Journal articles on the topic 'Chambres des vannes'
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1
Meshalkin, Valery P., Nicolay A. Martsulevich, Oleg M. Flisyuk, Ilia G. Likhachev, and Antony M. Nzioka. "Hydrodynamics of Energy-Efficient Axial-Flow Cyclones for Environmentally Safe Cleaning of Gas and Dust Emissions." Energies 16, no. 2 (January 10, 2023): 816. http://dx.doi.org/10.3390/en16020816.
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We investigated the operation of an axial-flow cyclone as the most promising dust-cleaning equipment based on energy consumption. Numerical solutions were obtained for the gas-solids suspension flow equations in axial flow cyclones with different separation chambers’ geometry using FlowVision software. The chamber’s geometrical features determined the nature of the gas-solids suspension flow, directly affecting the dusty gases’ purification degree. The circulating gas flows and the turbulent “trace” after the swirl generator were found to negatively influence the cyclone efficiency and the hydraulic resistance values. A high chamber height also negatively affected the gas purification since the bulk of dust particles were removed from the gas-solids flow at the initial section. The initial section’s length coincided with the gas-solids suspension’s jet flow zone due to the flow coming off the swirl vanes’ edges. Due to turbulent mixing, the particles’ secondary entrainment and return to the gas flow began to manifest outside this zone. Based on this analysis, it is possible to develop recommendations for choosing the chamber’s geometric parameters, minimizing the influence of the indicated factors. On the basis of this research, it will be possible to ensure cyclones’ high efficiency with significantly lower hydraulic resistance when designing axial-flow cyclones relative to other types of cyclone.
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Han, Fenghui, Zhe Wang, Yijun Mao, Jiajian Tan, and Wenhua Li. "Flow Control of Radial Inlet Chamber and Downstream Effects on a Centrifugal Compressor Stage." Applied Sciences 11, no. 5 (March 1, 2021): 2168. http://dx.doi.org/10.3390/app11052168.
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Radial inlet chambers are widely used in various multistage centrifugal compressors, although they induce extra flow loss and inlet distortions. In this paper, the detailed flow characteristics inside the radial inlet chamber of an industrial centrifugal compressor have been numerically investigated for flow control and performance improvement. First, the numerical results are validated against the experimental data, and flow conditions inside the inlet chambers with different structures are compared. They indicate that, in the non-guide vane scheme, sudden expansions, tangential flows and flow separations in the spiral and annular convergent channels are the major causes of flow loss and distortions, while using guide vanes could introduce additional flow impacts, separations and wakes. Based on the flow analysis, structure improvements have been carried out on the radial inlet chamber, and an average increase of 4.97% has been achieved in the inlet chamber efficiencies over different operating conditions. However, the results further reveal that the increases in the performance and overall flow uniformity just in the radial inlet chamber do not necessarily mean a performance improvement in the downstream components, and the distribution of the positive tangential velocity at the impeller inlet might be a more essential factor for the efficiency of the whole compressor.
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Mevissen, Frank, and Michele Meo. "A Review of NDT/Structural Health Monitoring Techniques for Hot Gas Components in Gas Turbines." Sensors 19, no. 3 (February 9, 2019): 711. http://dx.doi.org/10.3390/s19030711.
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The need for non-destructive testing/structural health monitoring (SHM) is becoming increasingly important for gas turbine manufacturers. Incipient cracks have to be detected before catastrophic events occur. With respect to condition-based maintenance, the complex and expensive parts should be used as long as their performance or integrity is not compromised. In this study, the main failure modes of turbines are reported. In particular, we focus on the turbine blades, turbine vanes and the transition ducts of the combustion chambers. The existing monitoring techniques for these components, with their own particular advantages and disadvantages, are summarised in this review. In addition to the vibrational approach, tip timing technology is the most used technique for blade monitoring. Several sensor types are appropriate for the extreme conditions in a gas turbine, but besides tip timing, other technologies are also very promising for future NDT/SHM applications. For static parts, like turbine vanes and the transition ducts of the combustion chambers, different monitoring possibilities are identified and discussed.
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Han, Fenghui, Zhe Wang, Yijun Mao, Jiajian Tan, and Wenhua Li. "Experimental and numerical studies on the influence of inlet guide vanes of centrifugal compressor on the flow field characteristics of inlet chamber." Advances in Mechanical Engineering 12, no. 11 (November 2020): 168781402097490. http://dx.doi.org/10.1177/1687814020974909.
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Inlet chambers (IC) are the typical upstream component of centrifugal compressors, and inlet guide vanes in the IC have a great impact on its internal flow and aerodynamic loss, which will significantly influence the performance of the downstream compressor stages. In this paper, an experimental study was carried out on the flow characteristics inside a radial IC of an industrial centrifugal compressor, including five testing sections and 968 measuring points for two schemes with and without guide vanes. Detailed distributions of flow parameters on each section were obtained as well as the overall performance of the radial IC, and the causes of the flow loss inside the IC and the non-uniformity of flow parameters at the outlet section were investigated. Besides, numerical simulations were performed to further analyze the flow characteristics inside the radial IC. The experimental and numerical results indicate that, in the scheme without guide vanes, sudden expansions in the spiral channel and flow separations in the annular convergence channel are the major sources of flow loss and distortions generated in the radial IC; while in the scheme with guide vanes, the flow impacts, separations and wakes caused by the inappropriate design of guide vanes are the main reasons for the flow loss of the IC itself and the uneven flow distributions at the IC outlet.
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Shaikh, Faisal, and Budimir Rosic. "Unsteady phenomena at the combustor-turbine interface." Journal of the Global Power and Propulsion Society 5 (November 23, 2021): 202–15. http://dx.doi.org/10.33737/jgpps/143042.
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The combustor-turbine interface in a gas turbine is characterised by complex, highly unsteady flows. In a combined experimental and large eddy simulation (LES) study including realistic combustor geometry, the standard model of secondary flows in the nozzle guide vanes (NGV) is found to be oversimplified. A swirl core is created in the combustion chamber which convects into the first vane passages. Four main consequences of this are identified: variation in vane loading; unsteady heat transfer on vane surfaces; unsteadiness at the leading edge horseshoe vortex, and variation in the position of the passage vortex. These phenomena occur at relatively low frequencies, from 50–300 Hz. It seems likely that these unsteady phenomena result in non-optimal film cooling, and that by reducing unsteadiness designs with greater cooling efficiency could be achieved. Measurements were performed in a high speed test facility modelling a large industrial gas turbine with can combustors, including nozzle guide vanes and combustion chambers. Vane surfaces and endwalls of a nozzle guide vane were instrumented with 384 high speed thin film heat flux gauges, to measure unsteady heat transfer. The high resolution of measurements was such to allow direct visualisation in time of large scale turbulent structures over the endwalls and vane surfaces. A matching LES simulation was carried out in a domain matching experimental conditions including upstream swirl generators and transition duct. Data reduction allowed time-varying LES data to be recorded for several cycles of the unsteady phenomena observed. The combination of LES and experimental data allows physical explanation and visualisation of flow events.
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Sadykova, Samal, Abay Dostiyarov, Mikhail Zhumagulov, and Nurlan Kartjanov. "The influence of turbulence on the efficiency and reliability of combustion chamber of the gas turbine." Thermal Science, no. 00 (2021): 64. http://dx.doi.org/10.2298/tsci200831064s.
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The article presents the research results related to the influence of turbulence on the efficiency of the combustion chamber of gas turbine. An artificial increase in the intensity of turbulence is considered as a way to improve the formation of a fuel-air mixture. Turbulent flow is formed due to the installation of guide swirlers at the entrance to the device for creating a fuel-air mixture - a micro module. The angle of rotation of the swirler blades is selected. Theoretical research, mathematical software modeling, as well as an aerodynamic experiment have been carried out. As a result, design solutions are provided that significantly increase the efficiency and reliability of the gas turbine combustion chamber. In the course of the study, guide vanes were selected, and their design was established. The recommended swing angle of the swirler guide vanes is 40?. The recommended depth of the fuel injector inside the chamber is 1.0 gauge.
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Zhang, Huiyan, Fan Meng, Lei Cao, Yanjun Li, and Xinkun Wang. "The Influence of a Pumping Chamber on Hydraulic Losses in a Mixed-Flow Pump." Processes 10, no. 2 (February 19, 2022): 407. http://dx.doi.org/10.3390/pr10020407.
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In this study, entropy generation theory based on computational fluid dynamics (CFD) is used to study the influence of a pumping chamber type (guide vane and volute scheme) on the spatial distribution of hydraulic loss in a mixed-flow pump. The CFD data of the mixed-flow pump with a volute is validated by external characteristic test data under Q = 561.4–1598.6 m3/h. The results show that the efficiency and the head of the guide vanes scheme are lower under Q = 800–1200 m3/h, which resulted from a higher total entropy production (TEP) in the pumping chamber and outlet pipe. The high total entropy production rate (TEPR) inside the guide vanes can be found near the leading edge of the hub side and trailing edge of the rim side due to flow separation, which reduces the recovery efficiency of kinetic energy of the guide vanes. The high TEPR inside outlet pipe can be seen near the inlet, caused by back flow. However, the efficiency and head of the volute scheme are lower, under Q = 1200–1600 m3/h, owing to the fact that the volute cannot effectively convert kinetic energy into pressure energy and thus the high TEPR can be found near outlet of volute and inlet of outlet pipe. These results can provide useful suggestions to the matching optimization of the impeller and pumping chamber in a mixed-flow pump.
