Artículos de revistas: "Compressed air cannon"

1

Taylor, Brett. "Recoil Experiments Using a Compressed Air Cannon". Physics Teacher 44, n.º 9 (diciembre de 2006): 582–84. http://dx.doi.org/10.1119/1.2396775.

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2

Rohrbach, Z. J., T. R. Buresh y M. J. Madsen. "Modeling the exit velocity of a compressed air cannon". American Journal of Physics 80, n.º 1 (enero de 2012): 24–26. http://dx.doi.org/10.1119/1.3644253.

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3

Duan, Zhengyong, Tianhong Luo y Dayong Tang. "Potential Analysis of High-g Shock Experiment Technology for Heavy Specimens Based on Air Cannon". Shock and Vibration 2020 (26 de noviembre de 2020): 1–8. http://dx.doi.org/10.1155/2020/5439785.

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According to the technical requirements of harsh shock environment test, this paper presents the study on the pneumatic vertical test technology with large load and high-g value. The inspiration of this paper comes from the fact that a compressed air cannon can produce instantaneous and powerful air jets that can be used to drive the tested object to achieve a high initial collision velocity. Then, the principle of shock test technology based on an air cannon and an impact cylinder was put forward, and the idea gas mechanics model was established to theoretically analyze the laws that how the parameters of the air cannon and cylinder influence the initial impact velocities. The test system was built, and the test research was carried out. When the air cannon pressure is 0.5 MPa and 0.65 MPa, respectively, under no-load, the impact acceleration measured is 1990 g (pulse width, 1.26 ms) (1g = 9.8 m/s2) and 4429 g (pulse width, 1.20 ms). It preliminarily validated the effectiveness and feasibility.

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4

Capanna, R. y P. M. Bardet. "High Speed PIV and Shadowgraphy Measurements in Water Hammer". Proceedings of the International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics 20 (11 de julio de 2022): 1–10. http://dx.doi.org/10.55037/lxlaser.20th.170.

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An experimental study addressing the challenge to measure relaxation coefficient of very fast phenomena such as water hammers is presented. A titanium projectile containing a sapphire tube containing water is accelerated and impacts a metal wall creating a water hammer. A compressed air custom built cannon is used to accelerate the projectile and create the impact leading to the water hammer. The sapphire tube, being transparent to green and UV light allows the deployment of non intrusive laser based diagnostic techniques such as Particle Image Velocimetry, Shadowgraphy, and Fiber Optic Hydrophone pressure measurements. These laser based techniques will be deployed at a very high repetition rate (>100 kHZ) to measure the relaxation coefficients between gas and water phase. First experimental results for Shadowgraphy and PIV measurements are presented. The propagation speed of shock wave in the projectile has been estimated from shadowgraphy measurements and matched the theoretical calculation. Discussion on the future development for the presented facility concludes this paper.

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5

Yang, Xiaoguang, Jianjun Dang, Peng Wang, Yadong Wang, Yingjun Han, Cheng Chen y Deying Li. "Experimental research on influence of wave environment on high-speed water entry load and trajectory characteristics". Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 39, n.º 6 (diciembre de 2021): 1259–65. http://dx.doi.org/10.1051/jnwpu/20213961259.

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Wave environment is a common fact happened when objects enter water under real conditions, which changes the morphology of the free interface when entering water. However, the influence of wave environment on the flow when entering water and on the evolution of object motion parameters after entering water is not clear. In this research, a rocking plate wave maker is used to generate a wave environment in the test pool, and a truncated cone rotating body equipped with an internal test system is used as the test model. The compressed air cannon is used to provide launch power, and the launch control system uniformly controls the start timing process of the wave maker and the launcher. The wave maker and the launcher will control the relative position of the object's entry point and the wave surface in collaboration. Various condition tests were carried out, including enter in static water, different wave surface positions and different wave heights. Quantitative trajectory parameters including the acceleration, and attitude angle of the model in the water-entry process were obtained, and the evolution of the flow field was photographed. The experimental results show that under high-speed conditions, the influence of waves on the water-entry process is mainly reflected in the change of the water entry angle relative to the water surface at the water-entry moment. The wave surface encountering negative inclination can effectively reduce the impact load of water entry, but it is more likely to induce the extreme situation such as "jumping".

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6

Madavha, Muster Thivhileli y Mohamed-Tariq Kahn. "Design and Analysis of a Micro-Hydro Distributed Power System". International Journal of Engineering Research in Electrical and Electronics Engineering 9, n.º 9 (13 de septiembre de 2022): 1–7. http://dx.doi.org/10.36647/ijereee/09.09.a001.

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The purpose of this study is to improve the standard way of producing electricity in a hydropower plant through the introduction of a more effective method. The aim of installing this Micro-hydro Distributed Power System is to achieve greater results in comparison to those attained with a standard micro-hydro power plant, without depending upon rainfall but upon two stored natural resources, air and water. This air supply will come from solar compressors and the water will be drawn from existing dams or runoff from rivers into storage tanks, which will generate electricity throughout the year at the same rate as the existing micro-hydropower that depends upon rainfall. The Micro-hydro Distributed Power System is a working pressure hydropower plant that generates electricity by compressing fluid into the system, using compressed air and is designed and analyzed in CAD design software and results are calculated to ensure the design is sufficiently durable to withstand the pressure, since the entire power system is dependent upon working pressure and how the power is generated using two major renewable sources, water and air. The Micro-hydro Distributed Power System’s working principle has been adapted from hydropower plants, the system converts H-Head(m) into pressure which is then used in the formula in (P=ρgh) to determine the power of the system. Theoretically, the findings of this study prove that the power to be generated, based upon the calculations, is much higher than expected before commencing the research, the power input needed for the Micro-hydro Distributed Power System based upon the compressor system’s rated power is 11KW to produce the 13 bars of pressure needed to compress fluid for maximum power output. At 13 bars the compressor system is found to be producing 398.3MW of power but at a high rate of flow of water which is found to be 391.907 L/s. A major advantage of the Micro-hydro Distributed Power System is that this water is pumped back into the tank from which it is re-used over and over again. This system depends entirely upon compressed air which is used to compress fluid through pipes, without this compressed air the water does not flow and cannot be pumped back into the system

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7

Dobrotvorskiy, Sergey, Ludmila Dobrovolska, Yevheniia Basova y Borys Aleksenko. "PARTICULARS OF ADSORBENT REGENERATION WITH THE USE OF MICROWAVE ENERGY". Acta Polytechnica 59, n.º 1 (28 de febrero de 2019): 12–23. http://dx.doi.org/10.14311/ap.2019.59.0012.

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Energy conservation issues are acute in the world. Compressed air is widely used in the modern industrial production. The production of compressed air is a very energy-intensive process, since most of the energy, which is expended by the compressor, passes into the energy of heating. Compressed air cannot be used in modern production without a prior drying and cleaning. Industrial dryer’s air losses is up to 20% of compressed air additionally. Therefore, the issue of saving air during its drying stage is important. In the presented article, the thermal and aerodynamic processes that occur in the classical adsorption tower with the most modern design are considered. The processes that occur in the adsorption column with the microwave regeneration of the adsorbent are also considered. A comparative analysis of these constructions from the point of view of energy saving is made.

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8

Ren, Xu, Cai, Wang y Li. "Experiments on Air Compression with an Isothermal Piston for Energy Storage". Energies 12, n.º 19 (29 de septiembre de 2019): 3730. http://dx.doi.org/10.3390/en12193730.

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Air is usually compressed adiabatically in the compressor. As the operating speed of compressors can be several thousand rpm, heat generated during compression cannot be sufficiently transmitted to the environment in such a short time. It is for this reason that compressor efficiency is limited. Isothermal compression could be an alternative choice applied on industrial compressor and compressed air energy storage (CAES). This paper proposed a new kind of piston to perform isothermal compression. Surface area of such isothermal piston structure is larger. A certain amount of fluid at the chamber bottom absorbs the heat from the isothermal piston. Heat transfer between piston and fluid during compression is investigated. Air pressure is measured to validate the effectiveness of this proposed piston structure in heat transfer. Compression work of the proposed isothermal piston and conventional one is compared. One issue of this comparison is that air-liquid dissolution can affect the pressure and compression work. The influence of dissolution is quantified with Henry’s Law. Quantitative analysis is performed to determine that heat transfer is the dominant factor affecting the pressure and compression work. Some simple experiments are described in this paper, which shed light on that heat transfer could be significantly improved adopting this proposed isothermal piston.

