown. The principle of operation of such equipment is described.Discussion and Conclusions. The principles of construction of throttle flow dividers without valves are considered. An upgrade option is proposed to increase the number of division channels from three to four. However, to validate the operability of this design, a numerical analysis of the various modes of operation of the divider is required — calculation of the reduced volumetric stiffness of its working cavities. The information obtained can be used to modernize the hydraulic units of technological and mobile machines, increase their reliability, manufacturability, and efficiency. The issues that need to be solved in further research are identified.
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Zenfira Huseynli, Kamran Fatalizade, Zenfira Huseynli, Kamran Fatalizade. "STUDY OF THE EFFICIENCY OF HYDROMECHANICAL PACKERS USED IN THE OPERATION OF DELICATED WELLS." ETM - Equipment, Technologies, Materials 11, no. 03 (May 23, 2022): 45–51. http://dx.doi.org/10.36962/etm11032022-45.
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The article considers the general shortcomings of packers designed for carrying out geological and technical measures in an open hole. These packer deficiencies can cause problems in the operation of wells, which leads to an increase in non-productive time or even to the loss of a well and, as a result, leads to high costs for oil and gas companies. The design of sliding support elements, centering the structure in the open hole, preventing leakage of the sealing rubber element due to the occurrence of a pressure drop, and subsequently ensuring a reliable packer break, has been studied. Key words: hydromechanical packer, wellbore, sealing element, the packer unit.
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Blake, R. W. "Hydrodynamics of swimming in the water boatman, Cenocorixa bifida." Canadian Journal of Zoology 64, no. 8 (August 1, 1986): 1606–13. http://dx.doi.org/10.1139/z86-242.
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Locomotion of a small water boatman (Cenocorixa bifida, Corixidae) was investigated employing high-speed cinematography and hydromechanical modelling based on a blade-element approach. The animal is propelled by the synchronous rowing action of its hind legs. The propulsive cycle consists of a power stroke and a recovery stroke phase. Force, impulse, power, and hydromechanical efficiency were calculated for a representative power stroke during which the mean body velocity was about 8 cms−1. A distinction is made between quasi-steady resistive and unsteady inertial (added mass) forces. The mean and maximum resistive thrust forces were calculated to be about 2.4 × 10−5 and 5.7 × 10−5 N per limb, respectively. By equating the total impulse of the power stroke for both legs (2.4 × 10−6 N s) with that of the drag force acting on the body over the same period, a drag coefficient of approximately 1.07 is inferred for the body. This value is comparable to those obtained for certain insects that operate at similar Reynolds numbers to C. bifida. The unsteady added mass force that acts in the forward direction is positive (propulsive) over most of the stroke with a mean value of about 1.17 × 10−5 N per limb, corresponding to an impulse of approximately 5.9 × 10−7Ns. The total propulsive mean force and impulse acting in the forward direction amount to about 3.6 × 10−5N and 1.8 × 10−6N s per limb, respectively, so the impulse of the forwardly directed added mass force amounts to about half that of the resistive thrust force. The total work and mean power associated with generating the resistive thrust were calculated to be about 6.7 × 10−7 J and 1.33 × 10−5 W per limb, respectively. Dividing the mean body drag power (1.4 × 10−5 W) by the total mean resistive power from both legs gave a hydromechanical efficiency of 0.52. When the mean inertial power associated with moving the body (2.3 × 10−6 W) and the added mass power required to accelerate and decelerate the legs (1.95 × 10−5 W per limb) are taken into account, the power stroke propulsive efficiency falls to 0.42. Taking the energy required to power the recovery stroke into account gives an overall propulsive cycle efficiency of about 0.40. This value is about twice that calculated in a previous study for drag-based pectoral fin rowing in the angelfish and reasons for this are suggested.
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Ihnatov, Andrii. "Analyzing mechanics of rock breaking under conditions of hydromechanical drilling." Mining of Mineral Deposits 15, no. 3 (September 2021): 122–29. http://dx.doi.org/10.33271/mining15.03.122.
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Purpose is to substantiate design factors and technological parameters of next-generation facilities of hydromechanical drilling basing upon the determined features of interaction between breaking pellets and rock mass. Methods. The studies of directionality features and bottomhole processes for rock mass breaking have been carried out using the current analytical methods and laboratory experiments. Among other things, certain mathematical and physical simulation techniques, methods of theoretical processing and interpretation of the research results under SolidWorks, Statgraphics, and Маthсаd environments, and a number of relevant instruments and materials have been applied. Following their technological sequence, the well bottomhole rock-breaking processes were simulated using a special laboratory stand equipped with a control-and-measuring unit (inclusive of a flowmeter, manometer, tachometer, and coordinate spacer among other things). Findings. Application perspectiveness of the combined techniques for rock breaking has been proved. Structural designs of the next-generation facilities for well drilling have been proposed. The pellet-impact drilling features have been analyzed from the viewpoint of its significant dynamic component during the rock mass breaking. Nature of the effect of breaking load rate on the results of bottomhole deformation processes has been identified. Efficiency of the proposed scheme to improve pellet-impact drilling based upon maximum use of a well bottomhole deformed by pellets has been proved. Measures to increase technical and technological indicators of pellet drilling have been considered. Requirements for the conditions stabilizing operation of a collar of the pellet-impact device have been outlined. Further research tendencies have been specified. Originality. It has been determined that compliance with specific geometrical and hydromechanical ratios, corresponding to the stable mode of a well sinking, is the factor required for reliable operation of hydromechanical drilling facilities. Practical implications. The results of stand-based tests as well as analytical studies may become the foundations to develop efficient engineering decision for hydromechanical well drilling with high technical and economic indicators. The data, concerning bottomhole rock breaking processes, are the basic ones to work out rational standard parameters of well sinking processes.
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Frith, H., and R. Blake. "The mechanical power output and hydromechanical efficiency of northern pike (Esox lucius) fast-starts." Journal of Experimental Biology 198, no. 9 (September 1, 1995): 1863–73. http://dx.doi.org/10.1242/jeb.198.9.1863.
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The mechanical power output and hydrodynamic efficiency of northern pike, Esox lucius, during acceleration from rest (fast-start) are calculated from hydrodynamic theory for two kinematic patterns, C-starts (used in escape) and S-starts (used in prey capture). The Weihs model is employed and modified to calculate the mechanical power produced by a fish during a fast-start. A term is included for the power required to accelerate body sections laterally. Lateral deceleration of fish body sections and their associated added mass are expressed as an active process requiring energy expenditure or as a passive process requiring no energy expenditure. In addition, two methods of calculating useful power (the power used to accelerate the virtual mass of the fish, i.e. fish body mass + longitudinal added mass, in the direction of motion), one derived from the Weihs model and the second by summing the changes in kinetic energy of the virtual mass of the fish during a fast-start, are compared and found to give similar estimates of useful power (not significantly different; differences average 22 %). Comparisons of the kinematics and performance of C- and S-starts reveal that C-starts are consistently terminated after two tail flips (stages 1 and 2) whereas S-starts continue for 3­6 tail flips (stages 3­6). In addition, acceleration during C-starts is more rapid and velocities are higher (2.3­2.8 m s-1) than during S-starts (0.8­1.8 m s-1) over the first 100 ms. However, the peak velocities achieved during S-starts and C-starts are similar over the duration of a fast-start. The superior acceleration rates achieved during the initial stages of a C-start can be explained, in part, by the use of greater maximum angles of attack, higher lateral and perpendicular velocities and larger maximum forces by the caudal fin. Hydrodynamic efficiencies for fast-starts range from 0.16 to 0.39, values that are lower than those observed during either burst-and-coast or steady swimming. Efficiencies are lower for S-starts than for C-starts during the first two tail beats. S-start efficiencies increase with each subsequent tail flip and the maximum efficiencies realised are similar to those achieved during C-starts. Power output during C- and S-starts (449.0 and 394.9 W kg-1 muscle fibre, respectively) approaches the theoretical maximum for vertebrate striated muscle (500 W kg-1). Also, the inferred muscle stress is close to the predicted optimum for maximum power output, at 30 % of the maximum isometric stress recorded for isolated fast muscle fibres. These measurements suggest that fast-start performance is near a physiological limit and is probably constrained by muscle function. The superior acceleration rates achieved by C-starts over S-starts are explained in part by differences in hydrodynamic efficiency, whereas power outputs are similar.
