The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Andrii Rogovyi - One of the best experts on this subject based on the ideXlab platform.
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The Wall Erosion in a Vortex Chamber Supercharger Due to Pumping Abrasive Mediums
Lecture Notes in Mechanical Engineering, 2019Co-Authors: Andrii Rogovyi, Sergey Khovanskyy, Irina Grechka, Jan PitelAbstract:The rapid wall erosion of the settings of pump elements occurs during pumping of two-phase mediums, in the hydraulic and pneumatic transport systems. In these circumstances, it is reasonable to use the jet technology in general and the vortex chamber Superchargers in particular. The vortex chamber Superchargers have the best, compared with other jet Superchargers, energy efficiency indicators during pumping of bulk materials. The purpose of the article is to study the wall erosion of the vortex chamber. The mathematical modeling of the flow is carried out by solving the averaged Reynolds equations using a SST turbulence model corrected. Simultaneously with the hydrodynamic calculations the trajectories of abrasive material solid particles were calculated. Finney’s model was used to model the wall erosion. It is found that for all values of the flow rates and, accordingly, the concentration of solid particles, a uniform wear of the vortex chamber is observed. To ensure the durability of Superchargers it is necessary to increase the thickness of the chamber’s walls. In the process of wear, the ratio of diameters of the inflow channels to the diameter of the vortex chamber will increase. It affects the energy characteristics of the supercharger: the efficiency, the amount of medium at the outflow of the device, the vacuum value near the axis. By setting minimum acceptable parameters it is possible to predict the wear of the chamber and calculate the resource of the supercharger without the use of expensive experimental investigations.
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Energy performances of the vortex chamber supercharger
Energy, 2018Co-Authors: Andrii RogovyiAbstract:Abstract The problem of reliability and productive life of Superchargers is very acute in systems of pneumatic and hydraulic transport. One of the ways to solve this problem is to use the jetting technology. The vortex chamber Superchargers studied in this work are new devices of jetting technology and have better performance indicators in comparison with classical jet devices. It has been experimentally proved that the ejection ratio for the solid particle of the developed Superchargers is twice that of the jet ejectors. This is explained by the use of a centrifugal force in a vortex chamber, which contributes to the accumulation of more kinetic energy of the pumped solid particle. The energy performance of vortex chamber Superchargers was obtained experimentally and by modeling. Experimental studies were carried out on a specially designed experimental setup with a supercharger model. Studies were carried out in water, air and when pumping coal dust. Numerical calculations were carried out while solving the RANS equations, using the SST model of turbulence and streamline curvature correction.
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Application of the similarity theory for vortex chamber Superchargers
IOP Conference Series: Materials Science and Engineering, 2017Co-Authors: Andrii Rogovyi, Sergey KhovanskyyAbstract:On the basis of similarity in vortex chamber Superchargers criteria of similarity are defined and their check by numerical researches is made. Vortex chamber Superchargers have the big power efficiency of pumping, in comparison with classical jet pumps, at the expense of association of advantages of centrifugal and jet pumps on the basis of the vortex chamber. The concept of vortex chamber Superchargers is based on a new principle of energy transfer in jet Superchargers at the expense of hydrodynamic effects of rotating flows use. In consequence of pressure decrease near to an axis of the vortex chamber occurs intaking particles of a pumped over flow. Having got to the vortex chamber, particles get tangential velocity interact with a rotating flow at the expense of a momentum exchange. The received criteria take into account of three major factors of similarity: the geometrical sizes, pressure of an active stream on an input in the device, working medium density. Validity of the received criteria is confirmed by a finding of pressure-flow rate characteristics of similar operating modes of a supercharger and their further combination on one characteristic.
Philippe Obernesser - One of the best experts on this subject based on the ideXlab platform.