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9

Naufal Annafi, Muhammad, Asman Ala y Jarot Delta Susanto. "Optimizing Air Compressor Productivity in Supporting Operational Activities on The Mt Ship. Gamalam". International Journal of Advanced Multidisciplinary 2, n.º 2 (14 de septiembre de 2023): 608–11. http://dx.doi.org/10.38035/ijam.v2i2.304.

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Air compressors are auxiliary machines on board that can produce high pressure air. This research was conducted because the productivity of the air compressor was less than optimal, causing air production and the performance of the air compressor to be less than optimal and disrupting operational activities on the ship. The impact that occurs when air production is reduced in the air compressor, the ship cannot operate according to the contract specified by the company, because the initial start of the main engine or main engine on board requires compressed air. Many factors can cause reduced production of air produced by air compressors, including the lack of performance of the suction valve and exhaust valve on the high pressure section which causes less maximum or longer time for filling air into the air bottle, low flow of the lubrication system on the piston which causes no compression to produce air. This research was carried out with the aim of identifying and analyzing the causes of the lack of performance of the suction and exhaust valves on high pressure sections and low flow of the piston lubrication system which results in less optimal performance of the air compressor when filling into air bottles. The method used in this study uses a qualitative descriptive method using primary and secondary data collection approaches and techniques. The lack of performance of the inlet and exhaust valves can be corrected by cleaning the carbon deposits on the valves and leveling the valve surfaces. The low flow of the lubrication system on the piston can be done by checking the lubricating oil pump, cleaning the lubricating oil filter, changing the lubricating oil periodically according to the instruction manual book, and adding lubricating oil according to the specifications of the air compressor.

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10

Dierolf, Christian y Alexander Sauer. "Automatisierte KI-basierte Leckage-Erkennung/Automated AI-based leak detection". wt Werkstattstechnik online 111, n.º 03 (2021): 152–58. http://dx.doi.org/10.37544/1436-4980-2021-03-60.

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Obwohl Druckluftleckagen jährlich hohe Kosten verursachen, ist deren automatisierte und aufwandsarme Erkennung immer noch nicht möglich. In diesem Beitrag wird das Konzept einer automatisierten KI-basierten Leckage-Erkennung vorgestellt und auf einen Druckluft-Labordemonstrator angewendet. Erste Validierungen der Vorgehensweise zeigen, welche Potenziale und Herausforderungen sich für das Leckage-Management an Druckluftmaschinen ergeben.   Though incurring substantial costs every year, compressed air leakages still cannot be detected automatically and without much effort. This paper presents a method for an automated AI-based leak detection system, which is applied to a compressed air laboratory demonstrator. First validations of the approach show what potential and challenges there are in the leakage management of compressed air machines.

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11

Cheayb, Mohamad, Sébastien Poncet, Mylène Marin-Gallego y Mohand Tazerout. "Parametric Optimisation of a Trigenerative Small Scale Compressed Air Energy Storage System". Proceedings 23, n.º 1 (23 de agosto de 2019): 5. http://dx.doi.org/10.3390/proceedings2019023005.

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Recently, major improvement on compressed air energy storage technology has been made by using the heat of compression for heating energy or using it to preheat the compressed air in the expansion phase and by demonstrating its ability to produce cooling energy. Thus, the trigenerative compressed air energy storage has been introduced. In this paper, we introduce a configuration of trigenerative compressed air energy storage system giving the preference to the electric energy production. The study then focuses on undertaking an optimization study via a parametric analysis considering the mutual effects of parameters. This analysis is applied to a micro-scale application including the existing technological aspects. The parametric study results applied on the hot temperature of the thermal energy storage indicate the possibility to find an optimal solution as a trade-off between system performances and other parameters reflecting its cost. On the contrary, the selection of the maximal storage pressure cannot be achieved by finding a compromise between energy density and system efficiency. A complete study of other design parameters will be addressed in a future publication.

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12

Mo, J. P. T. "Analysis of Compressed Air Flow Through a Spool Valve". Proceedings of the Institution of Mechanical Engineers, Part C: Mechanical Engineering Science 203, n.º 2 (marzo de 1989): 121–31. http://dx.doi.org/10.1243/pime_proc_1989_203_095_02.

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A pneumatic servo-mechanism with a sophisticated control algorithm based on variable closed-loop gains has been developed recently on specially designed pneumatic drives. Unfortunately, due to the compressibility of air, models derived using traditional linearization methods could not describe the behaviour of the system over its full stroke and hence prevented the generalization of the control algorithm on a commercial platform. The problem is tackled by the component-oriented approach which segregates the pneumatic servo-mechanism into individual components for more precise analysis. This paper describes the analysis of one of the components—a five-port spool valve from the concept of a flow node in the valve land. The new valve model, which incorporates an extension to include an upstream flow head in the one-dimensional adiabatic flow equation, can predict the mass flowrates at all spool displacements satisfactorily. The flow node model can also be used to derive the theoretical pressure variations due to leakage which cannot be deduced in the conventional approach.

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13

Jia, Guanwei, Xuanwei Nian, Weiqing Xu, Yan Shi y Maolin Cai. "Water-Spray-Cooled Quasi-Isothermal Compression Method: Water-Spray Flow Improvement". Entropy 23, n.º 6 (6 de junio de 2021): 724. http://dx.doi.org/10.3390/e23060724.

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Water-spray-cooled quasi-isothermal compressed air energy storage aims to avoid heat energy losses from advanced adiabatic compressed-air energy storage (AA-CAES). The compression efficiency increases with injection water spray. However, the energy-generated water spray cannot be ignored. As the air pressure increases, the work done by the piston and the work converted into heat rise gradually in the compression process. Accordingly, the flow rate of the water needed for heat transfer is not a constant with respect to time. To match the rising compression heat, a time sequence of water-spray flow rate is constructed, and the algorithm is designed. Real-time water-spray flow rate is calculated according to the difference between the compression power and heat-transfer power. Compared with the uniform flow rate of water spray, energy consumption from the improved flow rate is reduced.

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14

Kurkus-Gruszecka, Michalina, Piotr Krawczyk y Piotr Łapka. "CFD modelling and validation of the rotary lobe compressed air expander". MATEC Web of Conferences 240 (2018): 05015. http://dx.doi.org/10.1051/matecconf/201824005015.

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The article covers the CFD analysis of the compressed air rotary lobe expander. Compressed air engines are commonly used in the explosion hazard zones, where the others power sources cannot be applied. The lobe construction seems to be cheaper solution in comparison with the classic turbine expanders at the corresponding power level. In the paper the rotary lobe compressed air expander model was developed in the ANSYS CFX software. During implementation of the proposed numerical model the mesh motion problem was solved, which was challenging due to relatively small gaps between lobes and the housing as well as due to high rotary speed of lobes. What is more, the compressible fluid model was applied. Therefore, these conditions make the undertaken problem more complex and calculation more time consuming. Finally, the model was validated applying the catalogue data of the producer. In the paper description of the developed model was presented. Then the results of simulations with their validation were shown which proved the correctness and accuracy of the model. The developed tool might be very useful for the further analysis of the expander including its optimization in terms of improvement of its efficiency or energy gain.

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15

Afiq, Aiman Dahlan, Amirah Haziqah Zulkifli, Nasution Henry, Abdul Aziz Azhar, Mohd Rozi Mohd Perang y Hishammudin Mohd Jamil. "Performance Study of Electric Compressor in Non-Electric Vehicle". Applied Mechanics and Materials 554 (junio de 2014): 464–68. http://dx.doi.org/10.4028/www.scientific.net/amm.554.464.

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The usage of electric compressor inside conventional non-electric vehicle is a new shifts in current vehicle air conditioning system which currently using belt-driven compressor to operate. The usage of belt-driven compressor causes the compressor speed to vary with engine speed rotation, which we cannot control. The usage of electric compressor to replace the belt-driven compressor makes the speed to be according to the cooling load and thus reducing engine load. The current research activity focuses on the development of electric compressor using direct current (DC) from vehicles battery to replace current belt-driven in vehicle air conditioning system. Performance study is focusing on temperature inside cabin, cooling capacity, compressor power consumption and coefficient of performance (COP). The DC compressor speed is varying at 1800, 2000, 2200, 2400, 2500 and 3000 rpm at internal heat load of 1000W with temperature set-point of 20°C. The system uses On/Off controller and compared to belt-driven compressor. The overall experimental results in better energy efficiency at the expense of lower cooling capacity.

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Ivanov, Emilian Octavian y Costel Ungureanu. "Design of a submarine main ballast blowing systems". Analele Universităţii "Dunărea de Jos" din Galaţi Fascicula XI Construcţii navale/ Annals of "Dunărea de Jos" of Galati Fascicle XI Shipbuilding 46 (4 de diciembre de 2023): 147–54. http://dx.doi.org/10.35219/annugalshipbuilding/2023.46.18.