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Morris, M. J., G. Gust, and J. J. Torres. "Propulsion efficiency and cost of transport for copepods: a hydromechanical model of crustacean swimming." Marine Biology 86, no. 3 (1985): 283–95. http://dx.doi.org/10.1007/bf00397515.
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Бородина, Марина, and Marina Borodina. "FRICTION INFLUENCE IN KINEMATIC PAIRS OF HYDROMECHANICAL CLUTCH WITH DIFFERENTIAL DRIVING GEAR UPON DYNAMICS OF ITS OPERATION." Bulletin of Bryansk state technical university 2016, no. 4 (December 28, 2016): 75–82. http://dx.doi.org/10.12737/23167.
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Hydromechanical clutches with a differential driving gear can protect against sudden quickly growing shortterm overloads not related to emergency without triggering at the expense of a smooth moment increase on a shaft of the engine provided with the operation of hydroelastic elements in the hydrosystem of a clutch. The investigation of the friction influence in ki-nematic pairs of hydromechanical clutches with helical and toothed differential driving gears upon the dynamics of clutch operation during emergency triggering has shown that in a helical driving gear the kinetic friction in a spline connection and in a pair of “screw-nut” increases a moment on a shaft of an electric motor overloading it longer than it is admissible. It means, that such a type of clutches may be used only as elastic-damping one decreasing the dynamics of the whole dynamic system at the expense of high friction in kinematic pairs, or jointly with the protection on current as a smooth increase of a moment on a shaft of the electric motor even at the overload increasing in spurts ensured by a clutch increases protection efficiency on current. In the toothed driving gear friction in kinetic pairs is low and a driving gear does not actually experience an overload that means high efficiency of driving gear protection against rapidly growing random overloads with such a type of clutches.
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Osipov, A. V., and D. N. Kurilkin. "Assessment of the switching time and fluid type influence on the transient quality in hydro-mechanical systems." Journal of Physics: Conference Series 2131, no. 2 (December 1, 2021): 022058. http://dx.doi.org/10.1088/1742-6596/2131/2/022058.
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Abstract The number of transients in hydro-mechanical power transmissions accounts for a significant portion of the total operating time and has a significant impact on drive economy. The quality of the transients largely depends on their duration and the type of working fluid used. The purpose of the work is to analyze the transients in the hydro-mechanical system, taking into account the effect of the duration of switching processes and the type of working fluid used. Determination of transient parameters in the hydro-mechanical power transmission was performed on the basis of mathematical dependences describing the switching process of two torque converters depending on the duration of the filling and emptying process and the influence of the type of working fluid used. Analysis of the calculated characteristics of transients in hydromechanical power transmissions showed that the main factor in the switching of torque converters, is the combination of filling and emptying processes, depending on the type of working fluid used. The obtained results give grounds to propose recommendations on coordination of filling and emptying processes in order to increase the efficiency of the hydromechanical drive.
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Fish, F. E. "POWER OUTPUT AND PROPULSIVE EFFICIENCY OF SWIMMING BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS)." Journal of Experimental Biology 185, no. 1 (December 1, 1993): 179–93. http://dx.doi.org/10.1242/jeb.185.1.179.
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The power output and propulsive efficiency of swimming bottlenose dolphins (Tursiops truncatus) were determined from a hydromechanical model. The propulsive movements were filmed as dolphins swam in large pools. Dolphins swam at velocities of 1.2-6.0 m s-1. Propulsion was provided by dorsoventral oscillations of the posterior body and flukes. The maximum angle of attack of the flukes showed a linear decrease with velocity, whereas the frequency of the propulsive cycle increased linearly with increasing velocity. Amplitude was 20 % of body length and remained constant with velocity. Propulsive efficiency was 0.81. The thrust power computed was within physiological limits. After correction for effects due to swimming depth, the coefficient of drag was found to be 3.2 times higher than the theoretical minimum assuming turbulent boundary conditions. The motions of the body and flukes are primarily responsible for the increased drag. This analysis supports other studies that indicate that bottlenose dolphins, although well adapted for efficient high- performance swimming, show no unusual hydrodynamic performance.
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Messis, M., A. Benaissa, and N. Bouhamou. "Hydromechanical Characterization of Raw Earth Mortar – Stabilizing Cement and Lime." Journal of Applied Engineering Sciences 12, no. 2 (December 1, 2022): 203–8. http://dx.doi.org/10.2478/jaes-2022-0027.
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Abstract Earth-based mortars are again taking their place as building materials for plastering, rendering and repairing earth walls, not only in a sustainable context but also in terms of efficiency. Nevertheless, scientific understanding of these mortars is still scarce. This present paper reports on an experimental study, conducted at the laboratory of the university center of El-Bayadh, concerning the study of the hydro-mechanical characteristics of mortars based raw and stabilized earth. In doing so, mortars prepared with clay-sand soil, treated with cement (C) (6%, 8% and 10%), lime (L) (4%, 6% and 8%) and mortars treated with both binders (4% C+2% L, 5% C +4% L, 8% C+6% L) taking into account control mortars of raw earth, are investigated. Compressive and tensile percentage strengths, total absorption, and swelling are determined. Therefore, the obtained results in the case of total absorption test, showed significant erosion in the mortars specimens weakly stabilized with cement and those without added stabilizer. Indeed, it was observed during the swelling test that the mortars specimens weakly stabilized with cement were fragile to the erosive water and showed deterioration, especially at the edges. Furthermore, increasing the cement content from 6% to 10%, the water absorption percentage was reduced by 30%. It appears that the composition that led to a better behavior towards water is the mixed combination (8% cement + 6% lime). However, stabilization with cement confers a higher strength compared to lime powder. In fact, the maximum resistances were obtained for high cement dosages (8 and 10% respectively) and the 4% lime dosage.
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Tarasik, Vladimir Petrovich, Yury Sergeyevich Romanovich, Roman Vladimirovich Pliakin, and Olga Vladimirovna Puzanova. "EFFECT OF GEARSHIFT ALGORITHM PARAMETERS ON QUALITY AND EFFICIENCY OF AUTOMATIC CONTROL OF VEHICLE HYDROMECHANICAL TRANSMISSION." Вестник Белорусско-Российского университета, no. 3 (2018): 49–62. http://dx.doi.org/10.53078/20778481_2018_3_49.
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Yin, Qian, Hongwen Jing, Haijian Su, and Huidong Wang. "CO2 Permeability Analysis of Caprock Containing a Single Fracture Subject to Coupled Thermal-Hydromechanical Effects." Mathematical Problems in Engineering 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/1290748.
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Coupled THM (thermal-hydromechanical) processes have become increasingly important in studying the issues affecting subsurface flow systems. CO2 permeability of the fracture in caprock is a key factor that affects sealing efficiency of caprock. A new model associated with coupled THM processes that shows a good reliability was derived. Then, based on the COMSOL multiphysics software, a series of numerical calculations were performed on caprock models with a single fracture subject to coupled THM effects. Transmissivity of the fracture as a function of fracture angle, overburden pressure, fluid pressure difference, injected CO2 temperature, and the initial fracture aperture was elucidated, respectively. Average transmissivity of the fracture undergoes an increase by 1.74 times with the fracture angle (45°–90°), 2-3 orders of magnitude with the fluid pressure difference (5–30 MPa), and 4-5 orders of magnitude with the initial fracture aperture (0.05–0.5 mm), while it decreases by 3-4 orders of magnitude as overburden pressure increases from 30 to 80 MPa. Injected CO2 temperature has a small impact on the fracture permeability. This work provides an alternative tool to enrich the numerical modeling for the assessment of CO2 caprock sealing efficiency.