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Kotlov, Andrey, Leonid Kuznetsov, and Boris Hrustalev. "Investigation of the influence of the number of vanes on the performance of a rotary vane compressor." MATEC Web of Conferences 245 (2018): 04008. http://dx.doi.org/10.1051/matecconf/201824504008.
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We developed a mathematical model for determining the parameters of mass transfer in the compressor chambers during the processes of compression and discharge. The mass flow rates through the end and radial gaps were determined. Also we analyzed the processes of mass transfer in a clamped volume. We investigated the influence of the number of vanes on the compressor efficiency, taking into account changes in the compressor geometric parameters. We established that overflows through the end surfaces of rotor mainly affect the compressor performance. In order to reduce overflows during the period of discharge, it was proposed to increase the angle of closure of the discharge window at a fixed angle of its opening. The mathematical model allows one to make recommendations on the choice of the optimal number of vanes for a particular design.
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Povarova, K. B., and O. A. Skachkov. "Preparation, Structure, and Properties of Ni3Al and NiAl Light Powder Alloys for Aerospace." Materials Science Forum 534-536 (January 2007): 1585–88. http://dx.doi.org/10.4028/www.scientific.net/msf.534-536.1585.
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New light super-heat-resistant powder Ni3Al and NiAl-based alloys (of the Ni-Al-Mo-B, Ni-Al-Fe-La, and Ni-Al-Y2O3 systems), as well as a new technology for preparing and processing them have been developed. The density of the alloys was 7.3-7.5 and ~6 g/cm 3, respectively. The Ni3Al sheets were used to prepare shields for combustion chambers in gas-turbine engines by roomtemperature deformation; the shields are intended for the long-term operation at 1100-1200°C and for the short-term use at 1300°C. The activated NiAl powders alloyed with Fe+La were used to produce sintered complex-shape articles, such as combustion stabilizers in a jet unit of combustion chamber of the gas-turbine installation, heat sources, etc. capable of operating at t≤1500°C under low mechanical stresses. At 1100, 1300, and 1500°C, the 100-h strength of the heat-resistant NiAl- (2-7.5) vol. % Y2O3 alloys subjected to directional recrystallization is 70, 35 and ≥10 MPa, respectively. The vanes, in which the length of recrystallized grain is smaller than the vane length by a factor of 1.5-2, were manufactured from these alloys.
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Bao, Ming, and Jiming Lin. "Numerical simulation of combustion distribution in a gas burner." E3S Web of Conferences 236 (2021): 01002. http://dx.doi.org/10.1051/e3sconf/202123601002.
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The combustion effect of natural gas-air mixed combustion is optimised through an effective and rational design of the burner structure, thereby reducing the emission of atmospheric pollutants and achieving energy saving and emission reduction. This paper starts from the geometric model of the burner and uses Computational Fluid Dynamics (CFD) technology to numerically simulate the combustion distribution in the burner, which results in the combustion distribution of the burner after optimising the structure. The guiding effect of the blower guide vanes on the airflow is weak, and the back pressure effect of the guide vanes mounting body is significant, which reduces the primary air volume and prolongs the combustion history in the central region of the flame; The temperature field is evenly distributed and the combustion is well distributed; CH4 and CO in the furnace chamber are basically burned out and the NO concentration in the furnace chamber is about 800 ppm, which basically meets the emission standard and the combustion effect is good. This paper has certain guiding significance for the study of burner structure.
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He, Qilian, Xingxing Huang, Mengqi Yang, Haixia Yang, Huili Bi, and Zhengwei Wang. "Fluid–Structure Coupling Analysis of the Stationary Structures of a Prototype Pump Turbine during Load Rejection." Energies 15, no. 10 (May 20, 2022): 3764. http://dx.doi.org/10.3390/en15103764.
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During the load rejection transient process of the prototype pump turbine units, the pressure fluctuations of the entire flow passage change drastically due to the rapid closing of guide vanes. The extremely unsteady pressure distribution in the flow domains including the crown chamber and the band chamber may cause a strong vibration on the stationary structures of the unit and result in large dynamic stress on the head cover, stay ring and bottom ring. In this paper, the numerical fluid dynamic analysis of the entire flow passage of a reversible prototype pump turbine during load rejection was performed. The flow characteristics in the runner passage, crown chamber, band chamber, seal labyrinths and balance tubes are analysed. The corresponding unsteady flow-induced dynamic behaviour of the head cover, stay vanes and bottom ring was investigated in detail. The analysed results show that the total deformation of the inner edge of the head cover closed to the main shaft is larger than that of other stationary structures of the unit during the load rejection. The maximum stress of the stay ring is larger than that of the head cover and the bottom ring and the maximum equivalent stress is located at the fillet of the stay vane trailing edge. The fluid–structure coupling calculation method and the analysed results can provide guidance for the design of stationary components of hydraulic machinery such as pump turbines, Francis turbines and centrifugal pumps with different heads.
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Parra-Santos, Teresa, J. R. Pérez-Domínguez, R. Z. Szasz, and F. Castro-Ruiz. "An isothermal analysis of curved-vane and flat-vane swirlers for burners." Engineering Computations 32, no. 3 (May 5, 2015): 668–86. http://dx.doi.org/10.1108/ec-06-2013-0149.
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Purpose – One current trend in burner technology is to obtain high efficiency while keeping low levels of NOx emissions. A swirling flow in combustion ensures a fixed position of a compact flame. Therefore, it is necessary to design efficient swirlers. Flow patterns are simulated for the different swirl devices proposed in this work. Two axial-swirlers are studied: one based on curve-vanes consisting of a straight line with an arc of a circle as the trailing edge and the other is the common flat-vanes. The purpose of this paper is to assess the accuracy of different swirl generators using a well-known benchmark test case. Design/methodology/approach – This work deals with modelling the swirler using two approaches: the general purpose Computational fluid dynamics (CFD) solver Ansys-Fluent® and the suite of libraries OpenFOAM® to solve the Reynolds Averaged Navier Stokes equations, showing there is a slight deviation between both approaches. Their performance involves analyzing not only the Swirl number but also the size of the recirculation zones in the test chamber. A subsequent process on the flow patterns was carried out to establish the intensity of segregation which provides insight into the quality of mixing. Findings – CFD models are feasible tools to predict flow features. It was found that numerical results tend to reduce the inner recirculation zone (IRZ) radial size. Further, an increase of the swirl number involves larger IRZ and a smaller outer recirculation zone (ORZ). The curved swirler displays a better axi-symmetric behaviour than flat vanes. There is weak influence of the chord vanes on the swirl number. The number of vanes is a compromise of head loses and guidance of the flow. Originality/value – The paper offers two different approaches to solve turbulent swirling flows. One based in a general contrasted commercial tool and other using open source code. Both models show similar performance. An innovative set up for an axial swirler different from the conventional flat vanes was proposed.
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Quan, Hui, Yi Chai, Rennian Li, and Jianhui Guo. "Numerical simulation and experiment for study on internal flow pattern of vortex pump." Engineering Computations 36, no. 5 (June 10, 2019): 1579–96. http://dx.doi.org/10.1108/ec-09-2018-0420.
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Purpose The special structure of the vortex pump contributes to its complex internal flow pattern. A type of horizontal 150WX-200-20 vortex pump is taken as a research subject to deeply study the progression and distribution of flow pattern in its channel. To explain the mechanism of flow in this pump, numerical analysis of the whole flow and experiment have been conducted. Design/methodology/approach The authors studied and analyzed the distribution and evolution of flow pattern under different flow, such as circulating-flow, through-flow and other forms. Finally, a model of flow pattern in the vortex pump has been built, which has more perfectly fit the reality. Findings They are through-flow affected by circulating-flow, main and subsidiary circulating-flow, vortices between vanes and other vortices (or liquid impingement) in volute. Entering the pump, part of the flow stays in vanes and turn into vortices while the other goes into the front chamber. The flow that runs into the front chamber will be divided into two parts. One part will be collected by viscosity into a vortex rope when it passing through the interface between the impeller and the vaneless chamber, which closely relates to the circulating-flow, and the rest directly goes out of the field through the diffuser. Besides, a fraction of circulating-flow joins the through-flow when it goes through the section V and leaves the pump. Originality/value The research results build a theoretical foundation for working out the flow mechanism of the vortex pump, improving its efficiency and optimizing its hydraulic design.
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Придорожный, Роман Петрович, Александр Викторович Шереметьев, and Анатолий Павлович Зиньковский. "ВЛИЯНИЕ ПОЛЗУЧЕСТИ МАТЕРИАЛА НА РАБОТОСПОСОБНОСТЬ ЛОПАТОК СОПЛОВОГО АППАРАТА ТУРБИНЫ ВЫСОКОГО ДАВЛЕНИЯ." Aerospace technic and technology, no. 7 (August 31, 2020): 41–46. http://dx.doi.org/10.32620/aktt.2020.7.06.