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A submarine ballast system represents a combination of dedicated equipment and piping in which the main circulating fluid is either sea water straight from the submarine exterior or air which is compressed at high pressures and then it is stored in pressure vessels onboard. These fluids are, then, introduced in or extracted from various tanks located strategically onboard the submerged vehicle. Because water cannot be compressed and because of it’s density, it will require large amounts of energy and pumps to be able to move all the water within the system in a short period of time that is required for surfacing a submerged vehicle. Therefore, compressed air is favoured for the main deballasting because of the air’s capability of being stored at high pressures and displacing water in a fast manner once it is fed into the ballast tanks, thanks to it’s ability to expand as the submarine emerges and the surrounding water pressure drops. In addition, the compressed air systems must operate for at least a normal surfacing from periscopie depth, but also for surfacing from the maximum depth in the case of an emergency. From an engineering standpoint, ballast tank blowing systems are complex, but nevertheless are vital, for allowing the maneuvering of the submarine and it’s bouyancy within the water it navigates, regardless if it’s in a surfaced or submerged condition and must be done in the smoothest and with as little noise as possible. The requirements of designing and calculation of such systems are covered by the Class and Administration rules and regulations.

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17

Zhygalov, Ia A., V. V. Inyushev, V. O. Posokh, S. A. Vyzhva y I. I. Onyshchuk. "Experimental research of the air permeability of concrete in the compressed zone of the containment for power units no. 1, 2 of the South-Ukrainian NPP". Nuclear Power and the Environment 20 (2021): 39–50. http://dx.doi.org/10.31717/2311-8253.21.1.3.

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The determination of the air permeability of concrete in the compressed zone of NPP’s containment under conditions of excessive air pressure in the subshell space of the reactor compartment under a maximum design basis accident is necessary to confirm the localizing functions of the containment when extending the lifetime of power units. Approaches to determining the localizing ability (air permeability) of concrete in the compressed zone of the containment of NPPs with WWER-1000 type reactors under the impact of excessive air pressure under conditions of maximum design basis accident are discussed in the article. The designed testing installation for experimental studies of the air permeability of concrete by the method of stationary radial filtration is described and the results of experimental researches of the air permeability on the installation are presented for samples simulating the composition of concrete used under construction of the containment for Power Units No. 1, 2 (series B-302 and B-338, respectively) SD “South-Ukrainian NPP”. A comparative analysis of the results of abovementioned experimental researches with the results of experimental and theoretical work on the study of air permeability of the similar samples-imitators of concrete by the method of stationary linear filtration, as well as the results of measurements for samples of concrete sampled directly from the compressed zone of containment for Power Unit No. 2 of SD “South-Ukrainian NPP” was fulfilled. The results are explained by processes of compaction of the concrete structure under a complex stress state that occurs under specific hardening conditions and during longtime compression by pre-stressed reinforcing ropes, which takes place under conditions of real containment operation. It was concluded that the simulators made according to the currently accepted technology cannot provide a correct determination of the localizing ability of the NPP’s containment, since the conditions and time of containment concrete hardening, as well as the longtime constant compressive action of reinforcing ropes, cannot be correctly modeled in full under the formation of samples-imitators. The issue of the containment concrete samplesimitators creating in laboratory conditions requires additional study, improvement of technology and the development of new approaches with maximum physical modeling of the conditions characteristic of the operation of the NPP containment.

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18

Zhang, Ao y Hongyuan Sun. "Dynamics Analysis of a Rolling Rotor Compressor Considering the Electromagnetic Force". Journal of Computing and Electronic Information Management 10, n.º 3 (24 de mayo de 2023): 91–94. http://dx.doi.org/10.54097/jceim.v10i3.8708.

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Rolling rotor compressor is a commonly used compressor in air conditioning systems, and studying its internal dynamic characteristics plays an important role in the vibration and noise of air conditioning systems. Due to the integration of the motor rotor and shaft inside the compressor, the influence of electromagnetic force needs to be considered when analyzing the dynamics of the compressor. This paper studies the rotor dynamics characteristics of a rolling rotor compressor, considering not only the bearing force and gas force inside the cylinder, but also the electromagnetic force of the motor rotor. Firstly, the gas force, electromagnetic force, and bearing force on the compressor shaft are analyzed; Secondly, a two degree of freedom rotor bearing dynamic model of the compressor shaft is established, and the dynamic characteristics of the shaft are obtained by solving the model though the Runge-Kutta method; Finally, the vibration characteristics of the compressor shaft are analyzed in both the time and frequency domains. The results indicate that the influence of electromagnetic force cannot be ignored, and the coupling effect between electromagnetic force and bearing force can be seen.

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Wan, Fa y Zhong-Ming Jiang. "Seepage and Heat Transfer Characteristics of Gas Leakage under the Condition of CAES Air Reservoir Cracking". Geofluids 2021 (27 de julio de 2021): 1–18. http://dx.doi.org/10.1155/2021/5182378.

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The contradiction between supply and demand of energy leads to more and more attention on the large-scale energy storage technology; Compressed Air Energy Storage (CAES) technology is a new energy storage technology that is widely concerned in the world. The research of coupled heat transfer and seepage in fractured surrounding rocks is the necessary basis to evaluate the operation safety and effectiveness of CAES. Current studies point to the possibility of cracking in concrete liner seals, but the thermodynamic processes and leakage characteristics of compressed air in the presence of cracking and the heat transfer characteristics of seepage have not been addressed and reported. In order to investigate the leakage, the gas seepage and heat transfer law in fractured rock when the hard rock CAES gas reservoir seal cracks, the COMSOL fracture Darcy module, and the non-Darcy Forchheimer model are used as the constitutive seepage. The global ODE is used to calculate the thermodynamic process of compressed air in gas storage with coupled seepage and heat transfer process. The pressure and temperature of compressed air are obtained as the unsteady boundary of the seepage heat transfer model. A program for calculating the seepage and heat transfer characteristics of fractured surrounding rock in the CAES gas reservoir is established. On this basis, with the proposed Suichang CAES cavern as the background, the seepage and heat transfer characteristics of the fractured surrounding rock of the gas storage are studied. The results showed that when there are fewer cracks in the lining and surrounding rock of the air reservoir, the air pressure decreases due to a small amount of air leakage after 30 operation cycles, and the leakage rate of each cycle is 0.7% of the gas storage capacity, but it still meets the engineering requirements. If the plant is operating under these conditions, the charging rate will need to be increased by 1.2 kg/s per cycle charging stage. In the discharging and power generation phase, the high-pressure air that previously percolated into the rock mass cracks could flow back into the air storage through the lining cracks. Therefore, it is incorrect and unreliable to consider the gas which flows out from the inner surface of the lining as unusable. When the lining crack width is less than 0.3 mm, the seepage flow is Darcy flow and the non-Darcy effect can be ignored; when the lining crack width is greater than 0.5 mm, the non-Darcy effect of seepage cannot be ignored. The gas velocity in the surrounding rock fracture medium is on the order of 0.01 m/s with an influence range of over 100 m, and the gas velocity in the pore medium is on the order of 10-6 m/s with an influence range of 50 m. The findings of this study contribute to a better understanding of the interaction between the thermodynamic properties of compressed air and the seepage heat transfer process in compressed air storage underground reservoirs, as well as the gas leakage process in the event of liner seal cracking.

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Kurdi, Ojo, Saziana binti Samat, Mohd Azam bin Mohd Adnan, Muhammad Ilham bin Khalit, Zahirrudin bin Idris, Muhammad Nazir bin Mohammed Khalid, Ian Yulianti y Ridzuan bin Marawi. "Wall Thickness Optimization of High Powered Portable Multifunction Air Compressor Tank Using Finite Element Method". Applied Mechanics and Materials 695 (noviembre de 2014): 746–49. http://dx.doi.org/10.4028/www.scientific.net/amm.695.746.

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Air compressor tank is the important equipment in the automotive workshops and laboratories. Air compressor can be categorized as pressure vessel. Pressure vessel often has a combination of high pressure together with high temperature, in some cases of flammable fluids or highly radioactive material. Due to hazards, it is crucial to ensure there is no leakage on the products. In addition, vessel has to be design cautiously to cope with the operating temperature and pressure. The thickness of the PMAC should be optimized to get the best performance, the thickness cannot be very large due to the cost of material and exceeded weight and also cannot be very thin due to the failures caused by its internal pressure. In order to get the optimum thickness, finite element method software was used to simulate the stress analysis of PMAC with various thickness and various shapes.