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Larsson, L. Viktor, Liselott Ericson, Karl Uebel, and Petter Krus. "Low-Level Control of Hybrid Hydromechanical Transmissions for Heavy Mobile Working Machines." Energies 12, no. 9 (May 4, 2019): 1683. http://dx.doi.org/10.3390/en12091683.
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Fuel efficiency has become an increasingly important property of heavy mobile working machines. As a result, Hybrid Hydromechanical Transmissions (HMTs) are often considered for the propulsion of these vehicles. The introduction of hybrid HMTs does, however, come with a number of control-related challenges. To date, a great focus in the literature has been on high-level control aspects, concerning optimal utilization of the energy storage medium. In contrast, the main topic of this article is low-level control, with the focus on dynamic response and the ability to realize requested power flows accurately. A static decoupled Multiple-Input-Multiple-Output (MIMO) control strategy, based on a linear model of a general hybrid HMT, is proposed. The strategy is compared to a baseline approach in Hardware-In-the-Loop (HWIL) simulations of a reference wheel loader for two drive cycles. It was found that an important benefit of the decoupled control approach is that the static error caused by the system’s cross-couplings is minimized without introducing integrating elements. This feature, combined with the strategy’s general nature, motivates its use for multiple-mode transmissions in which the transmission configuration changes between the modes.
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Chetverikova, I., P. Popikov, and S. Glushkov. "Improving the efficiency of manipulator-type machines with an improved hydraulic drive." IOP Conference Series: Earth and Environmental Science 875, no. 1 (October 1, 2021): 012055. http://dx.doi.org/10.1088/1755-1315/875/1/012055.
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Abstract The article considers the possibility of increasing the efficiency of manipulator-type machines when harvesting wood by increasing the productivity, energy efficiency and reliability of the hydraulic equipment used. A combined method of transporting timber from logging sites by road and water transport using equipment with an improved hydraulic drive of the manipulator is proposed. The issue has not been worked through before. Using the example of the Northwestern Federal District, the author considers the development of forest areas located in the upper reaches of small and medium rivers. For the first time, original hydromechanical dampers and energy-saving devices are used in hydraulic drives of manipulators of forest machines to reduce dynamic loads and energy consumption for loading and unloading timber. This increases the efficiency of the use of manipulator-type machines, creating mobility, reducing equipment costs, the time spent waiting for unloading on sites for further rafting or shipment. The development of forest areas in a combined way will reduce capital investments for the construction of transport routes at the border of waterways by at least 3 times. All this will reduce the cost of harvesting in general and eliminate the use of additional loaders.
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Kadochnikov, Viacheslav G., and Mikhail V. Dvoynikov. "Development of Technology for Hydromechanical Breakdown of Mud Plugs and Improvement of Well Cleaning by Controlled Buckling of the Drill String." Applied Sciences 12, no. 13 (June 25, 2022): 6460. http://dx.doi.org/10.3390/app12136460.
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The article provides brief information about a non-standard experimental setup developed in the laboratory of the St. Petersburg Mining University Well Drilling Department. The developed technique presented makes it possible to simulate well cleaning process of cuttings by incorporating the variation of the parameters (the zenith angle of the well, the volume flow and rheological properties of the cleaning agent, the rotation frequency, the number and length of the drill string half-waves) that cause buckling. For the first time, the positive side of the drill string (DS) buckling phenomenon is considered. A positive hydro-mechanical effect on mud plugs and improved well cleaning were revealed. The results of the experimental study confirm an intense difficulty in transporting cuttings to the surface at a critical zenith angle of the well of 55°. Regularities have been established making it possible to determine the effect of DS buckling on the cutting-carrying capacity when drilling deviated and extended reach wells. It is proposed to use hydromechanical impact on the accumulated cuttings by artificially controlling the resulting DS buckling in order to destroy the mud plug and increase the efficiency of well cleaning without the use of specialized devices. A conceptual solution aimed at implementing a method for hydromechanical destruction of mud plugs—the use of drill pipes equipped with a quasi-distributed differential measuring system of strain gauges based on a fiber-optic Bragg grating—is presented.
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Cheng, Zhun, Zhixiong Lu, and Fang Dai. "Research on HMCVT Efficiency Model Based on the Improved SA Algorithm." Mathematical Problems in Engineering 2019 (January 27, 2019): 1–10. http://dx.doi.org/10.1155/2019/2856908.
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Research on the efficiency characteristic of the hydromechanical continuous variable transmission (HMCVT) in tractors is key to obtaining optimal transmission, developing control strategies, and assessing efficiency. To ease and improve the accuracy of obtaining the efficiency completely based on test measurements or theoretical calculation, this study proposes a method for building the HMCVT efficiency model. The method is based on an improved simulated annealing (SA) algorithm according to a small amount of test data. The study uses 8 groups of transmission efficiency values under different operating conditions obtained from bench tests. By theoretical analysis of the HMCVT, this study divides the total transmission efficiency into (i) the transmission efficiency from the output power of the power source to the confluence mechanism, (ii) the transmission efficiency of the confluence mechanism, and (iii) the transmission efficiency of the output part after confluence. The formulas for the three parts of transmission efficiencies are then derived. This study improves the SA algorithm and uses it to identify the three key parameters of hydraulic systems of the transmission efficiency calculation model. Research results indicate that the efficiency model built using the proposed method exhibits high accuracy with an error of about 1.90%. The improved SA algorithm can rapidly complete key parameter identification with an error of about 2.16%; when the displacement ratio is 0, the efficiency values at the same stage are approximately equal under different operating conditions. The HMCVT efficiency model can be built rapidly and effectively with only five groups of efficiency measurement tests.
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Shevchenko, S. S. "Mathematical modeling of centrifugal machines rotors seals for the purpose of assessing their influence on dynamic characteristics." Mathematical Modeling and Computing 8, no. 3 (2021): 422–31. http://dx.doi.org/10.23939/mmc2021.03.422.
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With an increase of equipment parameters, such as the pressure of the sealing medium and the speed of shaft rotation, the problems ensuring its hermetization efficiency are rising up. In addition to hermetization itself, the sealing system affect the overall operational safety of the equipment, especially vibratory. Groove seals are considered as hydrostatodynamic supports capable of effectively damping rotor oscillations. To determine the dynamic characteristics, models of grooved seals and single-disc rotors with grooved seals are examined. The obtained analytical dependences for computation of dynamic characteristics for the hydromechanical rotor-seals system, describing radial-angular oscillations of the centrifugal machine rotor in groove seals are presented as well as the formulas for computation of amplitude frequency characteristics. An example for the computation dynamic characteristics of one of the centrifugal machine rotor models is drawn.
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Stephenson, R., J. R. Loworn, M. A. Heieis, D. R. Jones, and R. W. Blake. "A Hydromechanical Estimate of the Power Requirements of Diving and Surface Swimming in Lesser Scaup (Aythya Affinis)." Journal of Experimental Biology 147, no. 1 (November 1, 1989): 507–18. http://dx.doi.org/10.1242/jeb.147.1.507.
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Buoyancy and body drag were measured in lesser scaup (Aythya affinis) and the data were used to estimate average power output during diving and surface swimming. Buoyant force (mean±s.D.) of fully submerged ducks was 2.89±0.17 N (body mass 0.623±0.089kg; body volume 918±88cm3; N=11). Buoyancy was decreased by 6.2° by artificial compression of the feathers during full immersion, but was reduced by 42° when the ducks were allowed to breathe during head-out immersion. Therefore, voluntary compression of the plumage by the duck appears to have relatively small effects on buoyancy and hence dive costs, whereas alteration of respiratory volume (e.g. by pre-dive expiration) could substantiallyalter buoyancy and power requirements. Surface and subsurface body drag (DSUR and DSUB respectively, in newtons) of frozen duck carcasses increased with velocity (U, ms−1) as follows: DSUR= 0.239-1.292U+2.027U2 (r2 = 0.965), DSUB = - 0.144+0.562U + 0.622U2 (r2 = 0.980). Work required to overcome body drag is greater for a lesser scaup during diving than during surface swimming at average velocities normally attained during these activities (less than 0.7 ms−1). However, the drag force curves merge at 0.8-l.0ms−1. It is calculated that the average power output during diving ranges from 1.003 to 1.695 W and that in ducks at least 95° of the work done during a dive is required to overcome buoyancy. Comparison of these biomechanical estimates with aerobic metabolic power input (Voo2) data reported by Woakes and Butler (1983) indicates that, for freely diving ducks, aerobic efficiency (ηa=average power output/total aerobic power input) is 0.088–0.149 and net aerobic efficiency [ηnet=average power output/(total aerobic power input minus resting aerobic power input)] is 0.124–0.209. These values are significantly greater than those during surface swimming at the same velocities (ηa=0.004–0.037, ηnet=0.039–0.063).