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The creation of aircraft gas turbine engines that meet modern requirements for the resource, especially its hot part, requires not only more advanced design methods but also an analysis of operability and damageability during the resource to find reserves aimed at improving reliability. One of the most complex and heat-stressed components of a modern gas turbine engine is the nozzle vanes of a high-pressure turbine, directly perceiving the high temperature of the gas at the exit of the combustion chamber and having an advanced convection-film cooling system. The service life nozzle vanes of modern aviation gas turbine engines can be tens of thousands of hours. At the same time, the maximum operating mode can reach only a few hundred hours. It is believed that damage to nozzle vanes on an engine occurs mainly in hot climatic zones. Nevertheless, as the analysis of computational studies for modern aviation gas turbine engines shows, such statements are erroneous. The direct consequence of the action of elevated temperatures and high thermal stresses is the creep of the material. A computational study of the effect of creep of the material of the nozzle vanes of a high-pressure turbine under various operating conditions of the engine on their operability was carried. It is shown that with increasing flight altitude the working temperature of the nozzle vane begins to increase, and creep processes are accelerated for all climatic zones of operation. Since with increasing flight altitude, the temperature difference for different climatic zones gradually decreases, at high altitudes, where the temperature in different climatic zones differs slightly, stress relaxation processes proceed identically. In this case, with an increase in temperature, creep processes proceed faster, and the stress level to which stress relaxation occurs becomes lower. Thus, with increasing flight altitude, damage in cold conditions approaches that under normal and hot conditions, and at high altitudes, it can even be higher. The regularities of the influence of climatic conditions and flight altitude on the strength of the nozzle vanes of high-pressure turbines and their operability are established, based on which the need to take into account the operating time of the engine in various climatic conditions when determining the service life of nozzle vanes is shown.
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Mazalov, P. B., D. I. Suhov, E. A. Sulyanova, and I. S. Mazalov. "HEAT-RESISTANT COBALT-BASED ALLOYS." Aviation Materials and Technologies, no. 3 (2021): 3–10. http://dx.doi.org/10.18577/2713-0193-2021-0-3-3-10.
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Cobalt-based alloys are widely used for manufacturing of various components of gas turbine engines and gas turbines such as vanes and combustion chambers both in wrought state and as cast parts. They have been designed for improving the heat resistance due to solid solution and carbide-strengthening mechanisms. In order to obtain satisfactory oxidation resistance and hot corrosion resistance cobalt-based alloys are doped with sufficient amount of chromium (above 15 % wt.). Recently additive manufacturing has started to use cobalt-based alloys. The paper considers the features of the structure of high-temperature cobalt-based alloys and their application in various branches of industry.
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Weisweiler, Hardy, Jasmina Kojouharova, and Roland Dückershoff. "Design of short low speed Göttingen type wind tunnel: CFD simulation." MATEC Web of Conferences 145 (2018): 03015. http://dx.doi.org/10.1051/matecconf/201814503015.
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The paper is focused on design simulations by the means of commercial software for a low speed circuit wind tunnel with an open test section, recently built at the Department of Mechanical Engineering, Mechatronics and Materials Technology at THM University of Applied Sciences in Friedberg. The proposed wind tunnel has a test section with cross sectional area of 1 X 1 m2 and a length of 1.6 m. The maximum achievable speed is about 50 m/s with empty test section. The simulation had the target to propose and to verify various geometries - test chamber, tunnel contraction, diffuser etc. as well the tunnel corner including the vanes. In addition, the influence of the vanes number and their shape on the ventilator power needed and the flow velocity uniformity as well, have been subjects of the investigation. Also the ventilator type (rotational segment) impact on the flow pattern within the operational area has been scrutinized.
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Zhao, Weiqiang, Xingxing Huang, Mengqi Yang, Haixia Yang, Huili Bi, Qilian He, and Zhengwei Wang. "Flow-Induced Dynamic Behavior of Head-Cover Bolts in a Prototype Pump-Turbine during Load Rejection." Machines 10, no. 12 (November 28, 2022): 1130. http://dx.doi.org/10.3390/machines10121130.
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In order to ensure stable grid operatiFon and improve power quality, active or passive load rejection of pumped storage power stations (PSPS) inevitably occurs from time to time. The rapid closing of the guide vanes will cause drastic changes in pressure pulsations in the flow channel of the pump-turbine (PT) unit. The high-level pressure pulsations during load rejection transfer to the entire flow passage of the PT unit and generate strong vibrations on the head-cover and the connecting bolts. In this study, the 1D/3D joint simulation of the pipeline in a pumped storage power station and the turbine flow channels including the flow domains of the runner, crown chamber, band chamber, upper and lower labyrinths and pressure balance tubes is carried out first. Then, by applying the calculated pressure loads on the head-cover, stay vanes and bottom ring of the PT unit, the flow-induced dynamic behavior of the structures including the head-cover bolts is analyzed in detail. The results demonstrate that pressure loads on head-cover bolts change dramatically during the load rejection process. The flow-induced deformation of the inner head-cover during the load rejection is larger than that of other structures, and the flow-induced displacement and stress of different head-cover bolts are not uniform. The achieved conclusions in this study can be a useful reference for the design and operation of head-cover bolts for other PT units and high-head Francis turbine units.
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Ogawa, T., M. Takao, M. M. A. Alam, S. Okuhara, and Y. Kinoue. "A study of counter-rotating impulse turbine for wave energy conversion-effect of middle vane thickness on the performance-." Journal of Physics: Conference Series 2217, no. 1 (April 1, 2022): 012073. http://dx.doi.org/10.1088/1742-6596/2217/1/012073.
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Abstract In an oscillating water column (OWC) based wave energy device, a water column that oscillates due to the sea wave motion generates a bi-directional airflow in an air chamber, and finally, the bi-directional airflow driven air turbine converts the pneumatic energy into mechanical energy. The counter-rotating impulse turbine for bi-directional airflow has been proposed by M. E. McCormick of the United States Naval Academy in 1978. In a previous study, the authors investigated the effect of the turbine geometry on the performance of a counter-rotating impulse turbine for bi-directional airflow, and it was clarified that the efficiency of the turbine is higher than an impulse turbine with a single rotor for bi-directional airflow in a range of high flow coefficient. Moreover, this impulse turbine has a disadvantage that the efficiency in a range of low flow coefficient is remarkably low due to the deterioration of the flow between the two rotors. In this study, in order to make the counter-rotating impulse turbine practically compatible, the thickness of the middle vanes installed between the two rotors was changed, and the effect of the thickness on the turbine performance was investigated by the computational fluid dynamics (CFD) analysis. As a result, it was found that the efficiency of the counter-rotating impulse turbine with middle vanes increases as the thickness of the middle vanes decreased.
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Chai, Junsheng, Zhenyu Wang, Xuanling Zhao, and Chunhua Wang. "Multiobjective Optimization of Turbine Coolant Collection/Distribution Plenum Based on the Surrogate Model." International Journal of Aerospace Engineering 2021 (August 31, 2021): 1–12. http://dx.doi.org/10.1155/2021/2033711.
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The turbine coolant collection/distribution chamber, as an important component of the secondary air system, undertakes the task of collecting and distributing coolant for guide vanes. To improve the outflow uniformity and reduce the flow loss, a multiobjective optimization method is developed for geometric parameters of turbine chamber. Numerical experiments were designed by Latin hypercube sampling and solved by the CFD method. Based on these data sampling, least square support vector machine (LS-SVM) was used for the surrogate model, and a kind of chaotic optimization algorithms was used for searching for the Pareto solution set. The results show that the streamline change in the optimized chamber is smoother, and the jet impingement effect of the coolant from the inlet tube was significantly weakened. At the condition that each goal has the weight of 0.5, the optimized discharge coefficient increases by 26%, and the outflow nonuniformity decreases by 79% compared with reference structure.
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Li, Jiahu, Chi Ma, Shaohua Wu, and Jiaxing Li. "Thermal Calculation and Analysis of 9FA Type Gas Turbine Basic Conditions." Journal of Physics: Conference Series 2433, no. 1 (February 1, 2023): 012029. http://dx.doi.org/10.1088/1742-6596/2433/1/012029.
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Abstract This paper takes GE’s PG9351FA gas turbine as the research object. From the perspective of energy conservation and mass balance, the compressor, the combustion chamber and the turbine are modeled separately, and then the models are coupled. Key parameters such as fuel, air and gas properties, unit fuel volume, cooling air volume, cooling air volume of the first stage vanes, equivalent turbine front temperature, and compressor efficiency are obtained through the model. The research results meet the engineering error requirements and have certain reference significance for the thermal design of gas turbines.
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Alduqri, Y. A., and Md Nor Musa. "Theoretical Study of a Novel Four-Chamber Rotary Compressor: Design and Thermodynamic Analysis." Applied Mechanics and Materials 819 (January 2016): 46–57. http://dx.doi.org/10.4028/www.scientific.net/amm.819.46.