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21

GÜNGÖR ÇELİK, Ayşegül. "Advanced Exergy Assessment of an Air Source Heat Pump Unit". Bitlis Eren Üniversitesi Fen Bilimleri Dergisi 13, n.º 1 (25 de diciembre de 2023): 15–22. http://dx.doi.org/10.17798/bitlisfen.1308933.

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Conventional exergy-based analysis methods are used for evaluating the performance of the energy conversation systems. Conventional exergy-based analyses identify the sources, amounts, and reasons of irreversibilities (exergy destructions), costs and environmental effects, and provide a general direction for improvement. However, interactions between system components (endogenous/exogenous) and technical limitations (avoidable/unavoidable) cannot be identified with any conventional analysis. Hence, the real potential for improvement and optimization strategies can be misguided. Advanced exergy based analysis seeks to overcome this limitation. An air source heat pump unit was assessed applying conventional and advanced exergy analysis approaches respectively. Avoidable/unavoidable and endogenous/exogenous exergy destructions, modified exergy efficiencies and modified exergy losses ratios were calculated for every single component of the system. The results showed that while the evaporator and condenser efficiencies could be upgraded via constructional enhancements to the overall system and other system components, internal operating conditions were mainly responsible of the inefficiencies regarding with the compressor. The analysis demonstrated that while it was possible to improve evaporator and condenser efficiency by making constructive enhancements to whole system design, the efficiency of the compressor was mainly determined by the internal conditions in which the compressor operated.

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22

Chen, A. G., Daniel J. Maloney y William H. Day. "Humid Air NOx Reduction Effect on Liquid Fuel Combustion". Journal of Engineering for Gas Turbines and Power 126, n.º 1 (1 de enero de 2004): 69–74. http://dx.doi.org/10.1115/1.1615255.

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An experimental investigation was carried out at DOE NETL on the humid air combustion process using liquid fuel to determine the effects of humidity on pollutant emissions and flame stability. Tests were conducted at pressures of up to 100 psia (690 kPa), and a typical inlet air temperature of 860°F (733 K). The emissions and RMS pressures were documented for a relatively wide range of flame temperature from 2440-3090°F (1610–1970 K) with and without added humidity. The results show more than 90% reduction of NOx through 10% humidity addition to the compressed air compared with the dry case at the same flame temperature. The substantial reduction of NOx is due to a shift in the chemical mechanisms and cannot be explained by flame temperature reduction due to added moisture since the comparison was made for the same flame temperature.

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23

Sidorovskaia, Natalia y Kun Li. "Marine compressed air source array primary acoustic field characterization from at-sea measurements". Journal of the Acoustical Society of America 151, n.º 6 (junio de 2022): 3957–78. http://dx.doi.org/10.1121/10.0011678.

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The primary acoustic field of a standard seismic survey source array is described based on a calibrated dataset collected in the Gulf of Mexico. Three vertical array moorings were deployed to measure the full dynamic range and bandwidth of the acoustic field emitted by the compressed air source array. The designated source vessel followed a specified set of survey lines to provide a dataset with broad coverage of ranges and departure angles from the array. Acoustic metrics relevant to criteria associated with potential impacts on marine life are calculated from the recorded data. Sound pressure levels from direct arrivals exhibit large variability for a fixed distance between source and receiver; this indicates that the distance cannot be reliably used as a single parameter to derive meaningful exposure levels for a moving source array. The far-field acoustic metrics' variations with distance along the true acoustic path for a narrow angular bin are accurately predicted using a simplified model of the surface-affected source waveform, which is a function of the direction. The presented acoustic metrics can be used for benchmarking existing source/propagation models for predicting acoustic fields of seismic source arrays and developing simplified data-supported models for environmental impact assessments.

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Прохоренко, Андрій Олексійович, Сергій Сергійович Кравченко, Олександр Васильович Грицюк y Анатолій Петрович Кузьменко. "ВИБІР ТА ОБҐРУНТУВАННЯ СХЕМИ НАДДУВУ ДИЗЕЛЯ АВІАЦІЙНОГО ПРИЗНАЧЕННЯ". Aerospace technic and technology, n.º 1 (26 de febrero de 2021): 75–83. http://dx.doi.org/10.32620/aktt.2021.1.08.

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The article provides the substantiation of the rational scheme of the boost system of the aircraft diesel engine KhADI-100A to ensure its altitude from the point of view of the lowest losses of the effective engine power. A method is proposed for assessing the power loss of an aircraft diesel engine depending on the flight altitude. Three variants of the supercharging system are considered: with one free turbocharger; parallel drive compressor and free turbocharger; sequential drive compressor and free turbocharger. As a result of the computational study, it was shown that in the case of using one free turbocharger at an altitude of h > 1500 m, the normal operating process of a diesel engine cannot be realized, since in this case, the excess air ratio falls below the critical value for a diesel engine α <1.4. Even if a constant excess air ratio is maintained, the effective engine power, with one free turbocharger, decreases by about 6 ... 11 kW per 1000 m with an increase in flight altitude. In schemes with a driving compressor, the quality of the fuel-air mixture will not change with altitude, and the power losses for their drive are insignificant in comparison - within 1 ... 2 kW per 1000 m of lifting height and can be compensated by increasing the cycle fuel supply without losing the quality of the working process. As a result of the computational study, it was concluded that the most rational from the point of view of the least power consumption is the scheme with a sequential drive compressor and a free turbocharger, the power consumption for the compressor drive at an altitude of 5000 m is 1.4 kW less than in the scheme with a parallel drive compressor and is the maximum value of 8.5 kW. The use of an electrically driven compressor is proposed since in this case the unit gains control flexibility to select the optimal operating mode and the possibility of using alternative energy sources for the drive electric generator (solar batteries, accumulators, thermoelectric generators, etc.).

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Waghmare, Atul C., Pihu Ghodeswar, Tushar Khot, Buddhabhushan Gawande, Mohd Sohel y Sahil Wagh. "Design and Fabrication of Gravity Based Energy Storage System". International Journal for Research in Applied Science and Engineering Technology 11, n.º 5 (31 de mayo de 2023): 598–600. http://dx.doi.org/10.22214/ijraset.2023.51231.

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Abstract: Renewable energy sources are increasingly fulfilling the need for continuous energy supply. However, energy derived from these sources cannot be directly utilized and must be stored in energy storage systems such as Battery Energy Storage Systems (BESS), Compressed air systems, Mechanical systems, Hydraulic systems, among others. In this paper, we will discuss the study and analysis of a Gravity-based energy storage system and its fabrication of a model-based representation. The objective is to improve the overall concept and efficiency of the system. Gravity-based energy storage systems utilize gravity's force to store potential energy. The system functions by elevating a heavy object to a high altitude and subsequently releasing it to generate electricity. The lifting motion stores potential energy, which is then converted to kinetic energy as the weight descends and can be used to produce electricity. The paper will provide additional information about the specific gravity-based energy storage system being analysed, as there are different designs and configurations. Additionally, the paper will compare and contrast this method of energy storage with other methods such as battery storage and compressed air storage, highlighting the advantages and disadvantages of each. Lastly, the paper will touch on the development and testing of a physical model or simulation of the gravity-based energy storage system. The paper will provide details on the design and testing process, as well as any modifications or improvements made to the system based on the findings

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26

Mehraban, Karim Maghsoudi, Seyyed Vahid Mahmoodi Jezeh y Seyyed Hossein Musa Kazemi. "Technical and Economical Evaluation of Media and Fog Systems in Fars, Qom, Yazd, Shahid Rajaee Power Plants". Advanced Materials Research 433-440 (enero de 2012): 7229–33. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.7229.

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In the hot days of summer, the efficiency of gas turbine is extremely reduced because the input air to compressors becomes hot. For solving this problem, one can increase the efficiency of the power house by charging to decrease the input air temperature to the compressor of gas turbine. In this paper, all kinds of cooling the inlet air to the gas turbine are introduced and then the technical and economical evaluation of these installed cooling system in Shahid Rajaee, Qom, Fars and Yazd power plants are expressed and the results show that the fog system cannot prove its effectiveness in Shahid Rajaee and Qom power plants. Whereas the installation of media systems in Fars combined cycle power plant produces more megawatt than its guarantee conditions and no particular problem has been observed.

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27

Xia, Yan Chun y Dong Xiao. "The Application of SPC in the Motor Production Operation of the Air Conditioning Compressor". Applied Mechanics and Materials 120 (octubre de 2011): 304–10. http://dx.doi.org/10.4028/www.scientific.net/amm.120.304.