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GASPARYAN, IRINA N. "PROBLEMS RELATED TO THE PRODUCTION OF HUMIC FERTILIZERS AND THEIR SOLUTIONS." Agricultural engineering, no. 1 (2022): 23–27. http://dx.doi.org/10.26897/2687-1149-2022-1-23-27.
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Further development of organic agricultural production requires large volumes of organic fertilizers. Due to the sharp reduction in cattle, there is a lack of organic fertilizer in the form of animal waste. To solve this problem, eleven technological lines for processing natural organic raw materials in the form of peat, brown coal, and sapropel were developed, considering customers’ technical requirements, and then delivered to some regions of Russia and Belarus. The authors analyzed the operation of these lines, and based on the study of the operation of individual units and assemblies, identified technical and technological problems. They studied and analyzed the possibilities of developing technological lines using modular equipment of machine-building organizations to process organic raw materials for making humic fertilizers. The research results made it possible to modernize individual technological lines using new innovative developments and modular equipment. Using a new design of a hydromechanical cleaner to clean the peat suspension before feeding it into the reactor increased the level of its purification to 97…98%. Reinforcement of the technological line with modular equipment (vibratory mill of MV-20 type) for grinding coal increased the quality of the reactor and reduced the ballast content after filtration to 1…3%. The dispersion of the fertilizer suspension supplied for filtration decreased to 50…70 microns. The introduction of the design of a new high-power dismembrator made it possible to reduce the production cycle time by 30 minutes. An additional installation of a hydromechanical cavitator increased the efficiency of extracting humic acids from organic raw materials. The microelement dosing system has been modernized to produce concentrated fertilizers up to 2.5 tons per shift. The research results have determined the expediency of further development of technological lines based on modular equipment.
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Shirobokova, Ol'ga, Yuriy Kisel', and Dmitriy Bezik. "APPLICATION OF ELECTRICAL TECHNOLOGIES FOR THE RESTORATION OF AGRICULTURAL MACHINERY PARTS." Bulletin of Bryansk state technical university 2021, no. 10 (October 14, 2021): 22–26. http://dx.doi.org/10.30987/1999-8775-2021-10-22-26.
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The technology of non-galvanized ironing of parts in the electrolyte flow with simultaneous hydromechanical activation of the plated surface is proposed, its advantages over the traditional type of coating are shown. The technological process of coating hydraulic control valve spools has been developed. The technological process of restoring spools consists of the following operations: preliminary surface preparation (mechanical treatment), degreasing, washing, anodic treatment, electrodeposition and final mechanical treatment. The designs of the installation and the electrochemical cell for ironing hydraulic control valve spools, providing optimal hydrodynamic conditions when applying coatings on worn surfaces, are proposed. Optimal modes and composition of ironing electrolyte have been defined, providing a high rate of precipitation growth (1.5...3 mm/h), adhesion strength and wear resistance of coatings. Bench and field tests of hydraulic valves with restored spools were performed, which confirmed the results of laboratory studies and the high efficiency of the proposed technology.
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Shirobokova, Ol'ga, Yuriy Kisel', and Dmitriy Bezik. "APPLICATION OF ELECTRICAL TECHNOLOGIES FOR THE RESTORATION OF AGRICULTURAL MACHINERY PARTS." Bulletin of Bryansk state technical university 2021, no. 10 (October 14, 2021): 22–26. http://dx.doi.org/10.30987/1999-8775-2021-10-22-26.
Full textAbstract:
The technology of non-galvanized ironing of parts in the electrolyte flow with simultaneous hydromechanical activation of the plated surface is proposed, its advantages over the traditional type of coating are shown. The technological process of coating hydraulic control valve spools has been developed. The technological process of restoring spools consists of the following operations: preliminary surface preparation (mechanical treatment), degreasing, washing, anodic treatment, electrodeposition and final mechanical treatment. The designs of the installation and the electrochemical cell for ironing hydraulic control valve spools, providing optimal hydrodynamic conditions when applying coatings on worn surfaces, are proposed. Optimal modes and composition of ironing electrolyte have been defined, providing a high rate of precipitation growth (1.5...3 mm/h), adhesion strength and wear resistance of coatings. Bench and field tests of hydraulic valves with restored spools were performed, which confirmed the results of laboratory studies and the high efficiency of the proposed technology.
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D’Andrea, Danilo, Giacomo Risitano, and Fabio Alberti. "Fuel Consumption Reduction and Efficiency Improvement in Urban Street Sweeper Using Power Split with Lockup Clutch Transmission." Applied Sciences 12, no. 19 (October 10, 2022): 10160. http://dx.doi.org/10.3390/app121910160.
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The aim of this work is to design a power split transmission for an urban street sweeper in order to reduce fuel consumption. The design process starts with the comparison between a hydrostatic and a hydromechanical power split transmission. Both transmissions have been tested through an acceleration test considering 30, 50, 70 and 100 percent of the rated engine power. The results of both models developed in the Simcenter AmesimTM environment show that the power split transmission presents a higher efficiency, which justifies the adoption of this type of transmission with respect to the hydrostatic system. Then, a pure mechanical gear is added to the base concept of the power split transmission. The mechanical gear is managed by a lockup clutch, which can be engaged during the working phase of the street sweeper, similar to an adaptive cruise control. In this case, both transmissions are tested through a regulated cycle, UNI-EN 151429-2, highlighting the advantage of using a pure mechanical branch. At the end, both transmissions are tested with a driving cycle acquired through an experimental setup consisting of a control unit, a GPS and a tablet for the monitoring of the speed profile. The results show that the adoption of a lockup clutch allows an increase in the system efficiency during the working phase, hence reducing the average fuel consumption during the mission test.
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D'Août, K., and P. Aerts. "Kinematics and efficiency of steady swimming in adult axolotls (Ambystoma mexicanum)." Journal of Experimental Biology 200, no. 13 (July 1, 1997): 1863–71. http://dx.doi.org/10.1242/jeb.200.13.1863.
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The kinematics of steady swimming at a wide range of velocities was analysed using high-speed video recordings (500 frames s-1) of eight individuals of Ambystoma mexicanum swimming through a tunnel containing stationary water. Animals in the observed size range (0.135­0.238 m total body length) prefer to swim at similar absolute speeds, irrespective of their body size. The swimming mechanism is of the anguilliform type. The measured kinematic variables ­ the speed, length, frequency and amplitude (along the entire body) of the propulsive wave ­ are more similar to those of anguilliform swimming fish than to those of tadpoles, in spite of common morphological features with the latter, such as limbs, external gills and a tapering tail. The swimming speed for a given animal size correlates linearly with the tailbeat frequency (r2=0.71), whereas the wavelength and tail-tip amplitude do not correlate with this variable. The shape of the amplitude profile along the body, however, is very variable between the different swimming bouts, even at similar speeds. It is suggested that, for a given frequency, the amplitude profile along the body is adjusted in a variable way to yield the resulting swimming speed rather than maintaining a fixed-amplitude profile. The swimming efficiency was estimated by calculating two kinematic variables (the stride length and the propeller efficiency) and by applying two hydrodynamic theories, the elongated-body theory and an extension of this theory accounting for the slope at the tail tip. The latter theory was found to be the most appropriate for the axolotl's swimming mode and yields a hydromechanical efficiency of 0.75±0.04 (mean ± s.d.), indicating that Ambystoma mexicanum swims less efficiently than do anuran tadpoles and most fishes. This can be understood given its natural habitat in vegetation at the bottom of lakes, which would favour manoeuvrability and fast escape.