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A novel four-chamber rotary compressor (FCRC) is being developed for a refrigerator and an air-conditioning system. The novelty lies in the usage of three rotating sleeves and two oppositely installed vanes each has one end fixed to an outer sleeve and the other end to a rotor, respectively. In this paper, the swept volume, the delivered pressure, the work and the power of the FCRC are formulated and analyzed. The compressor configuration and thermodynamic analysis are based on the 174 cc swept volume with R134a as the compressed gas. Considering the encouraging results, added by design simplicity of mainly cylindrical shaped components, the proposed FCRC is reckoned to be very suitable to be used for air-conditioning and refrigeration applications.
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Andreev, Mikhail, Yuriy Zhuravlev, Yuriy Lukyanov, and Leonid Perminov. "Autonomous Power Station Based on Rotary-Vane Engine with an External Supply of Heat." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 2 (August 8, 2015): 97. http://dx.doi.org/10.17770/etr2013vol2.842.
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Rotary-vane engine (RVE) with an external supply of heat is an aggregate consisting of two modules with a common output shaft, the heating device (heater) of working medium and the cooling device (cooler) of working medium, which connected with inlet and outlet ports of modules by system of pipeworks. Each module has two rotors with two vanes on each. Between the corresponding plane surfaces of the four vanes four working volumes are formed wherein thermodynamic cycle steps: ingress, compressing, heat intake, expansion stroke, discharge, outward heat transmission are going simultaneously. The angular displacement of modules relative to one another occurs pumping the working medium through the heater and cooler, which allows the conversion of thermal energy into mechanical work. Design features of the RVE with an external supply of heat allows create a closed gas-vapor cycle. The main specified advantages of the RVE with an external supply of heat are: fewer noxious emissions, multifuel capability, high motor potential (service life). Different problems of creation external combustion engines such as structural complexity of construction units, absence of adequate mathematical model of designed RVE with an external supply of heat are also pointed. The construction of the RVE with an external supply of heat developed in Pskov Polytechnic Institute (now the Pskov State University), the operation concept of the engine, the physical processes in the chamber modules RVE with an external supply of heat during each step and the mathematical model describing the physical processes proceeding in chamber RVE with an external supply of heat modules are considered.
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Zeng, Yun, Bowen Huang, Daoxin Qin, Sizhu Zhou, and Meiqiu Li. "Numerical and Experiment Investigation on Novel Guide Vane Structures of Turbo Air Classifier." Processes 10, no. 5 (April 25, 2022): 844. http://dx.doi.org/10.3390/pr10050844.
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In this paper, three types of air guide vanes are designed: direct-type, L-type, and logarithmic spiral type, respectively. ANSYS-FLUENT 20.0 is used to numerically simulate the internal flow field of turbo air classifier by novel different structures. The numerical results show that the guide vane structures have a good effect on the flow field stability of the annular function zone in the classifying chamber. The distribution of tangential velocity and radial velocity verified the logarithmic spiral guide vane, and makes the airflow flow along the rotor cage circumferentially uniformly. In addition, the turbulent dissipation rate and energy loss decreases in the rotor cage region, which also shows that the guide vane is beneficial to improve classification performance. The tromp curve of the numerical simulation shows that the logarithmic spiral guide vane reduced the cutting size by 6.3% and 23.7% at two different process parameters, and is obviously better than other guide vane structures in improving the classification sharpness index (K). Finally, the reliability of numerical simulation is verified by material experiment. The research results have certain theoretical significance and guidance for the structural design of the guide vanes of the turbo air classifier.
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Zeng, Yun, Bowen Huang, Daoxin Qin, Sizhu Zhou, and Meiqiu Li. "Numerical and Experiment Investigation on Novel Guide Vane Structures of Turbo Air Classifier." Processes 10, no. 5 (April 25, 2022): 844. http://dx.doi.org/10.3390/pr10050844.
Full textAbstract:
In this paper, three types of air guide vanes are designed: direct-type, L-type, and logarithmic spiral type, respectively. ANSYS-FLUENT 20.0 is used to numerically simulate the internal flow field of turbo air classifier by novel different structures. The numerical results show that the guide vane structures have a good effect on the flow field stability of the annular function zone in the classifying chamber. The distribution of tangential velocity and radial velocity verified the logarithmic spiral guide vane, and makes the airflow flow along the rotor cage circumferentially uniformly. In addition, the turbulent dissipation rate and energy loss decreases in the rotor cage region, which also shows that the guide vane is beneficial to improve classification performance. The tromp curve of the numerical simulation shows that the logarithmic spiral guide vane reduced the cutting size by 6.3% and 23.7% at two different process parameters, and is obviously better than other guide vane structures in improving the classification sharpness index (K). Finally, the reliability of numerical simulation is verified by material experiment. The research results have certain theoretical significance and guidance for the structural design of the guide vanes of the turbo air classifier.
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Hamid, Mohd Fadzli, Mohamad Yusof Idroas, Shukriwani Sa’ad, Teoh Yew Heng, Sharzali Che Mat, Zainal Alimuddin Zainal Alauddin, Khairul Akmal Shamsuddin, Raa Khimi Shuib, and Muhammad Khalil Abdullah. "Numerical Investigation of Fluid Flow and In-Cylinder Air Flow Characteristics for Higher Viscosity Fuel Applications." Processes 8, no. 4 (April 8, 2020): 439. http://dx.doi.org/10.3390/pr8040439.
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Generally, the compression ignition (CI) engine that runs with emulsified biofuel (EB) or higher viscosity fuel experiences inferior performance and a higher emission compared to petro diesel engines. The modification is necessary to standard engine level in order to realize its application. This paper proposes a guide vane design (GVD), which needs to be installed in the intake manifold, is incorporated with shallow depth re-entrance combustion chamber (SCC) pistons. This will organize and develop proper in-cylinder airflow to promote better diffusion, evaporation and combustion processes. The model of GVD and SCC piston was designed using SolidWorks 2017; while ANSYS Fluent version 15 was utilized to run a 3D analysis of the cold flow IC engine. In this research, seven designs of GVD with the number of vanes varied from two to eight vanes (V2–V8) are used. The four-vane model (V4) has shown an excellent turbulent flow as well as swirl, tumble and cross tumble ratios in the fuel-injected region compared to other designs. This is indispensable to break up heavier fuel molecules of EB to mix with the air that will eventually improve engine performance.
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Baltrėnas, Pranas, and Alvydas Zagorskis. "INVESTIGATION OF CLEANING EFFICIENCY OF A BIOFILTER WITH AN AERATION CHAMBER/VALYMO BIOFILTRU SU AERACINE KAMERA EFEKTYVUMO TYRIMAI/ИССЛЕДОВАНИЕ ЭФФЕКТИВНОСТИ БИОФИЛЬТРА С АЭРАЦИОННОЙ КАМЕРОЙ." JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT 17, no. 1 (March 31, 2009): 12–19. http://dx.doi.org/10.3846/1648-6897.2009.17.12-19.