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Motor is the key part of the air conditioner compressor. And the production process of the motor will often encounter some quality defects. One of the most common defects is machine winding paint film injury. In the past, salt pinhole test and brush test are common means for product quality control in many companies. Although in such trials, some quality problem can be found, it is a single method for site quality management and is a kind of method of remedying afterwards. It often cannot find or visualized find by chart the bad trend timely. Statistical process control (SPC) is a different method, which can implement real-time monitoring and evaluation in each stage of the production process. It is a kind of preventive method. It can carry out the paint damage monitoring and evaluation in the motor manufacturing process very well, using SPC control diagram method.

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28

Chen, Meng, Zhifang Zhou, Brent Sleep, Xingxing Kuang, Li Mingwei y Anchi Shi. "Experimental Study of Water Infiltration in Unsaturated Horizontal Sand Columns under Various Air Confinement Conditions". Geofluids 2019 (18 de diciembre de 2019): 1–13. http://dx.doi.org/10.1155/2019/4270358.

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The process of water infiltration into initially dry sand was studied in horizontal sand columns under various airtight conditions. To investigate the interrelations among water inflow behavior, air pressure, air confinement effect, and vent effectiveness in unsaturated porous media experiencing dynamic infiltration, a total of five dynamic infiltration experiments with fixed inlet water pressure were performed with different air vents open or closed along the column length. Visualizations of the infiltration process were accompanied by measurements of water saturation, air pressure, and accumulated water inflow. In a column system with an open end, the absence of air pressure buildup reveals that the vent at the column end can significantly reduce the internal air pressure effects during infiltration, and the air phase can be ignored for this case. However, in columns with a tight end, the coupled air and water flow processes can be divided into two completely different periods. Before the water front passed by the most distant open vent, the internal air pressure effects on retarding dynamic infiltration are negligible, similar to the open end case. After this period, the open vents can certainly influence the inflow behavior by functioning as air outlets while they cannot equilibrate pore air pressure with the atmospheric pressure. The remaining air ahead of the front will be gradually confined and compressed, and the significant increase in air pressure highlights the great role of air pressure buildup in reducing the water infiltration rate. The closer the last open vent was to the water inlet, the higher was the increase in air pressure and the greater was the delaying effect on water infiltration. This work may extend the experimental study of water infiltration into the unsaturated soils with different airtight conditions and provide experimental evidence on these coupled mechanisms among the water and air phases in soils.

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29

XU, HONGBO, SHUANGQUAN SHAO, HUIMING ZOU y CHANGQING TIAN. "INTEGRATED STEADY-STATE AND DYNAMIC SIMULATION OF MULTI-UNIT AIR CONDITIONERS BASED ON TWO-PHASE FLUID NETWORK MODEL". International Journal of Air-Conditioning and Refrigeration 20, n.º 04 (diciembre de 2012): 1250020. http://dx.doi.org/10.1142/s2010132512500204.

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An integrated simulation model is developed to investigate the steady-state and dynamic performance of multi-unit air conditioners (MUACs). It is built as two-phase fluid network which is able to describe different systems by incidence matrixes. And the submodels are embedded in the system framework, where the submodels can be either steady-state or dynamic model, distributed parameter or lumped parameter model. For this case, the numerical submodels are employed with moving-boundary models of condenser and evaporator, steady-state models of compressor and electronic expansion valve. The comparison with experimental data shows that it cannot only predict the steady-state performance, but also catch dynamic trends with high accuracy, for example, the differences of evaporating pressure < ± 4%, condensing pressure < ± 3%, compressor discharge temperature < ± 4° C , superheating degree < ± 2° C and subcooling degree < ± 1° C . Therefore, the simulation model is confirmed as an effective tool to analyze the steady and transient characteristics and optimize the design and control algorithm of MUACs.

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30

Bhavani, Kompalli y Sivanesan Murugesan. "Diesel to Dual Fuel Conversion Process Development". International Journal of Engineering & Technology 7, n.º 3.6 (4 de julio de 2018): 306. http://dx.doi.org/10.14419/ijet.v7i3.6.15121.

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This paper aims to develop a process for conversion of Diesel Engine for Dual Fuel operation which is basically designed to reduce the economic costs and pollutant Emissions. The increasing cost of Diesel Fuel leads to the necessity of an Alternate fuel, i.e Compressed Natural gas (CNG). In this research a 16 cylinder, 50.25liter, Turbocharged After cooler V-shaped Engine is used for the conversion into Dual Fuel Engine. Dual fuel engine can be operated on both Diesel and CNG modes simultaneously. In this Engine the Air and CNG are mixed in required ratios in an Air- Gas mixer and the mixture is injected into the Combustion chamber. As Gaseous fuel CNG cannot self-ignite itself because of its high Auto ignition temperature a required amount of Diesel is injected into the Combustion Chamber at the end of compression stroke for ignition purpose which is known as Secondary fuel or a PILOTFUEL. This paper tries to show the process development of converting Diesel Engine for dual fuel operation on multiple platforms.

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31

Tao, R. "Can we eliminate major tornadoes in Tornado Alley? — Response to the Comments". International Journal of Modern Physics B 28, n.º 29 (20 de noviembre de 2014): 1475005. http://dx.doi.org/10.1142/s0217979214750058.

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Dahl and Markowski are wrong and misleading to claim that the major tornadoes in USA Tornado Alley are not related to the collisions between northbound warm air flow and southbound cold air flow. In addition, they use incompressible and inviscid fluid model for atmosphere in their simulations about the interaction between air wind and the wall. Such approach ignores the basic physics and thus cannot reach any meaningful results. As air is compressible, the collision between the wind and wall will compress air, eventually lead the air density to decrease fast with the height and make the air flow stratified. The viscosity will produce wind shear, turbulent eddies and greatly reduce the wind's forwarding speed. Laboratory experiments and the Nature have all shown that hills with height about 300 m will not block winds completely to change the climate, but can effectively reduce the wind speed, weaken the air mass collisions and eliminate the major tornadoes. All these strongly support the theory that building east–west ranged walls of 300 m high and 50 m wide will eliminate major tornado threat in Tornado Alley.

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32

Chen, Qifan y Hang Xu. "Application Status and Development Prospect of Liquid Air Energy Storage". Highlights in Science, Engineering and Technology 26 (30 de diciembre de 2022): 102–10. http://dx.doi.org/10.54097/hset.v26i.3657.

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The growth of the energy storage sector has garnered increasing attention from nations in recent years. In recent years, the energy storage sector has grown at a rate that has outpaced the expansion of the power sector in terms of real industrial output and application. Due to the obvious growth of renewable energy, there is a sizable market potential for the development of the energy storage industry, which is mostly represented by wind and light. Yet, there is still demand to integrate renewable energy into the grid on a wide scale and run safely and steadily because new energy sources are sometimes available and sometimes not, so they cannot provide a steady, reliable source of power directly by themselves. The aforementioned issues can be successfully resolved through the utilization of technological advancements in energy storage on a grand scale. There are many different ways to store energy, but some of the most common large-scale methods are using batteries, hydroelectric dams, and compressed air. As a novel form of cryogenic technology, liquid air energy storage (LAES) represents a significant step forward in energy storage. It can realize grid-connected new energy consumption, reasonably absorbs low-valley electricity and waste heat resources, and can steadily output various energy sources, including cold, heat, electricity, and industrial gas. This article will discuss the basic principles of LAES and its integrated systems and hope to facilitate future efficient energy storage and renewable energy usage by using LAES technology.

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Putra, Karisma Trinanda, Hsing-Chung Chen, Prayitno, Marek R. Ogiela, Chao-Lung Chou, Chien-Erh Weng y Zon-Yin Shae. "Federated Compressed Learning Edge Computing Framework with Ensuring Data Privacy for PM2.5 Prediction in Smart City Sensing Applications". Sensors 21, n.º 13 (4 de julio de 2021): 4586. http://dx.doi.org/10.3390/s21134586.

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The sparse data in PM2.5 air quality monitoring systems is frequently happened on large-scale smart city sensing applications, which is collected via massive sensors. Moreover, it could be affected by inefficient node deployment, insufficient communication, and fragmented records, which is the main challenge of the high-resolution prediction system. In addition, data privacy in the existing centralized air quality prediction system cannot be ensured because the data which are mined from end sensory nodes constantly exposed to the network. Therefore, this paper proposes a novel edge computing framework, named Federated Compressed Learning (FCL), which provides efficient data generation while ensuring data privacy for PM2.5 predictions in the application of smart city sensing. The proposed scheme inherits the basic ideas of the compression technique, regional joint learning, and considers a secure data exchange. Thus, it could reduce the data quantity while preserving data privacy. This study would like to develop a green energy-based wireless sensing network system by using FCL edge computing framework. It is also one of key technologies of software and hardware co-design for reconfigurable and customized sensing devices application. Consequently, the prototypes are developed in order to validate the performances of the proposed framework. The results show that the data consumption is reduced by more than 95% with an error rate below 5%. Finally, the prediction results based on the FCL will generate slightly lower accuracy compared with centralized training. However, the data could be heavily compacted and securely transmitted in WSNs.