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Shevchenko, Serhii S. "General Approach to Modeling of Non-Contact Seals and Their Effect on the Dynamics of a Centrifugal Machine Rotor." Journal of Mechanical Engineering 25, no. 1 (March 30, 2022): 32–39. http://dx.doi.org/10.15407/pmach2022.01.032.
Full textAbstract:
There is a constant demand for higher equipment parameters, such as pressure of a sealing medium and shaft rotation speed. However, as the parameters rise it becomes more difficult to ensure hermetization efficiency. Moreover, sealing systems affect the overall operational safety of the equipment, especially vibratory. Non-contact seals are considered as hydrostatodynamic supports that can effectively damp rotor oscillations. Models of an impulse and a groove seals, models of rotor-seals system and rotor-auto-unloading system, model of a shaftless pump are studied to evaluate an effect of these sealing systems on oscillatory characteristics of rotor. Analytical dependencies for computation the dynamic characteristics of impulse seals, hydromechanical systems rotor-seals and rotor-auto-unloading, as well as shaftless pumps are obtained. These dependencies describe the radial-angular vibrations of a centrifugal machine rotor in seals-supports. Equations for computation the amplitude-frequency characteristics are given. The directions of improving the оperational safety of critical pumping equipment by purposefully increasing the rigidity of non-contact seals that leads to higher rotor vibration stability have been determined.
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Zdrojewski, Wojciech. "Measuring Stand Tests of a Michell-Banki Waterturbine Prototype, Performedunder Natural Conditions." Transactions on Aerospace Research 2018, no. 2 (June 1, 2018): 77–95. http://dx.doi.org/10.2478/tar-2018-0017.
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Abstract The article presents the result of tests of a single segment of a prototype water turbine, performed in order to determine its shaft power output as a function of rpm, and to verify the declared performance. The results have been compared with the outcomes of numerical calculations performed, for the same conditions, with the use of FLUENT software. The work presents information of crucial importance for presenting the process of testing the piece in question, such as: test environment, properties of the test piece, testing equipment used, as well as the methodology and the course of hydromechanical measurements, along with the characteristics of the results obtained. Then, the measurement results are discussed and analyzed. Conclusions are presented as well. Analysis of the results, taking into consideration the physical image of phenomena occurring in the case of flow-devices, such as water turbines, has made it possible to define other, important characteristics of the turbine, such as: output, shaft torque and efficiency, as a function of rpm and head of turbine. Test results have confirmed the expected mechanical and power-related properties of the turbine and have proved the numerical flow modeling model used effective. A brief description of the prospects concerning new applications of the turbine discussed has been presented as well
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Trukhanov, K. A. "DYNAMICS OF PNEUMATIC DRIVE. LECTURE CYCLE. OPTIMIZATION METHODS FOR SERVO PNEUMATIC DRIVES." Spravochnik. Inzhenernyi zhurnal, no. 303 (June 2022): 1–32. http://dx.doi.org/10.14489/hb.supp.2022.06.pp.001-032.
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The paper considers the main problems of optimal design associated with the choice of optimal parameters that affect both the static and dynamic characteristics of the pneumatic servo drives – control and actuator mechanisms. The possibility of using one decisive criterion (objective function) is shown, which provides the determination of optimal parameters of a pneumatic actuator with forward and rotational movement of the output link, as well as its application in the synthesis of a servo pneumatic cylinder. To calculate the parameters of the servo pneumatic actuator that are close to optimal, a two-criteria LPt-search was applied. It is shown and the corresponding conclusion is made that the proposed objective function can be used in the synthesis of tracking pneumatic/hydraulic drives with forward and rotational motion of the output link. In addition, the objective function for a drive with an energy source is given. The choice of optimal values of the parameters of the digital PID controller to eliminate self-oscillation in systems, as well as optimization of the type of transients of the tracking pneumatic drive is considered. The reason for the study was the problem of the occurrence of self-oscillations in pneumatic systems when using friction models that are closest to real ones. The transition from an analog (continuous) system to a digital (discrete) one is shown and performed, for which it is necessary to determine the sampling period. The paper specifies the main methods for determining the sampling period and shows the disadvantages of these methods. Its described of the criteria definition allowing to choose the optimum parameters of the actuator piston seal. As criteria, it is proposed to use of the actuator’s volume efficiency hо , characterizing the degree of tightness and operating conditions, and hydromechanical hгм efficiency of the actuator, taking into account energy losses due to hydraulic resistance in the channels and friction in it. There are given the calculated dependences for hо and hгм. The scientific novelty of the results presented in the work is that the problem of structural (static) and dynamic optimization of the design of a servo pneumatic device has been solved. A distinctive feature of the above methods for selecting the optimal parameters of a servo pneumatic device is that they are used not at the final stage of development, but at the design stage of a newly developed product, which saves money, time and costs for conducting expensive tests. This work is based and is implemented as a course of lectures of the course “Dynamics of Pneumatic drive”, is red by the author at the Bauman Moscow State Technical University at the Department of “Hydromechanics, Hydraulic Machines and Hydropneumoautomatics” (E10), as part of the preparation of masters in the specialty 05.04.13 – Hydraulic machines and hydropneumatic drives.
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Assadi-Langroudi, Arya, Hassan Abdalla, and Soheil Ghadr. "Fractals for the Sustainable Design of Engineered Particulate Systems." Sustainability 14, no. 12 (June 14, 2022): 7287. http://dx.doi.org/10.3390/su14127287.
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The engineering properties of particulate materials are the collective manifestation of interactions among their constituent particles and are structures within which particles adopt their spatial arrangement. For the first time in the literature, this paper employs an extended concept of ‘fractals’ to show that materials constituting particles of a certain size can be rationalized in three universal fractals. Within each fractal, materials build repeatable, reproducible, and predictable traits, and exhibit the stress-strain behaviors of nondifferentiable, self-similar trajectories. We present experimental evidence for such repeatable traits by subjecting six different particulate materials to static undrained isotropic, static undrained anisotropic, and cyclic undrained isotropic stresses. This paper shows that universal fractals are associated with fractal structures; herein, we explore the matters that influence their spatial arrangement. Within the context of sustainable design, ways of engineering natural particulate systems to improve a product’s physical and hydromechanical properties are already well established. In this review, a novel extended concept of fractals is introduced to inform the biomimetic design of particulate systems, to show how biomimicry can benefit in preserving general behavioral traits, and how biomimicry can offer predicated forms, thereby enhancing the design efficiency. To pursue such an ideal, processes that lead to the engineering of natural materials should not compromise their loyalty to the parent universal fractal.
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Zadorozhnaya, Elena, Vlad Hudyakov, and Sergey Sibiryakov. "Simulation of heat transfer in a turbocharger bearing housing." Tribology and Materials 1, no. 2 (2022): 42–54. http://dx.doi.org/10.46793/tribomat.2022.007.
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Modern world trends in engine building are characterised by the production of forced engines. The most popular and promising forcing method is the use of a turbocharger. The efficiency of journal bearings determines the reliability of TCR, which should be structurally simple, compact, reliable and inexpensive, while providing acceptable characteristics of rotor dynamics, noise, vibration and stiffness speeds. The best performance of the bearing unit is achieved with hydrodynamic lubrication, which depends on optimal operating and temperature conditions. The maximum operating temperature of the bearing assembly must be taken into account at the design stage. The purpose of this article is to develop an algorithm for calculating the heat transfer in the turbocharger bearing housing in order to assess the effect of the thermal state of the radial bearing on its performance and on the dynamics of the rotor. The simulation was carried out in the ANSYS software package and the developed software. The boundary conditions for the calculation were obtained from experimental data. The result of the simulation was the determination of temperatures and thermal fields in the turbocharger housing, as well as the values of the change in clearances under the influence of thermal expansion of parts. Verification of the results was carried out on the basis of comparison with the results obtained by other authors. Conclusions were drawn about the effect of thermal deformations on the rotor dynamics and the hydromechanical characteristics of the bearing.