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The investigation was carried out using a biological air‐treatment device, i.e. a biofilter with an aeration chamber filled with water saturated with biogenic elements. To accelerate the absorption of organic compounds, air polluted with volatile organic compounds is directed to a water reservoir installed in the lower part of the filter where organic compounds are destructed. In the process of aeration, microorganisms propagate in the chamber, degrading part of pollutants to harmless products, carbon dioxide and water. Since all hydrocarbons are water‐soluble, the aeration chamber is the first phase in a hydrocarbon degradation process. Application of such a polluted air‐feeding model improves the sorption qualities of a charge. When relative air humidity reaches 100%, water‐drops evenly distribute over the entire surface area of the charge and improve the activity of microorganisms. Having passed through the aeration chamber, polluted air is filtered via charges of a different origin, composed of zeolite, foam, wood chips or their mixtures. The carried out experiment shows that the best charge filtering capacity is achieved when supplying air polluted with acetone at the rate of 0.1 m/s. At the initial pollutant concentration of 115 mg/m3 the biofilter treatment efficiency reached 96%. The aeration chamber installed in the biofilter increases both microbiological activity of the charge and air treatment efficiency. Santrauka Tyrimai atlikti naudojant biologinį oro valymo įrenginį – biofiltrą su aeracine kamera, pripildyta biogeninių elementų prisotinto vandens. Siekiant pagreitinti organinių junginių absorbciją lakiaisiais organiniais junginiais, užterštas oras nukreipiamas į filtro apatinėje dalyje įrengtą vandens talpyklą, kurioje vyksta organinių junginių destrukcija. Aeracijos proceso metu kameroje dauginasi mikroorganizmai. Jie suskaido dalį teršalų iki nekenksmingų produktų – anglies dvideginio ir vandens. Visi angliavandeniliai tirpūs vandenyje, todėl aeracinė kamera yra pirminis angliavandenilių skilimo proceso etapas. Taikant tokį užteršto oro tiekimo į įrenginį modelį pagerinamos įkrovos sorbcinės savybės. Santykinei oro drėgmei pakilus iki 100 %, vandens lašeliai tolygiai pasiskirsto per visą įkrovos paviršiaus plotą ir pagerina mikroorganizmų aktyvumą. Pratekėjęs aeracinę kamerą užterštas oras filtruojamas pro skirtingos kilmės įkrovas, sudarytas iš ceolito, porolono, medienos drožlių ir jų mišinių. Atlikus eksperimentinius tyrimus nustatyta, kad geriausiai įkrova filtravo 0,1 m/s greičiu į įrenginį tiekiamą acetonu užterštą orą. Esant pradinei šio teršalo koncentracijai 115 mg/m3 , valymo biofiltru efektyvumas siekė 96 %. Taigi biofiltre įrengta aeracinė kamera padidina įkrovos mikrobiologinį aktyvumą ir užteršto oro valymo efektyvumą. Резюме При выполнении экспериментальных исследований использовалось биологическое устройство для очистки воздуха – биофильтр с аэрационной камерой, заполненной водой и насыщаемой биогенными элементами. Для того, чтобы ускорить процессы абсорбции органических соединений, воздух, загрязненный летучими органическими соединениями, направлялся в резервуар с водой, установленный в низкой части фильтра, в котором органические соединения разрушались. В процессе аэрации в камере размножаются микроорганизмы, которые разрушают часть загрязнителей до безопасных продуктов: углекислого газа и воды. Так как все углеводороды растворимы в воде, в аэрационной камере происходит первоначальный процесс деградации углеводорода. При такой модели подачи загрязненного воздуха в устройство улучшаются сорбционные свойства загрузки. Когда относительная влажность воздуха достигает 100%, капли воды равномерно распределяются по всей площади поверхности загрузки и улучшают деятельность микроорганизмов. Пройдя через аэрационную камеру, загрязненный воздух фильтруется через загрузку различного происхождения, составленную из цеолита, поролона, щепы или их смесей. Эксперимент показал, что загрузка лучше всего фильтровала загрязненный ацетоном воздух, подаваемый в устройство со скоростью 0,1 м/сек. При начальной концентрации загрязнителя, равной 115 мг/м3 , эффективность биофильтра достигала 96%. Таким образом, установленная в биофильтре аэрационная камера увеличивает как микробиологическую активность загрузки, так и эффективность очищения воздуха.
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Desmico Ekta W, Muhammad, and Abrar Ridwan. "STUDI KERUSAKAN HIGH PRESSURE TURBINE VANE PESAWAT ATR72-500 WINGS AIR DI BANDARA SULTAN SYARIF KASIIM II PEKANBARU." Jurnal Surya Teknika 7, no. 1 (December 13, 2020): 104–10. http://dx.doi.org/10.37859/jst.v7i1.2357.
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The aircraft can fly as there is a thrust from the engine that causes the aircraft to have speed. The components of the aircraft engines are compressor, combustion chamber, turbine and propeller. High pressure turbine vanes is a component in the Hot section or turbine section that serves to direct the hot gas flow from the combustion chamber to the turbine. The purpose to be achieved in this research is to analyze and find out the cause of high pressure turbine vane damage and know the gas engine efficiency PW127. Cause of damage due to treatment not done according to the schedule until the phenomenon of overtemperature after combustion chamber and the content of impurities in the water laundering results. After the Brayton cycle calculation is obtained the temperature value of the turbine entry 1563oC (1836 K). These results exceed the turbine inlet temperature according to manual maintenance engine. Based on laboratory test, the content of 250 mg/m2 sulfur and 1800 mg/m2 chloride is obtained. This content causes damage by erosion or corrosion of high pressure turbine vane components. The value of gas efficiency is 42% according to the outside Air tempetarure. The thermal efficiency of gases will increase with increasing temperature conditions.
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Thakker, A., T. S. Dhanasekaran, M. Takao, and T. Setoguchi. "Effects of Compressibility on the Performance of a Wave-Energy Conversion Device with an Impulse Turbine Using a Numerical Simulation Technique." International Journal of Rotating Machinery 9, no. 6 (2003): 443–50. http://dx.doi.org/10.1155/s1023621x03000435.
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This article presents work carried out to predict the behavior of a 0.6 m impulse turbine with fixed guide vanes as compared with that of a 0.6 hub-to-tip ratio turbine under real sea conditions. In order to predict the true performance of the actual oscillating water column (OWC), the numerical technique was fine-tuned by incorporating the compressibility effect. Water surface elevation versus time history was used as the input data for this purpose. The effect of compressibility inside the air chamber and the turbine's performance under unsteady and irregular flow conditions were analyzed numerically. Considering the quasi-steady assumptions, the unidirectional steady-flow experimental data was used to simulate the turbines characteristics under irregular unsteady flow conditions. The results showed that the performance of this type of turbine is quite stable and that the efficiency of the air chamber and the mean conversion efficiency are reduced by around 8% and 5%, respectively, as a result of the compressibility inside the air chamber. The mean efficiencies of the OWC device and the impulse turbine were predicted for 1 month, based on the Irish wave climate, and it was found that the total time period of wave data used is one of the important factors in the simulation technique.
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Ebrahimi, M., and S. A. Jazayeri. "A Theoretical Study of the Internal Forces in a Hydraulic Vane Pump with Hypertrochoid Curve in the Inner Surface of its Stator." Advanced Materials Research 463-464 (February 2012): 301–4. http://dx.doi.org/10.4028/www.scientific.net/amr.463-464.301.
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In the latest our works, Performance of a fixed displacement- hydraulic balance vane pump, theoretically and practically was studied by application of the basic hypertrochoid curve in the inner surface of its stator. Also the effect of the inertia force of the vanes on the performance of the pump with this curve was studied. This study presents a theoretical analysis of the internal pressure distribution in the pump, and of the resulting forces and torques applied to its components. This analysis is essential to the study of the pump dynamics and control, the pump design, and selection of the pump bearings. These forces are shown to be a function of the line pressure, the shaft rotational speed, the fluid bulk modulus, the fluid viscosity, and the design geometry. These forces are composed of two components: a continuous component due to the exposure of chambers to the line port, and an intermittent component due to a hydraulic lock phenomenon.
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Crosa, G., F. Pittaluga, A. Trucco, F. Beltrami, A. Torelli, and F. Traverso. "Heavy-Duty Gas Turbine Plant Aerothermodynamic Simulation Using Simulink." Journal of Engineering for Gas Turbines and Power 120, no. 3 (July 1, 1998): 550–56. http://dx.doi.org/10.1115/1.2818182.
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This paper presents a physical simulator for predicting the off-design and dynamic behavior of a single shaft heavy-duty gas turbine plant, suitable for gas-steam combined cycles. The mathematical model, which is nonlinear and based on the lumped parameter approach, is described by a set of first-order differential and algebraic equations. The plant components are described adding to their steady-state characteristics the dynamic equations of mass, momentum, and energy balances. The state variables are mass flow rates, static pressures, static temperatures of the fluid, wall temperatures, and shaft rotational speed. The analysis has been applied to a 65 MW heavy-duty gas turbine plant with two off-board, silo-type combustion chambers. To model the compressor, equipped with variable inlet guide vanes, a subdivision into five partial compressors is adopted, in serial arrangement, separated by dynamic blocks. The turbine is described using a one-dimensional, row-by-row mathematical model, that takes into account both the air bleed cooling effect and the mass storage among the stages. The simulation model considers also the air bleed transformations from the compressor down to the turbine. Both combustion chambers have been modeled utilizing a sequence of several sub-volumes, to simulate primary and secondary zones in presence of three hybrid burners. A code has been created in Simulink environment. Some dynamic responses of the simulated plant, equipped with a proportional-integral speed regulator, are presented.
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Jan, Stąsiek, Jewartowski Marcin, Baranski Jacek, and Wajs Jan. "Modeling of low calorific gas burning in a deficient oxygen environment and high-temperature oxidizer." International Journal of Physics Research and Applications 6, no. 1 (March 15, 2023): 027–34. http://dx.doi.org/10.29328/journal.ijpra.1001050.
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It is planned to carry out a comprehensive experimental and theoretical study on the high temperature of low calorific gas combustion with oxygen-deficient oxidizers. The experimental research will be performed using the experimental facility with a combustion chamber. The oxygen concentration in combustion oxidizers will be varied from 21% by volume (normal) air to 2%. The test combustion chamber will be fed with propane or methane as the reference fuel, then with low calorific fuels as test gases obtained by mixing various combustible components, e.g. H2, CH4, CO, and neutral gases, e.g. N2, CO2. Gaseous fuels prepared in this way will be burned in the atmosphere of a deficient oxidizer with a temperature changing from 800 °C to 1100 °C. Oxidizers will be heated up to a certain temperature using two methods: by flue gas heat exchanger and kanthal rod electric preheater. Different burner geometry will be used. The burner will be equipped with annular swirl vanes for co-axial or under different angles, fuel, and oxidizers flow to have a high swirl number achieved by flow aerodynamics and mixing. Experimental data will be verified with numerical simulations with the use of ANSYS CFD Fluent code.