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34

Weigl, H. J., J. D. Paduano, L. G. Fre´chette, A. H. Epstein, E. M. Greitzer, M. M. Bright y A. J. Strazisar. "1997 Best Paper Award—Controls and Diagnostics Committee: Active Stabilization of Rotating Stall and Surge in a Transonic Single-Stage Axial Compressor". Journal of Turbomachinery 120, n.º 4 (1 de octubre de 1998): 625–36. http://dx.doi.org/10.1115/1.2841772.

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Rotating stall and surge have been stabilized in a transonic single-stage axial compressor using active feedback control. The control strategy is to sense upstream wall static pressure patterns and feed back the signal to an annular array of twelve separately modulated air injectors. At tip relative Mach numbers of 1.0 and 1.5 the control achieved 11 and 3.5 percent reductions in stalling mass flow, respectively, with injection adding 3.6 percent of the design compressor mass flow. The aerodynamic effects of the injection have also been examined. At a tip Mach number, Mtip, of 1.0, the stall inception dynamics and effective active control strategies are similar to results for low-speed axial compressors. The range extension was achieved by individually damping the first and second spatial harmonics of the prestall perturbations using constant gain feedback. At a Mtip of 1.5 (design rotor speed), the prestall dynamics are different than at the lower speed. Both one-dimensional (surge) and two-dimensional (rotating stall) perturbations needed to be stabilized to increase the compressor operating range. At design speed, the instability was initiated by approximately ten rotor revolutions of rotating stall followed by classic surge cycles. In accord with the results from a compressible stall inception analysis, the zeroth, first, and second spatial harmonics each include more than one lightly damped mode, which can grow into the large amplitude instability. Forced response testing identified several modes traveling up to 150 percent of rotor speed for the first three spatial harmonics; simple constant gain control cannot damp all of these modes and thus cannot stabilize the compressor at this speed. A dynamic, model-based robust controller was therefore used to stabilize the multiple modes that comprise the first three harmonic perturbations in this transonic region of operation.

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35

Kumar Singh, Nishant, Sandeep Agrawal, Rajvardhan . y Yashvir Singh. "Experimental Study and Parameter Optimization of Hybrid Electrical Discharge Machining". International Journal of Engineering & Technology 7, n.º 3.12 (20 de julio de 2018): 1161. http://dx.doi.org/10.14419/ijet.v7i3.12.17780.

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Hard materials cannot be machined effectively by the individual machining process. In order to machine workpiece made from hard and stiff materials effectively a concept of Hybrid machining process (HMP) is originated. The HMP is an integration of two or more machining process to get the advantage of each individual process. HMP is used to machine This study focuses on evolving a novel process using both oil and gas as dielectrics to analyse the effect on tool wear rate (TWR) and material removal rate (MRR). The flow of compressed gas through eccentric-hole rotating tool improved the debris removal from inter-electrode gap, hence it improve the flushing competence of the machining process. In this experimental investigation, the workpiece material is Al-20% SiC metal matrix composite (MMC) and the electrode material is copper. The experiments were conducted following the Taguchi method of design experiments. The effect of various machining parameters on MRR and TWR has been studied. The optimization of process parameter has also been done. The results of TWR and MRR are analysed using S/N ratio, ANOVA and main effect plots. The experimental results, revels that discharge current, gap voltage and pulse on time significantly affected MRR, and TWR. The experimental inference reveal that provision of compressed air through eccentric hole rotary tool has a positive effect on machinability of electrical discharge machining (EDM) process.

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36

Miller, John, Scott Lehman, Chad Wolak, Jocelyn Turnbull, Gregory Dunn, Heather Graven, Ralph Keeling et al. "Initial Results of an Intercomparison of AMS-Based Atmospheric 14CO2 Measurements". Radiocarbon 55, n.º 3 (2013): 1475–83. http://dx.doi.org/10.1017/s0033822200048402.

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This article presents results from the first 3 rounds of an international intercomparison of measurements of Δ14CO2 in liter-scale samples of whole air by groups using accelerator mass spectrometry (AMS). The ultimate goal of the intercomparison is to allow the merging of Δ14CO2 data from different groups, with the confidence that differences in the data are geophysical gradients and not artifacts of calibration. Eight groups have participated in at least 1 round of the intercomparison, which has so far included 3 rounds of air distribution between 2007 and 2010. The comparison is intended to be ongoing, so that: a) the community obtains a regular assessment of differences between laboratories; and b) individual laboratories can begin to assess the long-term repeatability of their measurements of the same source air. Air used in the intercomparison was compressed into 2 high-pressure cylinders in 2005 and 2006 at Niwot Ridge, Colorado (USA), with one of the tanks “spiked” with fossil CO2, so that the 2 tanks span the range of Δ14CO2 typically encountered when measuring air from both remote background locations and polluted urban ones. Three groups show interlaboratory comparability within l% for ambient level Δ14CO2. For high CO2/low Δ14CO2 air, 4 laboratories showed comparability within 2%. This approaches the goals set out by the World Meteorological Organization (WMO) CO2 Measurements Experts Group in 2005. One important observation is that single-sample precisions typically reported by the AMS community cannot always explain the observed differences within and between laboratories. This emphasizes the need to use long-term repeatability as a metric for measurement precision, especially in the context of long-term atmospheric monitoring.

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37

Li, Ting, Yuchuan Wang, Xiuli Mao, Diyi Chen, Rui Huang y Quanke Feng. "Development and Experimental Study of the First Stage in a Two-Stage Water-Flooded Single-Screw Compressor Unit for Polyethylene Terephthalate Bottle Blowing System". Energies 13, n.º 16 (16 de agosto de 2020): 4232. http://dx.doi.org/10.3390/en13164232.

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The oil-free compressor is a key component in fabricating polyethylene terephthalate (PET) bottles for beverages and water. At present, the main compressor type used for blowing PET bottles is the reciprocating compressor. However, compared to screw compressors, reciprocating compressors have shortcomings of high energy consumption and too many consumable parts. Many manufacturers of PET bottles in Asia are seeking to replace reciprocating compressors with screw compressors, as we know. Screw compressors can be classified as single-screw compressors (SSC) and twin-screw compressors. Since the load in a twin-screw compressor is far larger than that in an SSC, SSCs are more suitable for being developed for high-pressure applications such as PET bottle blowing. This paper presents a performance study on an oil-free single-screw compressor as the first stage of the PET compressor unit. A 5.4 m3·min−1 prototype and its test rig were developed. The thermophysical process of the moist air is theoretically analyzed. The pressure loss on the flow path and the influence of the important parameters are experimentally investigated. It is found that water vapor cannot be separated during the adiabatic compression process. The results also show that the pressure loss from the discharging duct to the check valve accounts for the largest percentage of the total pressure loss. The experimental results further show that the discharge capacity and shaft power increase almost linearly with the motor speed. The efficiency declines with increasing injected water temperature. The discharge capacity and shaft power all increase with the injected water flowrate, and an optimum flowrate is found to ensure a highest isentropic efficiency. With the increase in discharge pressure, the discharge capacity decreases, and the shaft power increases. The isentropic efficiency is found to have its maximum value at a certain discharge pressure.

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38

Athrey, Prajwal L. "Design and Fabrication of Exoskeleton Arm for Lifting Weight". International Journal for Research in Applied Science and Engineering Technology 10, n.º 6 (30 de junio de 2022): 4931–32. http://dx.doi.org/10.22214/ijraset.2022.45127.

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Abstract: For centuries now, humans have developed machines for tasks which are too labour intensive for species cannot do. So, creative imagination and subtle engineering has led to the development of the powered exoskeleton. It is a device which can be worn over the human body. The robotic exoskeleton systems are developed significantly to be used for human power assist and haptic interaction with human Motion. The designed pneumatic arm consists of cylinders, a shaft efforts with lead screw mechanism able of converting a movement of piston to rotational movement of arm by utilizing the compressed air from pneumatic system. The designed processes of the suit is carried out based on some integrated information of kinematic, dynamics and structural analysis of the desired exoskeleton configuration as a whole. Since, such exoskeleton directly interacts with a human body there are some mechanical limitations to its design. While designing such exoskeleton movable range of arms, safety and comfort Wearing, low inertia, adaptability are considered.