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KRASNEVSKIY, Leonid G. "AUTOMATIC TRANSMISSIONS: ON THE RELATIONSHIP BETWEEN THE CAVITATION MODES OF THE TORQUE CONVERTER AND HIGH-FREQUENCY RESONANT TORSIONAL OSCILLATIONS OF MECHANICAL COMPONENTS." Mechanics of Machines, Mechanisms and Materials 4, no. 61 (December 2022): 5–18. http://dx.doi.org/10.46864/1995-0470-2022-4-61-5-18.
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Based on the analysis of foreign publications, a number of new scientific results are presented in the field of hydrodynamics of working fluid flows in torque converters (TC) of automatic hydromechanical transmissions (AHMT), including cavitation in TC, which were obtained using the new CFD (Computational Fluid Dynamics) technology as part of research to reduce the vibroacoustic loading of AHMT. CFD modelling methods have shown that cavitation in a TC, along with the creation of noise and vibration, significantly degrades its characteristics (in the example given, the transformation coefficient is by 18.1 %, efficiency is by 5.8 %, turbine torque is by 20.3 %), and also creates high-frequency oscillations in a wide range that can resonate with the natural frequencies of the AHMT components. The influence of structural and operational factors on cavitation is investigated. The greatest cavitation occurs on the blades of the TC stator in stop mode when the car accelerates from a standstill. The results of CFD modelling are in good agreement with experimental data. CFD technology has become an effective tool for optimizing the design of an automotive TC, its blade system, flow part, visualization of internal flows, study of the mechanism of occurrence and impact of cavitation. The analysis of methods of attenuation of cavitation is carried out, including the selection and maintenance of the value of the TC recharge pressure. The presented provisions in Russian are published for the first time.
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Evin, Emil, and Miroslav Tomáš. "Formability Prediction of Laser-Welded Stainless Steel AISI 304 and AISI 430." Metals 12, no. 1 (December 27, 2021): 54. http://dx.doi.org/10.3390/met12010054.
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The effect of laser welding on the mechanical properties and the prediction of formability for austenitic stainless steel AISI 304 and ferritic steel AISI 430 when welded by a YLS-5000 fiber laser, were studied in the paper. The microstructure of the welded joint was analyzed using light microscopy. The mechanical properties were determined by static tensile testing. The forming limit diagrams were produced from notched samples at R5, R17, and R25 mm. The hardness values of the welded joint and the base material were determined using the Vickers method. Samples made of AISI 430 showed that the formability suffered due to laser welding. Longitudinal coarse ferrite grains were observed in the microstructure of the AISI 430 weld metal. The coarse-grained structure of the welded joint and the continuous interface along the centerline caused the failure of the AISI 430 laser-welded samples at significantly lower actual stress and strain values than were required to break the base material. No significant changes in the formability were observed in the AISI 304 samples after laser welding. The growth of dendrites was observed in the microstructure of the AISI 304 welded joint in a direction towards the centerline of the welded joint. A comparison of the experimentally determined FLD0 values and the values calculated from predictive equations showed that a better agreement was achieved for uniform elongation than for the strain hardening exponent. The manufacturability and economic efficiency of selected parts of an exhaust system by hydromechanical drawing were evaluated on the basis of the process capability index Cpk.
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Droździel, Paweł, Tetiana Vitenko, Viktor Voroshchuk, Sergiy Narizhnyy, and Olha Snizhko. "Discrete-Impulse Energy Supply in Milk and Dairy Product Processing." Materials 14, no. 15 (July 27, 2021): 4181. http://dx.doi.org/10.3390/ma14154181.
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The efficient use of supplied energy is the basis of the discrete-impulse energy supply (DIES) concept. In order to explore the possibility of using DIES to intensify the hydromechanical processes, the emulsification of milk fat (homogenization of milk, preparation of spreads) and, in particular, the processing of cream cheese masses, were studied. Whole non-homogenized milk, fat emulsions, and cream cheese mass were the object of investigation. To evaluate the efficiency of milk homogenization, the homogenization coefficient change was studied, which was determined by using the centrifugation method, as it is the most affordable and accurate one. To provide the proper dispersion of the milk emulsion, six treatment cycles must be carried out under the developed cavitation mode in a static-type apparatus, here resulting in a light grain-like consistency, and exhibiting the smell of pasteurized milk. The emulsions were evaluated according to the degree of destabilization, resistance and dispersion of the fat phase. On the basis of the obtained data with respect to the regularities of fat dispersion forming in the rotor-type apparatus, the proper parameters required to obtain technologically stable fat emulsion spreads, possessing a dispersion and stability similar to those of plain milk creams, were determined. It was determined that under the DIES, an active dynamic effect on the milk globules takes place. The rheological characteristics of cheese masses were evaluated on the basis of the effective change in viscosity. The effect of the mechanical treatment on the structure of the cheese masses was determined.
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Krasovskyi, H. Ya, V. O. Shumeiko, T. O. Klochko, and N. I. Sementsova. "INFORMATION TECHNOLOGIES FOR MONITORING THE ENVIRONMENTAL CONSEQUENCES OF AMBER PRODUCTION IN UKRAINE." Ecological Safety and Balanced Use of Resources, no. 2(18) (June 15, 2018): 107–17. http://dx.doi.org/10.31471/2415-3184-2018-2(18)-107-117.
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Among the environmental consequences of the illegal production of amber, the experts single out the degradation of zonal soils and underlying bed rocks, destruction of fertile humus and eluvial horizons of podzolic soils, root systems of trees, swamp formation, change in groundwater levels, destruction of forest resources, and change in the migration processes of the region’s fauna. The most serious ecological and economic problems are caused by the unauthorized production of amber in Rivne, Volyn and Zhytomyr oblasts, where the illegal production of amber is carried out by open-pit and hydromechanical methods.
The main tasks set forth in the article are: to analyze the places and conditions of amber production, to define its influence on the environment components, to identify the objects of natural resources use by means of Earth remote sensing methods.
The article deals with the development of modern information technology for identifying the places and consequences of amber production in the western regions of Polissia based on the methods of satellite environmental monitoring and tools of geoinformation systems. The production technologies and the manifestation of their ecological impacts are described. The environmental impact assessment of amber production is not possible without defining the potential operational risks, identifying the locations and extent of environmental damage. Due to local peculiarities of amber production management, it is rather difficult to fix the topographic and geodetic parameters of the manifestations of these effects, which complicates the planning of prevention and elimination measures. The methods of Earth remote sensing (ERS) from space and geoinformation systems (GIS) can define these parameters with high accuracy, reliability and efficiency, which will enable the efficient monitoring of the environmental components degradation.
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Mikhailova, O. V., M. V. Belova, A. N. Korobkov, and G. V. Novikova. "Development of a plant for peeling rapeseed in the electromagnetic field of ultrahigh frequency." Proceedings of the Voronezh State University of Engineering Technologies 81, no. 2 (November 1, 2019): 27–34. http://dx.doi.org/10.20914/2310-1202-2019-2-27-34.