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Filinov, Evgeny, Andrey Tkachenko, Hewa Hussein Omar, and Viktor Rybakov. "Increase the Efficiency of a Gas Turbine Unit for Gas Turbine Locomotives by Means of Steam Injection into the Flow Section." MATEC Web of Conferences 220 (2018): 03010. http://dx.doi.org/10.1051/matecconf/201822003010.
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In the modern world of railways, electrification is given great importance. Currently, more than 50% of all freight traffic carried out by electric traction. However, today, about half of the railways are not electrified, so it is necessary to use thermal engines to drive the locomotive. One of the possible variant is use gas turbine unit. The power of the gas turbine unit is given to the electric generator, and the electric motors drive the locomotive. In the present paper, as a power plant of a gas turbine locomotive, considered gas turbine unit with a twin -shaft gas generator of two schemes: 1- with steam supply to the inlet of the high-pressure turbine (into the combustion chamber) and 2- with steam supply to inlet of the free turbine. By CAE system of ASTRA, Collaboration operation lines calculated for different variants of steam injection. When the steam injected into the inlet of a free turbine and a high-pressure turbine. in the case of steam supply to the input of the free turbine and the high-pressure turbine there is a significant shift in Collaboration operation lines, which can lead to a decrease in the gas-dynamical stability of the compressors, and efficiency. To maintain the position of Collaboration operation lines, was applied the correction of the throughput capacity of free turbine nozzle vanes (by 15%). In the case of steam supply to the inlet of a free turbine, to ensure gas-dynamic stability of the compressors, a change in the throughput capacity of its nozzle vanes is required.
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Husainy, Avesahemad S. N., Prasad Maruti Sawant, Sayeedahmed M. Yusuf Shaikh, Om Shashikant Virbhadre, and Mayuresh Sanjay Tone. "Review on Preservation of Post-Harvest Vegetables by Using Evaporative Cooling Method." Asian Journal of Engineering and Applied Technology 10, no. 2 (November 5, 2021): 39–44. http://dx.doi.org/10.51983/ajeat-2021.10.2.3097.
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Proper storage of vegetables, fruits and food items is necessary in order to maintain their life. The shelf life of vegetables is highly dependent on temperature and humidity in storage place. Cold room and refrigeration facilities are out of budget due to advance technologies and high electricity consumption. Affordable storage facility is highly useful in such conditions. The paper aims at developing low cost, small scale evaporative cooler that operates on a principle of evaporative cooling phenomenon. The developed model has box type of structure having water holding vessel at bottom side. The proposed model has cooling fan arranged for vertical orientation with certain height partial closed as well as medium height between cooling chamber and storage chamber. The fan has been operated at two speed variants namely low speed as well as high speed for getting results at different evaporation rates. Throttling vanes have been provided through the air entering chamber which significantly affects evaporation capacity of the evaporative box. In the given range of 270 minutes of operating time during two time slots i.e.,morning and afternoon. Humiditypercentage increase from 26 to 60 is found through the experimentation while the temperature difference was reduced down to 8 degrees of difference (40 ⁰C to 32 ⁰C) through experimentation. The performance of the developed model was found better in case of throttling with fan speed parameter that includes partial throttling at high speed and medium throttling at low speed.
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Chen, L., W. Zhang, and F. Sun. "Performance optimization for an open-cycle gas turbine power plant with a refrigeration cycle for compressor inlet air cooling. Part 1: Thermodynamic modelling." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 223, no. 5 (May 14, 2009): 505–13. http://dx.doi.org/10.1243/09576509jpe726.
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A thermodynamic model of an open cycle gas turbine power plant with a refrigeration cycle for compressor inlet air cooling with pressure drop irreversibilities is established using finite-time thermodynamics in Part 1 of this article. The flow processes of the working fluid with the pressure drops of the working fluid and the size constraints of the real power plant are modelled. There are 12 flow resistances encountered by the working fluid stream for the cycle model. Three of these, the friction through the blades, vanes of the compressor, and the turbines, are related to the isentropic efficiencies. The remaining flow resistances are always present because of the changes in the flow cross-section at the mixing chamber inlet and outlet, the compressor inlet and outlet, the combustion chamber inlet and outlet, the heat exchanger inlet and outlet, and the turbine inlet and outlet. These resistances associated with the flow through various cross-sectional areas are derived as functions of the mixing chamber inlet relative pressure drop, and they control the air flowrate and the net power output. The analytical formulae about the power output, efficiency, and other coefficients are derived with the 12 pressure drop losses. The numerical examples show that the dimensionless power output reaches its maximum at the optimal value and that the dimensionless power output and the thermal efficiency reach their maximum values at the optimal values of the compressor fore-stages pressure ratio of the inverse Brayton cycle.
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Ivanov, E. A., V. A. Kalaev, and S. A. Shumilin. "MODERNIZATION OF THE FLOW SECTION OF THE MAIN CIRCULATION PUMP GCN 22600-87." Proceedings of the higher educational institutions. ENERGY SECTOR PROBLEMS 20, no. 7-8 (September 8, 2018): 63–70. http://dx.doi.org/10.30724/1998-9903-2018-20-7-8-63-70.
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In the presented work, a new version of the design of the flow-through part of the main circulation pump for NPPs with increased energy indices is proposed. This design solution allows to increase the efficiency of the pump from 82 -83% to 88-89%. Numerical hydrodynamic calculations of the viscous fluid flow in the ANSYS CFX environment of various variants of the pump design have been performed: a spherical chamber with guide vanes, a spiral tap, a spiral tap with discharge openings in a spherical chamber (new design). As a result of the hydrodynamic calculations, the values of the hydraulic efficiency of the variants considered were obtained. As a result of the analysis of the pattern of the flow of the investigated variants, it is established that the proposed version of the pump with unloading holes has additional hydraulic losses due to circulation of the flow through them. The value of the circulation of the flow through the discharge openings is numerically obtained. The cause of the detected effect was investigated. As a result of the conducted research it is established that it is possible to further increase the efficiency of the proposed pump design by optimizing the geometry of the discharge openings.
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Raisi, Afrasiab, Sara Rostami, Afshin Ahmadi Nadooshan, and Masoud Afrand. "The examination of circular and elliptical vanes under natural convection of nanofluid in a square chamber subject to radiation effects." International Communications in Heat and Mass Transfer 117 (October 2020): 104770. http://dx.doi.org/10.1016/j.icheatmasstransfer.2020.104770.
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Natale, Nunzio, Serena Russo, Sylvie Dequand, Arnaud Lepage, and Nicola Paletta. "Aerodynamic Design of Airfoil Shape for Gust Generation in a Transonic Wind Tunnel." Aerotecnica Missili & Spazio 100, no. 4 (October 7, 2021): 345–62. http://dx.doi.org/10.1007/s42496-021-00098-y.
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AbstractThis article presents the aerodynamic design of the airfoil of the gust generator system being developed in the GUDGET project and conceived to generate high-amplitude gusts in a transonic wind tunnel. The system is made of vanes creating a flow deviation in turn by flapping around a rotational axis or by blowing air though a suitable sonic jet located close to the vane trailing edge. The airfoil shape optimization has been carried out using a design of experiment technique (DOE) and response surface optimization along with URANS CFD. The computational model has been preliminarily validated using data provided by ONERA for the baseline design at a lower Mach number ($$\hbox {M}=0.73$$ M = 0.73 ) and then compared with the one actually required by GUDGET in the test chamber ($$\hbox {M}=0.82$$ M = 0.82 ). All the cases have been optimized at a frequency of 40 Hz and then investigated at a frequency of 80Hz.
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Ventura, Austin, Natalia Gimelshein, Sergey Gimelshein, and Andrew Ketsdever. "Effect of vane thickness on radiometric force." Journal of Fluid Mechanics 735 (October 29, 2013): 684–704. http://dx.doi.org/10.1017/jfm.2013.523.
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AbstractA numerical and experimental study of radiometric forces on vanes of different thickness is presented for the flow regime where the radiometric force is near its maximum. For single- and multi-vane geometries, it is shown that radiometric force decreases by only ∼10–15 % when the vane thickness-to-height ratio increases fourfold from 0.5 to 2. For a single-vane geometry, the shear force on the lateral side of the vane is attributed to a vortex flow generated by the interaction of cold chamber walls and heated walls of the vane. In that case, it always acts to reduce the total radiometric force governed by the pressure difference between the hot and the cold sides of the vane. For a multi-vane geometry, represented by a perforated vane, the shear force becomes positive for larger thickness-to-height ratios and lower pressures, primarily due to strong vane-driven transpiration flow through the gaps.
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Markovic, Zoran, Milic Eric, Predrag Stefanovic, Rastko Jovanovic, and Ivan Lazovic. "Optimization of the flue gas flow controlling devices of the electrostatic precipitator of unit 4 in TPP "Nikola Tesla"." Thermal Science, no. 00 (2023): 24. http://dx.doi.org/10.2298/tsci220903024m.