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Pangelis, S., S. R. Olsen, J. Scherschligt, J. B. Leão, S. A. Pullen, D. Dender, J. R. Hester y P. Imperia. "Safety interlock and vent system to alleviate potentially dangerous ice blockage of top-loading cryostat sample sticks". Journal of Applied Crystallography 46, n.º 4 (22 de junio de 2013): 1236–39. http://dx.doi.org/10.1107/s0021889813010868.

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A combined solution is presented for minimizing the safety hazards associated with closed cycle cryostats described by Swainson & Cranswick [J. Appl. Cryst.(2010),43, 206–210]. The initial solution is to install a vent tube with one open end deep inside the sample space and a pressure relief valve at the top. This solution works for either a cryogen or a cryogen-free (closed cycle) system. The second approach, which can be combined with the first and is applicable to cryogen-free cryostats, involves electrically interlocking the closed cycle refrigerator compressor to the sample space, so that the system cannot be cooled in the presence of a leak path to air.

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40

Om Prasaad, J., A. B. Krishnan, Parth Lokhande y Biradar Mustaffa. "Design and Development of Pneumatic Sheet Metal Cutting Machine". IOP Conference Series: Materials Science and Engineering 1259, n.º 1 (1 de octubre de 2022): 012020. http://dx.doi.org/10.1088/1757-899x/1259/1/012020.

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Abstract A Pneumatic sheet metal cutting machine, is a mechanism designed to cut metal sheets at a quick pace, based on the inputs given by the operator, using a switch. The machine consists of a cutter blade system, a double acting pneumatic cylinder held over the cutter blade system, an air compressor, a pneumatic valve to regulate the air flow to the pneumatic cylinder from the compressor, and a frame to hold the machine in position. Cutting and shearing technology used nowadays, includes laser cutting, hydraulic cutters, among others. These machines are costly, with expensive maintenance. Small and medium scale industries cannot tend to afford this technology. Currently basic sheet metal cutting operations are incorporated in such industries including basic handheld sheet cutters. This is not accurate in terms of the dimensions of the final output and poses safety hazards to the operator too. Thus, the novelty of this machine is that it provides an automated system to cut aluminium sheet metal, while making sure that the system is compact and portable, which has otherwise not been implemented in industries. Pneumatic sheet metal cutters find a tremendous scope in such industries owing to their simple and easy working, low cost and ensured safety with a good degree of dimensional accuracy. The main aim of this study is to research and innovate a safe and efficient way to cut aluminium sheets at a fast and regular pace, as compared to manual cutting, using a pneumatic system.

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41

Mirmanto Mirmanto, Nurchayati Nurchayati y Zulvavril Tri Handaru. "Effect of Coil Evaporator Positions on Freshwater Production and Heat Transfer Rate". Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 110, n.º 1 (3 de diciembre de 2023): 97–103. http://dx.doi.org/10.37934/arfmts.110.1.97103.

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Human life cannot be separated from water; therefore, water must be fulfilled because it is a basic human need. In the dry season, several regions in Indonesia experience a clean water crisis. This crisis needs to be overcome with methods or equipment that can produce water. Various methods for obtaining clean water were carried out in previous research, but not all methods were suitable for the current condition of Indonesia's territory. One method that could be used in all positions and situations and was suitable for household scales was an air-water harvester machine using a cooling machine. However, this method resulted in less freshwater production. Therefore, the authors were interested to examine the effect of the evaporator positions on the freshwater production and heat transfer rates. This research was carried out experimentally with the working fluid refrigerant R134a. The compressor used was a rotary type 1 PK compressor. This study varied the positions of the coil evaporator, namely the vertical position, the 45° position, and the horizontal position. The highest freshwater production and heat transfer rate were attained using the vertical position. The maximum freshwater production and heat transfer rate were 0.641 kg and 127.17 W respectively.

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Siregar, Muhammad Sapril, Rafi Zidane Shevchenko y Albert Wiweko. "Penyebab Menurunnya Kinerja Mesin Pendingin di MV. Vancouver". Mutiara : Jurnal Ilmiah Multidisiplin Indonesia 1, n.º 2 (31 de octubre de 2023): 89–100. http://dx.doi.org/10.61404/jimi.v1i2.13.

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A cooling machine or commonly called an Air Conditioner (AC) is a system of auxiliary machines that can create cool temperatures in certain rooms so that workers on ships feel comfortable. Cooling machines are used to regulate and manage air quality which are includes air circulation, air conditioning, air hygiene standards and air purification. There are several main components in the cooling machine, namely the Compressor, Condenser, Expansion Valve, Evaporator. Each of these important components has different functions and ways of operating, but are connected to each other so that the cooling machine can function. The purpose of the author making this final project is to determine the performance of the cooling system, factors that reduce the performance of the cooling machine, as well as repair and maintenance efforts so that the cooling machine can return to normal operation. This research was conducted on the MV. Vancouver by using a qualitative approach. The author conducted direct observations as well as in-depth interviews and documentation studies when conducting research. The results of the author's research found that the main factor causing the decline in the performance of the cooling machine was the appearance of sparks on the evaporator and coil pipe caused by interference with the filter dryer so that it inhibits heat absorption and the evaporator cannot evaporate the refrigerant optimally. The impact caused by the less than optimal operation of the cooling machine in the Engine Room Workshop MV. Vancouver was an unstable room temperature making the crew feel uncomfortable while working or resting.

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Krichen, Moez, Yasir Basheer, Saeed Mian Qaisar y Asad Waqar. "A Survey on Energy Storage: Techniques and Challenges". Energies 16, n.º 5 (27 de febrero de 2023): 2271. http://dx.doi.org/10.3390/en16052271.

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Intermittent renewable energy is becoming increasingly popular, as storing stationary and mobile energy remains a critical focus of attention. Although electricity cannot be stored on any scale, it can be converted to other kinds of energies that can be stored and then reconverted to electricity on demand. Such energy storage systems can be based on batteries, supercapacitors, flywheels, thermal modules, compressed air, and hydro storage. This survey article explores several aspects of energy storage. First, we define the primary difficulties and goals associated with energy storage. Second, we discuss several strategies employed for energy storage and the criteria used to identify the most appropriate technology. In addition, we address the current issues and limitations of energy storage approaches. Third, we shed light on the battery technologies, which are most frequently used in a wide range of applications for energy storage. The usage and types of batteries are described alongside their market shares and social and environmental aspects. Moreover, the recent advances in battery state estimation and cell-balancing mechanisms are reviewed.

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Evdokimov, S. I. y T. E. Gerasimenko. "Combined gravitation-flotation technology for technogenic gold placer concentration". Izvestiya Vuzov. Tsvetnaya Metallurgiya (Universities' Proceedings Non-Ferrous Metallurgy), n.º 4 (12 de agosto de 2021): 4–15. http://dx.doi.org/10.17073/0021-3438-2021-4-4-15.

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Gold recovery from placer washing waste was carried out using a flotation method where circulating rough concentrate is used to increase the recovered metal content in the rougher flotation operation. Moreover, flotation is carried out with a mixture of air with hot steam. Pressure in bubbles drops and their sizes decrease as a result of vapor condensation at the first moment of time under conditions of vapor-air flotation. Heat exchange between the phases worsens when the bubble is compressed, and mass transfer stops at the minimum bubble size, while temperature and vapor pressure in the bubble reach their maximum. As the bubble grows in size, superheated steam becomes saturated and pressure in the bubble decreases resulting in resumed condensation. The bubble surface undergoes damped oscillations. When the bubble surface vibrates, the motion of a slowly developing concentration-capillary Marangoni flow to the center of the interphase film cannot compensate for its thinning by the counter thermocapillary flow with a high hydrodynamic stability potential from the film center to its periphery. The vapor-air flotation results obtained can be interpreted in the context of this mechanism of wetting film stability changes during the vapor-liquid phase transition. Pilot tests of gravity and gravity-flotation technologies for gold extraction from a technogenic placer of gold have been carried out. It has been proved that the main effect of using the developed configuration of the scheme and the mode of flotation with a vapor-air mixture is a decrease in the concentrate yield by ~ 25% rel. while maintaining the achieved level of recovery and concentrate quality. When using the combined technology, the added value of marketable products provides an increase in the value of net discounted income and the return on investment index, and a decrease in their payback period.

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Othman, Rozaiman Suffian, Abu Bakar Sulong y Shahruddin Ibrahim. "Reprocessing Index for Automotive Co-Axial Swash Plate A5". Applied Mechanics and Materials 663 (octubre de 2014): 662–67. http://dx.doi.org/10.4028/www.scientific.net/amm.663.662.