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Currently, domestic industry uses imported raw materials. At the same time, supplies of rapeseed oil for export as raw materials account for about 80% of the production volumes. Therefore, import substitution of rapeseed oil due to an increase in its own production and a significant increase in the efficiency of processing technology with improved quality characteristics, the development of innovative technology and technical means to improve the quality of peeling of rapeseed is relevant. Depending on the grain structure, one of three methods of peeling is used: compression and shear, multiple or single blow, by abrasion of the shells. The rapeseed kernel has a fragile structure, so peeling with a multiple blow is irrational. Two requirements are imposed on the rape seed peeling process: high-quality separation of husk from the kernel and preservation of the integrity of the kernel. The article describes the developed design of the installation for peeling rape in an electromagnetic field, which allows the peeling process to be carried out at low operating costs. The process of peeling rape is possible by hydromechanical destruction and abrasion of husks on rotating abrasive disks and mutual friction of grains in the EMF microwave, followed by removal of the shells by blowing air through a hollow dielectric shaft with holes and a perforated cylindrical resonator. The article also describes the technological process of rape peeling and conducted a feasibility study on the implementation of the proposed installation. The economic effect of the use of a microwave installation for rape peeling is 124 thousand rubles/month with the volume of output 38.5 tons/month, profitability will increase by 3.7%.
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Orlov, O. "Prediction of propeller hydromechanics for a single-shafter." Transactions of the Krylov State Research Centre 1, no. 395 (March 9, 2021): 65–78. http://dx.doi.org/10.24937/2542-2324-2021-1-395-65-78.
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Object and purpose of research. This paper discusses hydromechanics properties of propeller and their scaling laws. The purpose of this study was to analyse existing methods of scaling model test data through their comparison with full-scale test results, identify possible sources of considerable error that might be present in them, as well as update the method of model test data scaling taking into account hydrodmechanic interaction between propeller and hull in terms of their model data extrapolation to the full scale. Materials and methods. The paper discusses general relationships between hydromechanic parameters of hull and propeller, that arise, in their turn, from the fundamental laws of mechanics. These relationships were used to analyse interconnected laws governing the full-scale extrapolation of model test data for hull resistance, propeller thrust and propeller torque. Main results. The study identified some incorrect hypotheses in current scaling methods for hydrodynamics of propeller in behind-hull conditions, that might bring about considerable error in full-scale estimates of operational advance coefficient, thrust coefficient, efficiency and RPM. Conclusion. This paper suggests alternative techniques for determination of operational advance coefficient and other hydromechanics parameters of full-scale propeller, so as to obtain the estimates that take into account physical peculiarities of scale effect and also correlate with the results of full-scale trials.
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Kisel', YU E., S. P. Simokhin, and S. A. Murachev. "Intensification of the recovery of hydraulic equipment parts by iron in the electrolyte flow." Traktory i sel hozmashiny 88, no. 4 (August 15, 2021): 63–70. http://dx.doi.org/10.31992/0321-4443-2021-4-63-70.
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The technology of bath-free ironing of parts in an electrolyte flow with simultaneous hydromechanical activation of the growing surface is proposed. Its advantages over the traditional type of coating are introduced. The structure, some physicomechanical and operational properties of iron coatings were studied depending on the electrolysis regimes and the composition of electrolytes. The possibility of high-speed electrodeposition of iron with a wide range of physical and mechanical properties is shown. There were shown the electrolysis modes, which make it possible to obtain high-quality strong-adhered pure-iron coatings with a wear resistance several times higher than hardened alloy steels and a precipitation growth rate tens of times higher than with traditional ironing. A typical technological process of parts ironing was developed. It was tested on the example of restoration of hydraulic valve spools of agricultural machinery. The design of an installation and an electrochemical cell for ironing the valve hydraulic distributors, providing optimal hydrodynamic conditions when applying coatings to worn surfaces, was proposed. Recommendations for the post-electrolysis treatment of restored parts by iron are given. Bench and field tests of hydraulic valves with remanufactured valves were carried out. They confirmed the results of laboratory studies, and showed that no malfunctions were identified during the operation period. Technical and economic calculations have shown the high efficiency of the proposed technology in comparison with traditional ironing. The introduction of the technology in production will reduce the production area and the time spent on restoring parts by increasing the productivity of the iron process and reducing the number of operations, reducing the cost of materials for preparing electrolytes by reducing the operation of anodic treatment and washing, and increasing the reliability of the technology by improving its structural scheme.
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Grachev, Vladimir, Aleksandr Grischenko, Fedor Bazilevskiy, and Maksim Panchenko. "Method for Equalization of Cylinder Powers of Multi-Cylinder Locomotive Diesel." Bulletin of scientific research results 2022, no. 3 (September 22, 2022): 103–17. http://dx.doi.org/10.20295/2223-9987-2022-3-103-117.
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Purpose: Labor intensity reduction and equalization accuracy improvement of cylinder powers of a multi-cylinder diesel locomotive on account of application as a diagnostic parameter, characterizing cylinder power unevenness, — the energy of low-frequency band of spectrum for crankshaft instantaneous angular velocity (CIAV) signal. Methods: Methods of mathematical modeling of diesel crankshaft instantaneous angular velocity, mathematical modeling of diesel engine working process, digital signal processing, spectral analysis, differential calculus and multidimensional non-differentiable function optimization are used in the work. Results: Method for equalization of cylinder powers of a multi-cylinder diesel locomotive that’s based on a continuous monitoring of the spectrum of crankshaft instantaneous angular velocity signal is proposed and justified. Energy of low-frequency band of the signal spectrum of CIAV can be used as a diagnostic parameter, characterizing cylinder load unevenness. The parameter value minimization by means of sequential correction of cyclic fuel supply and fuel advance angle ensures the decrease in the pointed unevenness. Practical importance: The proposed method can be used when adjusting fuel equipment after the repair of a diesel engine as with electronic fuel supply control systems as well as with hydromechanical fuel equipment. The use of the given method excludes the necessity of temperature measurement for exhaust gases and flash pressure measurement in cylinders for fuel equipment adjustment that’s especially important for high-speed diesel engines which cylinder heads’ construction doesn’t provide for indicator cocks. In the engines equipped with electronic fuel control systems, the use of IAV signal spectrum low-frequency band energy as a diagnostic parameter makes it possible to automate fully the equalization process for cylinder load. The result of the proposed method application will be the reduction in the duration and labor intensity of diesel locomotives rheostat tests as well as the rise in diesel locomotives reliability and efficiency at the expense of uniform loading of diesel cylinders.
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Mukatova, M. D., N. A. Kirichko, M. S. Moiseenko, and S. A. Skolkov. "DEVELOPMENT OF TECHNOLOGY FOR OIL EXTRACTION FROM FAT-CONTAINING WASTES OF FISH PROCESSING IN THE VOLGA-CASPIAN BASIN." Izvestiya TINRO 193 (July 9, 2018): 211–22. http://dx.doi.org/10.26428/1606-9919-2018-193-.
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Complete utilization of all wastes of fish processing becomes actual in modern conditions of depletion of the fish raw materials because of the commercial catch decreasing in the Volga-Caspian Basin. Abilities of fish oil extraction from fins of catfish are considered. Several technologies of the oil extraction from this waste are tested: thermal, carbamide-thermal, combined carbamide-thermal, and hydromechanical. Organoleptic parameters of the raw materials and produced fatty products are determined in accordance with the state standard № 7631-2008. Water, protein, fat, and mineral substances content in the raw material and physical and chemical properties of the produced fish oil are measured by standard methods given in the state standard № 7636-85, using the thin-layer chromatography. The fat content in the raw material is evaluated as 33.8 %. The fish oil output from the fat-containing raw materials is determined. The carbamide-thermal method is defined as the optimal one for oil extraction from fins of catfish. At the first stage, the raw material is heated to 70 о C during 60 minutes, then it is mixed with 1.5 % of carbamide in 30 % solution and the liquid and dense fractions of the mixture are separated under 3000 rpm in 30 minutes; at the second stage, the dense fraction is heated to 70°C, mixed with 20 % of water, and the mixture is heated to 75 о C during 60 min, then the liquid and dense fractions of the mixture are separated again; finally, the liquid fractions from both stages of treatment are subjected to sedimentation during 10 minutes under ambient temperature and the semi-finished fatty products are separated by 15 min. centrifuging at 4000 rpm. Phospholipids, monoglycerides, sterols, hydrocarbons, sterol esters, and the main fractions of triglycerides and carotenoids are presented in the fish oil produced with this technology, so it could be used in veterinary. This method for fish oil extraction from the fins of catfish is applied to the enterprises Parshikov and Fabrika Vesna and showed its efficiency in industrial conditions.