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Homogeneity of the flue gas flow through the chamber of an electrostatic precipitator is one of the basic influencing parameter on dedusting efficiency. This paper presents results of a multiobjective optimization study of the flue gas controlling devices of electrostatic precipitator of 324 MWe lignite fired unit A4 of Thermal Power Plant "Nikola Tesla" in Serbia. The aim was to achieve better flow homogeneity in the cross-section of the precipitator compared to the original design. Additional constraints were to maintain the minimum as possible overall weight of the proposed design as well as pressure drop through the precipitator. Numerical simulations based on Computational Fluid Dynamics were used to investigate dependence of the velocity distribution in the ducts and precipitator?s chamber with respect to the geometrical parameters of tested concepts of turning blades. A series of 22 detailed full-scale numerical models of the precipitator with different concepts of turning vanes designs were developed. Assessment of the flow field uniformity for each tested design was performed based on the analysis of several homogeneity parameters calculated for selected vertical cross-sections of the precipitator. After the reconstruction according to optimized design, results of measurements confirmed significant improvements of the velocity distribution in the vertical cross-sections of the precipitator, increase of dedusting efficiency and reduction of PM emission.
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Kim, Hyoung-Ho, Md Rakibuzzaman, Kyungwuk Kim, and Sang-Ho Suh. "Flow and Fast Fourier Transform Analyses for Tip Clearance Effect in an Operating Kaplan Turbine." Energies 12, no. 2 (January 16, 2019): 264. http://dx.doi.org/10.3390/en12020264.
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The Kaplan turbine is an axial propeller-type turbine that can simultaneously control guide vanes and runner blades, thus allowing its application in a wide range of operations. Here, turbine tip clearance plays a crucial role in turbine design and operation as high tip clearance flow can lead to a change in the flow pattern, resulting in a loss of efficiency and finally the breakdown of hydro turbines. This research investigates tip clearance flow characteristics and undertakes a transient fast Fourier transform (FFT) analysis of a Kaplan turbine. In this study, the computational fluid dynamics method was used to investigate the Kaplan turbine performance with tip clearance gaps at different operating conditions. Numerical performance was verified with experimental results. In particular, a parametric study was carried out including the different geometrical parameters such as tip clearance between stationary and rotating chambers. In addition, an FFT analysis was performed by monitoring dynamic pressure fluctuation on the rotor. Here, increases in tip clearance were shown to occur with decreases in efficiency owing to unsteady flow. With this study’s focus on analyzing the flow of the tip clearance and its effect on turbine performance as well as hydraulic efficiency, it aims to improve the understanding on the flow field in a Kaplan turbine.
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Monceau, Daniel, Djar Oquab, Claude Estournès, Mathieu Boidot, Serge Selezneff, and Nicolas Ratel-Ramond. "Thermal Barrier Systems and Multi-Layered Coatings Fabricated by Spark Plasma Sintering for the Protection of Ni-Base Superalloys." Materials Science Forum 654-656 (June 2010): 1826–31. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.1826.
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Aeronautic gas turbine blades, vanes and combustion chambers are protected against high temperature oxidation and corrosion by single or multilayered coatings. These include environmental coatings, generally based on Pt-modified Ni aluminides or MCrAlY overlays (where M = Ni and/or Co), thermal barrier coating (TBC) systems including a ceramic thermally insulating layer, and abradable seals. The present work shows the ability of the Spark Plasma Sintering technique to rapidly develop new coatings compositions and microstructures. This technique allows combining powders and metallic foils on a superalloy substrate in order to obtain multilayered coatings in a single short production step. Fabrication of MCrAlY overlays with local Pt and/or Al enrichments is shown, as well as fabrication of coatings made of -PtAl2, -PtAl, α-AlNiPt2, martensitic and (Ni,Pt)Al or Pt-rich ’ phases, including their doping with reactive elements. The fabrication of a complete TBC system with a porous and adherent Yttria Stabilized Zirconia (YSZ) layer on a bond-coating is also demonstrated, as well as the fabrication of a CoNiCrAlY-based cermet coating for abradable seal application. Difficulties of fabrication are reviewed, such as Y segregation, risks of carburization, local over-heating, or difficulty to coat complex shaped parts. Solutions are given to overcome these difficulties.
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Yunus, Mohammed, and Mohammad S. Alsoufi. "Mathematical Modeling of Multiple Quality Characteristics of a Laser Microdrilling Process Used in Al7075/SiCp Metal Matrix Composite Using Genetic Programming." Modelling and Simulation in Engineering 2019 (January 2, 2019): 1–15. http://dx.doi.org/10.1155/2019/1024365.
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The conventional method for machining metal matrix composites (MMCs) is difficult on account of their excellent characteristics compared with those of their source materials. Modern laser machining technology is a suitable noncontact method for machining operations of advanced engineering materials due to its novel advantages such as higher productivity, ease of adaptation to automation, minimum heat affected zone (HAZ), green manufacturing, decreased processing costs, improved quality, reduced wastage, removal of finishing operations, and so on. Their application includes hole drilling in an aircraft engine components such as combustion chambers, nozzle guide vanes, and turbine blades made up of MMCs which meet quality standards that determine their suitability for service use. This paper presents a derived mathematical model based on evolutionary computation methods using multivariate regression fitting for the prediction of multiple characteristics (circularity, taper, spatter, and HAZ) of neodymium: yttrium aluminum garnet laser drilling of aluminum matrix/silicon carbide particulate (Al/SiCp) MMCs using genetic programming. Laser drilling input factors such as laser power, pulse frequency, gas pressure, and pulse width are utilized. From a training dataset, different genetic models for multiple quality characteristics were obtained with great accuracy during simulated evolution to provide a more accurate prediction compared to empirical correlations.
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Lacaze, Jacques, and Alain Hazotte. "Directionally Solidified Materials: Nickel-base Superalloys for Gas Turbines." Textures and Microstructures 13, no. 1 (January 1, 1990): 1–14. http://dx.doi.org/10.1155/tsm.13.1.
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From the first forged turbine blades made of iron base alloys to the present nickel base single-grain turbine blades and vanes manufactured by directional solidification, an enormous amount of research has been directed to attaining the hottest possible combustion chamber temperatures in jet engines. Temperature has been increased by about 15 K each year for the last two decades, improving the thermodynamic efficiency of the engines. The more recent developments concern the manufacturing of single-grain parts made of nickel base superalloys with large amount of the γ′ hardening phase.This paper first presents the directional solidification process used to produce single-grain parts, the formation of as-cast microstructures and the defects that can arise during solidification. In the second part the thermal treatments that are applied to the nickel base superalloys in order to enhance their mechanical properties are detailed. The effect of crystallographic orientation and of the γ/γ′ microstructure on the mechanical properties is briefly presented, as well as the. microstructural changes that can possibly arise during service.
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Iitsuka, H., M. Takao, M. M. A. Alam, S. Okuhara, H. Taniguchi, and S. Matsuura. "Effect of guide vane on the performance of a sail wing turbine for wave energy conversion." Journal of Physics: Conference Series 2217, no. 1 (April 1, 2022): 012074. http://dx.doi.org/10.1088/1742-6596/2217/1/012074.
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Abstract In an Oscillating Water Column (OWC) based wave energy plant, the sea wave motion is used to drive an air column in an air chamber and that results in a bi-directional airflow. An air turbine for bi-directional airflow is used to convert the pneumatic energy into mechanical energy. The sail wing turbine can be used as an air turbine for wave energy conversion because it has a special structure in which the shape of the sail changes in reciprocating airflow and always can rotate in the same direction. In addition, the sail wing turbine does not experience the stalling effect and can acquire energy at a wide range of rotational speed and flow rate. In our previous studies, the performance of the sail wing turbine for bi-directional airflow has been investigated by using a wind tunnel test. In the present study, in order to further improve the performance of the sail wing turbine, guide vanes were installed, and the effect of the guide vane on the performance was investigated by a wind tunnel test and a computational fluid dynamics (CFD) analysis under a steady flow condition.
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Xin, Jianchi, Xiangyang Liu, Adil Malik, Haitao Liu, Longhui Zhao, and Xiaozhi Kong. "Investigation of the Flow Field and Aerodynamic Load on Impellers under Guide Vanes with a Self-Induced Slot in Compressor Radial Inlet." Applied Sciences 12, no. 10 (May 20, 2022): 5179. http://dx.doi.org/10.3390/app12105179.
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The flow field and the efficiency of the compressor can be improved and increased by the guide vane in the radial inlet chamber. However, the guide vane generates the wake and results in the rotor–stator interaction, which threatens the safety of the impeller. This paper investigated the guide vane with a self-induced slot (SIS) in a radial inlet, and the self-induced slot was a passive flow control method. Through computational fluid dynamics (CFD) simulation, the radial inlet containing unevenly distributed guide vanes (UGVs) in the hydrogen compressor was studied to clarify the flow phenomenon in the radial inlet and the aerodynamic load on the impellers. The simulation results showed that the self-induced slot did not affect the compressor performance but improved the pure wake style to the weak wake near the shroud region. The aerodynamic load on the impeller leading edge was obtained under different radial inlets through unsteady simulation. The dominant frequency and the pulse amplitude of aerodynamic load were obtained by fast Fourier transforms (FFTs). The SIS model had lower amplitude values at the impeller passing frequency, and the reduction in amplitude was about 18% compared to the UGV model near the impeller shroud region.