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Air System Proposal and Testing for a Downsized Two-Stroke Diesel Engine
Proceedings of the FISITA 2012 World Automotive Congress, 2013Co-Authors: Pavel Brynych, Luděk Pohořelský, Jean-charles Ricaud, Pierre-yves Vallaude, Pascal Tribotté, Jan Macek, Philippe ObernesserAbstract:This paper introduces a research work on the air loop system for a downsized two-stroke two cylinder diesel engine conducted in framework of the European project dealing with the powertrain for Future Light-duty vehicles—POWERFUL. The main objective of the work presented in this paper was to test engine air loop system devices selected based on 1D-simulations and to verify their characteristics used for 1D-simulations. With respect to the power target of 45 kW and scavenging demands of the two cylinder two-stroke engine with a displacement of 0.73 l, a two stage boosting architecture was required. Further, to allow engine scavenging at any operation, supercharger had to be integrated in the air loop. Various air loop system layouts and concepts were assessed based on the 1-D steady state simulation at full and part load with respect to the fuel consumption. Among the investigated boosting devices were the positive displacement and centrifugal Superchargers driven from the crankshaft and placed upstream or downstream of the turbocharger with either the waste gate or variable turbine. Due to the high boost pressure ratios above five and low mass flows, all boosting devices got at their limits or out of their working range even in the two stage configuration. The simulation part of the work has been presented on SAE World Congress 2012 held in Detroit (USA) (SAE paper no: 2012-01-0831), but the main results will be also presented in this paper to highlight the main issues met during the whole research work. The best compromise regarding the feasibility, power target and fuel consumption was the configuration with the positive displacement supercharger placed downstream of the waste gate turbocharger. However, the biggest drawback of this solution was the necessity of sufficient air cooling between the stages due to the limitation of the maximum temperature at the outlet of the supercharger at 150 °C. On the other hand, the boosting system with the supercharger upstream of the turbocharger required small compressor wheel to avoid surge and was ruled out due to the turbocharger procurement feasibility. After the selection of suitable boosting devices, its testing followed. There had been two types of supercharger tested, Roots type and mechanically driven centrifugal compressor with Continuously Variable Transmission (CVT). Concerning turbocharger, there has been tested device with waste-gate turbine at open loop test rig at different temperatures at turbine inlet. The measured data has been then compared with “paper characteristics” delivered by producers of tested boosting devices for simulation use. The greatest differences in measured and “paper data” had been detected at T/C turbine efficiency.
Brandon Biller - One of the best experts on this subject based on the ideXlab platform.
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A design methodology for combined turbo and supercharger applications
Proceedings, 2015Co-Authors: Roberto Rastelli, John Shutty, Brandon BillerAbstract:The significant growth forecasted in gasoline boosted engines and the more challenging regulatory requirements for emissions and fuel economy are leading to an aggressive engine downsizing trend. Two technology leaders have partnered in order to offer an optimized design in dual boosting systems which combine Superchargers and turbochargers. The result is an air delivery boosting system that can accommodate high BMEP at all engine speeds without compromising transient response. Combining the skills of both companies, the advanced engineering groups joined efforts to perform an extensive simulation study over the course of a year aimed at defining a superior system design methodology. This study explored and analyzed the benefits of each boosting device. Two main configurations were considered based on the relative sequence of each device in the air path, namely: supercharger (SC) + turbocharger (TC) and TC + SC.
Ricardo Martinez-botas - One of the best experts on this subject based on the ideXlab platform.
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Characterization of a supercharger as boosting & turbo-expansion device in sequential multi-stage systems
Energy Conversion and Management, 2017Co-Authors: Alessandro Romagnoli, Giovanni Vorraro, Srithar Rajoo, Colin Copeland, Ricardo Martinez-botasAbstract:Abstract This paper proposes a detailed performance analysis and experimental characterization of a high-pressure supercharger in a multi-stage boosting system (turbo-super arrangement). Infact, besides the technical challenges associated with achieving adequate tuning, interoperability and driveability of multi-stage boosting systems, another challenge lies in their performance prediction during engine design. Indeed, performance maps of single boosting systems are usually provided by manufacturers and used as look-up tables in 1-D engine models. Tests are usually conducted in a standalone mode, with no information provided on the behaviour and performance of the combination of more than one boosting device. The supercharger was tested with varying inlet pressures and temperatures matching on-engine operating conditions and the results were then used to assess the effectiveness of 1-D engine models performance prediction when dealing with multi-stage boosting systems. An assessment on heat transfer in Superchargers was also carried out together with the analysis on the nature of non-dimensional performance maps when dealing with a pressurized inlet. Finally, the analysis also looked into the opportunity to use the Superchargers as expanders (‘expansion mode’) in order to cool the air charge entering the engine. The results showed that there is discrepancy between the efficiency values computed by 1-D engine models and those obtained experimentally under pressurized/heated inlet air conditions; the correction of the efficiency maps for heat transfer plays a significant role in the final measured efficiency and the correction of the maps for varying inlet temperatures must be carried out in order to avoid incurring in apparent efficiencies greater than unity. The experiments on the supercharger in ‘expansion mode’ showed that low isentropic efficiencies can be achieved; despite this, 1-D engine simulations showed that it is possible to achieve savings of a few percentage points in Brake Specific Fuel Consumption when the supercharger is used to recover some throttling energy by expanding the close-to-ambient pressure to the required intake pressure.
Park Kyoun Oh - One of the best experts on this subject based on the ideXlab platform.
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A study on the composite screw rotors for Superchargers
Composite Structures, 1995Co-Authors: Young Goo Kim, Kwang Seop Jeong, Dai Gil Lee, Park Kyoun OhAbstract:In this work, the screw rotors for Superchargers were manufactured with chopped carbon fiber epoxy composite materials by resin transfer molding process. The manufactured composite screw rotors were tested in different combinations such as the male composite and female composite rotors, the male composite and female aluminium rotors, and the male aluminium and female composite rotors. The temperature and pressure increases of the air at the outlet and the required torque of the supercharger were measured with respect to the angular velocities. © 1995.