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Recycling is a process that involves the three Rs (reduce, reuse, and recycling) of managing recyclable items such as paper, metal, glass, and plastic. An index system has been established to calibrate the level of processing reliability or cycle reliability with a specific metric that uses reprocessability index (RPI). The subject of this study is a unit of a co-axial compressor automotive air conditioning system that affects the shape, area, and volume of other units of the same system. The main objective of this study is to determine the component life cycle and to formulate recommendations for design changes with a controlled RPI level for the new automotive air conditioning compressor unit based on the original product. Analysis in this study is based on the value of R1, R2, R3, R4, R5, R6, and RPI for each component such as C01 (front cover), C02 (valve plates), C03 (front cylinder body), C04 (rear cylinder body), C05 (piston), C06 (shaft power), C07 (swash plate), C08 (back cover), C09 (inlet valve), and C10 (discharge valve). The RPI values for these components are 7.249, 12.480, 10.869, 10.869, 9.567, 9.578, 7.346, 7.002, 7.532, and 8.239, respectively. All components have an RPI value between 7 and 13, which indicates that they still have a limit on the reprocess ability. Appropriate redesign of a component can alter these RPI values. In this study, two improvements are proposed for the design of the C04. The first redesign shifts the RPI of this component to 23, which indicates thatC04 cannot be reprocessed. The second design reduces the RPI to 8, which improves the reprocessability. Then, the consideration of the research and development engineer for the same or other functions makes the product throughout its life cycle. These approaches can prevent wastage of energy and mineral resources as well as control industrial pollution.

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Catană, Răzvan, Gabriel Dediu, Cornel Tărăbîc y Horațiu Șerbescu. "Performance Calculations of Gas Turbine Engine Components Based on Particular Instrumentation Methods". Applied Sciences 11, n.º 10 (14 de mayo de 2021): 4492. http://dx.doi.org/10.3390/app11104492.

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This paper presents an analytical method to determine various main parameters or performances of engine components when those parameters cannot be directly measured and it is necessary to determine them. Additionally, some variants of instrumentation methods are presented, for example: engine inlet, compressor, turbine or jet nozzle instrumentation. The purpose of the instrumentation methods is to directly measure the possible parameters, which are then used as inputs in a model to determine other parameters or performance metrics. This model is based on gasodynamic process equations, and it is used to compute the air and gas parameters, such as enthalpy and entropy, which are described in polynomial form, thus leading to a more realistic calculation. At the end, this paper presents a practical example of instrumentation applied on a Klimov TV2-117A turboshaft, with a series of experimental results, following the engine testing on the test bench.

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47

Chiesa, P. y G. Lozza. "CO2 Emission Abatement in IGCC Power Plants by Semiclosed Cycles: Part B—With Air-Blown Combustion and CO2 Physical Absorption". Journal of Engineering for Gas Turbines and Power 121, n.º 4 (1 de octubre de 1999): 642–48. http://dx.doi.org/10.1115/1.2818520.

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This paper analyzes the fundamentals of IGCC power plants with carbon dioxide removal systems, by a cycle configuration alternative to the one discussed in Part A (with oxygen-blown combustion). The idea behind this proposal is to overcome the major drawbacks of the previous solution (large oxygen consumption and re-design of the gas turbine unit), by means of a semiclosed cycle using air as the oxidizer. Consequently, combustion gases are largely diluted by nitrogen and cannot be simply compressed to produce liquefied CO2 for storage or disposal. However, CO2 concentration remains high enough to make separation possible by a physical absorption process. It requires a re-pressurization of the flow subtracted from the cycle, with relevant consequences on the plant energy balance. The configuration and the thermodynamic performance of this plant concept are extensively addressed in the paper. As in the first part, the influence of the pressure ratio is discussed, but values similar to the ones adopted in commercial heavy-duty machines provided here acceptable performance. Proper attention was paid to the impact of the absorption process on the energy consumption. The resulting net overall efficiency is again in the 38–39 percent range, with assumptions fully comparable to the ones of Part A. Finally, we demonstrated that the present scheme enables the use of unmodified machines, but large additional equipment is required for exhausts treatment and CO2 separation. A final comparison between the two semiclosed cycle concepts was therefore addressed.

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48

Pontier, Jean-Michel, Nicolas Vallée y Lionel Bourdon. "Bubble-induced platelet aggregation in a rat model of decompression sickness". Journal of Applied Physiology 107, n.º 6 (diciembre de 2009): 1825–29. http://dx.doi.org/10.1152/japplphysiol.91644.2008.

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Previous studies have highlighted that bubble-induced platelet aggregation is a predictor index of decompression sickness (DCS) severity in animals and bubble formation after a single air dive in humans. The present study attempted to investigate plasmatic indexes of the coagulation system and platelet activation in our rat model of DCS. Male Sprague-Dawley rats were assigned to one experimental group with a hyperbaric exposure and one control group maintained at atmospheric pressure. Rats were compressed to 1,000 kPa (90 m saltwater) for 45 min while breathing air. The onset of death time and DCS symptoms were recorded during a 30-min observed period after rats had surfaced. Plasmatic indexes were platelet factor 4 (PF4) for platelet activation, soluble glycoprotein V (sGPV) for thrombin generation, and thrombin-antithrombin complexes for the coagulation system. Blood samples for a platelet count and markers were taken 3 wk before the experimental protocol and within the 30 min after rats had surfaced. We confirmed a correlation between the percent fall in platelet count and DCS severity. Plasmatic levels of sGPV and PF4 were significantly increased after the hyperbaric exposure, with no change in the control group. The present study confirms platelet consumption as a potential index for evaluating decompression stress and DCS severity. The results point to the participation of thrombin generation in the coagulation cascade and platelet activation in bubble-induced platelet aggregation. In our animal model of DCS, the results cannot prejudge the mechanisms of platelet activation between bubble-induced vessel wall injury and bubble-blood component interactions.

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49

Berencsi, Bence Ferenc y Attila Kossa. "Analyzing the Effect of Temperature on Squash Ball Impacts Using High-Speed Camera Recordings". Periodica Polytechnica Mechanical Engineering 65, n.º 4 (24 de septiembre de 2021): 354–62. http://dx.doi.org/10.3311/ppme.18381.

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Description of the impact characteristics of different types of balls has a great importance in sport science and in engineering. The primary objective of the present paper is to investigate the effect of the temperature on the impacts of different types of squash balls from a given company. The shots were performed using a self-built air-cannon. The impacts were recorded by a high-speed camera and the recorded videos were analyzed by an image-processing method based on a background subtraction technique. Summarizing the main dynamical parameters, we can conclude that increasing the initial speed will decrease the contact time, the coefficient of restitution (COR) and the rebound resilience, whereas these parameters increase at elevated temperatures. The compression tests revealed that within the low velocity range the deformation of the ball’s material and not the compression of the inner gas is the main contribution in the force needed to compress the ball. However, when the ball suffers large deformations, the internal air pressure has a huge effect on the rebound behavior. The measurements revealed that there is an optimal initial velocity distinct from the maximum one where the rebound velocity of the ball is higher than in all other cases. From the results we can state that the ball's overall stiffness grows as the temperature increases.

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50

Bär, Raik Martin, Michael Zeilmann, Christoph Nophut, Joachim Kleinert, Karsten Beyer y Tobias Voigt. "Simulation of Energy and Media Demand of Beverage Bottling Plants by Automatic Model Generation". Sustainability 13, n.º 18 (9 de septiembre de 2021): 10089. http://dx.doi.org/10.3390/su131810089.

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Facing environmental challenges, high energy costs and a growing public awareness, the global brewing industry is increasingly publishing ambitious targets toward a more sustainable production. Small and medium-sized enterprises of the brewing and beverage industry cannot ensure energy and media efficiency mainly due to capital and knowledge inadequacy. This article addresses this problem and presents a pragmatic method to determine the energy and media demand. Accordingly, a modeling editor as well as a standardized data structure and automatic simulation parameter determination tools were developed to implement the method. A given production plant can be modeled with adequate details using the presented editor. Based on a configuration file, a holistic simulation model can be generated automatically in a simulation environment. A beverage bottling plant was studied, and the necessary datasets were obtained for implementing the proposed editor and, thereby, the method. It was confirmed that the simulated values of electrical energy and compressed air consumption match the measured empirical data. The measures to increase energy and media efficiency were also found effective. Using the presented method, enterprises of the brewing and beverage industry can easily uncover avenues for potential savings, test the effectiveness of optimization strategies, and substantiate possible investment decisions.

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