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Pylypenko, O. V. "Solving current problems in engineering system dynamics." Technical mechanics 2021, no. 2 (June 29, 2021): 3–19. http://dx.doi.org/10.15407/itm2021.02.003.
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This paper overviews the main results obtained over the past few years at the Department of Hydromechanical Systems Dynamics and Vibration Protection Systems, Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, in the solution of current problems in the dynamics of liquid-propellant rocket engines (LPREs), liquid-propellant launch vehicle pogo stability, vibration protection system dynamics, the gas dynamics of aircraft gas turbine engine components, and the dynamics of hydraulic systems with cavitating elements. These results are as follows. A mathematical model of LPRE pump dynamics was developed. The model complements a hydrodynamic model of LPRE cavitating pumps by allowing a mathematical simulation of choking regimes. An approach was developed to the construction of a nonlinear mathematical model of LPRE hydraulic line filling. The approach allows one to automatically change, if necessary, the finite element partitioning scheme of a hydraulic line in the process of its filling during LPRE startup calculations. An investigation was conducted into the startup dynamics of a multiengine liquid-propellant propulsion system that consists of four staged-combustion oxidizer-rich LPRDs with account for the possibility of their nonsimultaneous startup. The maximum values of oxidizer and fuel pressure surges and undershoots at the liquid-propellant jet system (LPJS) inlet at an engine spartup and shutdown were determined and used in determining the LPJS operability at the startup and shutdown of the RD861K sustainer engine. The pogo stability of the Cyclone-4M launch vehicle was analyzed analytically using Nyquist’s criterion. A numerical approach was developed to characterizing acoustic oscillations of the combustion products in annular rocket combustion chambers with account for the configuration features of the fire space and the variation of the physical properties of the gaseous medium with the axial length of the chamber. A prototype vibration protection system was developed and made, and its dynamic tests confirmed its high efficiency in damping impact and harmonic disturbances. Approaches were developed to the aerodynamic improvement of aircraft gas turbine engine components. Topical problems in solids grinding in a liquid medium with the use a cavitation pulse technology were solved.
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Nauen, Jennifer C., and George V. Lauder. "Quantification of the wake of rainbow trout (Oncorhynchus mykiss) using three-dimensional stereoscopic digital particle image velocimetry." Journal of Experimental Biology 205, no. 21 (November 1, 2002): 3271–79. http://dx.doi.org/10.1242/jeb.205.21.3271.
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SUMMARYAlthough considerable progress has been made within the last decade in experimental hydrodynamic analyses of aquatic locomotion using two-dimensional digital particle image velocimetry (two-dimensional DPIV), data have been limited to simultaneous calculation of two out of the three flow velocity variables: downstream (U), vertical (V) and lateral(W). Here, we present the first biological application of stereo-DPIV, an engineering technique that allows simultaneous calculation of U, V and W velocity vectors. We quantified the wakes of rainbow trout (Oncorhynchus mykiss, 16.5-21.5 cm total body length, BL), swimming steadily in a recirculating flow tank at a slow cruising speed of 1.2 BL s-1. These data extend the comparative basis of current hydromechanical data on the wakes of free-swimming fishes to the salmoniforms and are used to test current hypotheses of fin function by calculations of mechanical performance and Froude efficiency.Stereo-DPIV wake images showed three-dimensional views of oscillating jet flows high in velocity relative to free-stream values. These jet flows are consistent with the central momentum jet flows through the cores of shed vortex rings that have been previously viewed for caudal fin swimmers using two-dimensional DPIV. The magnitude and direction of U, V and W flows in these jets were determined over a time series of 6-8 consecutive strokes by each of four fish.Although the fish swam at the same relative speed, the absolute magnitudes of U, V and W were dependent on individual because of body size variation. Vertical flows were small in magnitude (<1 cm s-1) and variable in direction, indicating limited and variable vertical force production during slow, steady, forward swimming. Thus, in contrast to previous data from sunfish (Lepomis macrochirus) and mackerel (Scomber japonicus), the trout homocercal caudal fin does not appear to generate consistent vertical forces during steady swimming. U flows were of the order of 3-6 cm s-1; lateral flows were typically strongest, with W magnitudes of 4-6 cm s-1. Such strong lateral flows have also been shown for more derived euteleosts with homocercal caudal fins.The ratios of the magnitudes of wake flow, U/(U+V+W), which is a flow equivalent to mechanical performance, were also dependent on individual and ranged from 0.32 to 0.45, a range similar to the range of mechanical performance values previously determined using standard two-dimensional DPIV methods for caudal fin locomotion by more derived euteleosts. Strong lateral jet flow appears to be a general feature of caudal fin locomotion by teleosts and may reflect the nature of undulatory propulsion as a posteriorly propagated wave of bending. Froude efficiency (ηp) was independent of individual; meanη p was 0.74, which is similar to previous findings for trout.
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M Ya, Khabibullin. "Improvement of disc stack centrifuge design to increase efficiency of formation fluid separation." Journal of Physics: Conference Series 2176, no. 1 (June 1, 2022): 012008. http://dx.doi.org/10.1088/1742-6596/2176/1/012008.
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Abstract It should be noted that numerous theoretical studies on flow hydromechanics in the centrifugal field have not been sufficiently used in designing separators with a high productivity index. This is caused by the extreme complexity of the flow conditions of the separated liquid in the intrarotor space. Therefore, experimental studies of intra-rotor flows have now gained great importance. The obtained results of studies carried out on a real product at a pressure and flow rate corresponding to production conditions made it possible to create and manufacture an industrial sample of the assembly. The authors use experimental data to calculate similar hydrocyclones ment for operation with other mixtures.
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Vaz, Álvaro, António Espírito-Santo, Pedro Araújo, Rogério Simões, and Jacques Silvy. "Energy efficiency in low consistency refining: a study using a Valley beater." Nordic Pulp & Paper Research Journal 34, no. 1 (March 26, 2019): 67–74. http://dx.doi.org/10.1515/npprj-2018-0009.
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Abstract The purpose of this work was to study the influence of pulp fiber suspensions refining operating variables on energy efficiency coefficient. Three chemical pulps with different average morphological characteristics were used, obtained from bleached kraft Pinus sylvestris, Eucalyptus globulus and Betula verrucosa. The final objective was to establish the chemical pulps refining efficiency parameters. Refining hydromechanics and energy consumption profiles were analyzed. Average normal and tangential forces on pulp suspension in the gap clearance, resulting rotor-stator distance and no-load and refining conditions power consumption were obtained. The refining trials took place in a laboratory Valley beater, and the manipulated variables were charge on the roll and rotor rotation speed. Global relationships for tangential stress and energy efficiencies in terms of rotation speed and rotor-stator gap were obtained. A relationship between energy efficiency and shear stress was obtained. The results have shown that in a Valley beater increased rotor-stator gaps reduce energy efficiency, concomitantly increasing apparent viscosity and reducing shear stress. No-load power was seen to increase with crowding factor, and thus with flocculation. Inversely, crowding factor and ultimately flocculation had an adverse effect on energy efficiency.
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Zhao, Xue Song, Jian Hu, and Pei Cheng Shi. "Hydromechanics Research of Pump Flow Control System Based on BP Neural Network PID." Applied Mechanics and Materials 327 (June 2013): 222–26. http://dx.doi.org/10.4028/www.scientific.net/amm.327.222.
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In order to improve the accuracy of the pump flow control system,With the application of hydromechanics:the actual flow of the pump is restricted by head,the mathematical model of the fluid flow control system is established.Through the analysis, which obtained three kinds of unit step response curve of the pump flow control when it is under the condition that without using the PID,using the PID and using the BP neural network combined with the PID control. It is concluded that the efficiency of using the BP neural network combined with the PID is much better, Which can improve the pump flow control system's accuracy.