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Salvadori, Simone, Massimiliano Insinna, and Francesco Martelli. "Unsteady Flows and Component Interaction in Turbomachinery." International Journal of Turbomachinery, Propulsion and Power 9, no. 2 (April 5, 2024): 15. http://dx.doi.org/10.3390/ijtpp9020015.
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Unsteady component interaction represents a crucial topic in turbomachinery design and analysis. Combustor/turbine interaction is one of the most widely studied topics both using experimental and numerical methods due to the risk of failure of high-pressure turbine blades by unexpected deviation of hot flow trajectory and local heat transfer characteristics. Compressor/combustor interaction is also of interest since it has been demonstrated that, under certain conditions, a non-uniform flow field feeds the primary zone of the combustor where the high-pressure compressor blade passing frequency can be clearly individuated. At the integral scale, the relative motion between vanes and blades in compressor and turbine stages governs the aerothermal performance of the gas turbine, especially in the presence of shocks. At the inertial scale, high turbulence levels generated in the combustion chamber govern wall heat transfer in the high-pressure turbine stage, and wakes generated by low-pressure turbine vanes interact with separation bubbles at low-Reynolds conditions by suppressing them. The necessity to correctly analyze these phenomena obliges the scientific community, the industry, and public funding bodies to cooperate and continuously build new test rigs equipped with highly accurate instrumentation to account for real machine effects. In computational fluid dynamics, researchers developed fast and reliable methods to analyze unsteady blade-row interaction in the case of uneven blade count conditions as well as component interaction by using different closures for turbulence in each domain using high-performance computing. This research effort results in countless publications that contribute to unveiling the actual behavior of turbomachinery flow. However, the great number of publications also results in fragmented information that risks being useless in a practical situation. Therefore, it is useful to collect the most relevant outcomes and derive general conclusions that may help the design of next-gen turbomachines. In fact, the necessity to meet the emission limits defined by the Paris agreement in 2015 obliges the turbomachinery community to consider revolutionary cycles in which component interaction plays a crucial role. In the present paper, the authors try to summarize almost 40 years of experimental and numerical research in the component interaction field, aiming at both providing a comprehensive overview and defining the most relevant conclusions obtained in this demanding research field.
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Tanaka, Sukehiro. "The Ecclesiastical Courts in The Early Modern Southern Netherlands: A Quantitative Analysis." Pro Memorie 21, no. 1 (January 1, 2019): 54–71. http://dx.doi.org/10.5117/pm2019.1.004.tana.
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Summary This contribution studies the cessio bonorum of painter Rembrandt van Rhijn in relation to the relevant rules and institutions of Amsterdam. I would first and foremost like to thank professor Eddy Put (KU Leuven), for repeatedly reading my drafts and providing me plenty of useful references and advice. Gerrit Vanden Bosch, Marie-Juliette Marinus, and Jos Van den Nieuwenhuizen kindly answered my many questions, and, needless to say, all the possible flaws are on my own responsibility. In conducting this research, I was supported by the Hitotsubashi University Foundation (Japan). In the Rembrandt case the procedural rules on the cessio bonorum were followed to a large extend. In regard to the beweysinge, a few weeks before the application for the cessio, it seems more convincing that it should be interpreted as a promise than as a conveyance of the house he owned. This new perspective on the beweysinge, however, does not alter the fact that it seems likely that there was a conflict between the Orphans Chamber (serving the interests of Titus) and the Insolvency Chamber (serving the interests of the creditors, and among them especially the former burgomaster Cornelis Witsen). Arguments for this are derived from: 1) the new bylaw issued by the Orphans Chamber shortly after Rembrandt’s application for the cessio, 2) the appointment of the renowned lawyer Louis Crayers as guardian of Titus (instead of Jan Verwout), and 3) the position of Titus’ preferential claim in the concursus creditorum. Crenshaw has stated that this conflict was decided by the personal influence of Cornelis Witsen. This contribution defends that Witsen only could enforce the sale of the house because of the institutional and political power structures within the city government. Witsen belonged to the powerful reigning faction of Cornelis de Graeff, whereas the majority of the officials in the Orphans Chamber belonged to the ‘political opposition’. In the end it was especially Witsen who profited from the sale (at the expense of Titus).
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ZIPF, MATTHIAS, JOCHEN MANARA, THOMAS STARK, MARIACARLA ARDUINI, HANS-PETER EBERT, and JÜRGEN HARTMANN. "Identification of wavelength regions for non-contact temperature measurement of combustion gases at high temperatures and high pressures." High Temperatures-High Pressures 49, no. 3 (2020): 241–60. http://dx.doi.org/10.32908/hthp.v49.805.
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Stationary gas turbines are still an important part of today’s power supply. With increasing temperature of the hot combustion gas inside a gas turbine, the efficiency factor of the turbine increases. For this reason, it is intended to operate turbines at the highest possible gas temperature. Therefore, in the combustion chamber and especially at the position of the first stage guide vanes the gas temperature needs to be measured reliably. To determine the gas temperature, one promising approach is the application of a non-contact measurement method using a radiation thermometer. A radiation thermometer can measure the gas temperature remotely from outside of the harsh environment. At ZAE Bayern, a high temperature and high-pressure gas cell has been developed for this purpose in order to investigate gases and gas mixtures under defined conditions at high pressures and high temperatures. This gas cell can be placed in a FTIR-spectrometer in order to characterize the infrared-optical properties of the gases. In this work the measurement setup is introduced and gas mixtures, which are relevant for gas turbine applications are analyzed thoroughly. The derived results are presented and discussed in detail. To identify suitable wavelength regions for non-contact gas temperature measurements, first tests have been performed. Based on these tests, an appropriate wavelength region could be chosen, where future gas temperature measurements can be carried out.
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Cao, Yang, Tiezhu Zhang, Hongxin Zhang, Zhen Zhang, Jian Yang, and Baoquan Liu. "Study of the Self-Locking Characteristics of the Swing Scraper of an Elliptical Rotor Scraper Pump." Machines 10, no. 5 (May 13, 2022): 370. http://dx.doi.org/10.3390/machines10050370.
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This paper proposes an Elliptical Rotor Scraper Pump (ERSP) to address traditional displacement pump defects, such as complex structures, poor self-sealing, low volume utilization, and considerable noise, etc. The ERSP utilizes a swing scraper instead of one rotor in a conventional multirotor pump or reciprocating moving vanes in a traditional vane pump and can achieve high-pressure output through pressure self-sealing. The swing scraper can divide the working chamber into high- and low-pressure rooms. Due to the small swing amplitude of the scraper, the ERSP has low operating noise. The ERSP rotor with an elliptical shape can significantly improve pump volume utilization, thus, forming a kind of fluid pump without a distribution valve, high pressure, and compact structure, and can work efficiently at high speed. This paper establishes a three-dimensional model and mathematical model for the ERSP, then develops the mathematical relationship between the scraper rotation angle and rotor rotation angle and carries out the simulation analysis based on MSC ADAMS. Then, the self-locking characteristics of the ERSP are studied through a force analysis of the swing scraper. Finally, our research group designs and produces a prototype based on existing research and verifies the superiority of the ERSP and the correctness of the non-self-locking condition through experiments. The results in this paper provide a reference for research on the self-locking characteristics of fluid rotor pumps and engineering optimization, which has great significance to the development of fluid power machinery.
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Hamid, Mohd Fadzli, Mohamad Yusof Idroas, Mazlan Mohamed, Shukriwani Sa'ad, Teoh Yew Heng, Sharzali Che Mat, Muhamad Azman Miskam, Zainal Alimuddin Zainal Alauddin, and Muhammad Khalil Abdullah. "Numerical Investigation of the Effect of Incorporated Guide Vane Length with SCC Piston for High-Viscosity Fuel Applications." Processes 8, no. 11 (October 22, 2020): 1328. http://dx.doi.org/10.3390/pr8111328.
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Compression ignition (CI) engines that run on high-viscosity fuels (HVF) like emulsified biofuels generally demonstrate poor engine performance. An engine with a consistently low performance, in the long run, will have a negative effect on its lifespan. Poor combustion in engines occurs mainly due to the production of less volatile, less flammable, denser, and heavier molecules of HVF during injection. This paper proposes a guide vane design (GVD) to be installed at the intake manifold, which is incorporated with a shallow depth re-entrance combustion chamber (SCC) piston. This minor modification will be advantageous in improving the evaporation, diffusion, and combustion processes in the engine to further enhance its performance. The CAD models of the GVD and SCC piston were designed using SolidWorks 2018 while the flow run analysis of the cold flow CI engine was conducted using ANSYS Fluent Version 15. In this study, five designs of the GVD with varying lengths of the vanes from 0.6D (L) to 3.0D (L) were numerically evaluated. The GVD design with 0.6D (L) demonstrated improved turbulence kinetic energy (TKE) as well as swirl (Rs), tumble (RT), and cross tumble (RCT) ratios in the fuel-injected zone compared to other designs. The suggested improvements in the design would enhance the in-cylinder airflow characteristics and would be able to break up the penetration length of injection to mix in the wider area of the piston-bowl.