Papers by Keyword: Compressor

Abstract: This article presents a finite element simulation method for airflow resistance of material to predict the influence of absorption material applied to compressor box. To obtain the real airflow resistance, a measurement system based on the standard ASTM C522-03 was systematically built up and carefully verified. Furthermore, commercial finite element software, COMSOL Multiphysics, was adopted to create the model and execute the simulation with and without absorption material. Results showed that airflow resistance increases with the thickness and the density of the material. This system is quite stable and suited to any material. With the aid of COMSOL Multiphysics simulations, the performance of noise with and without absorption material can be analyzed and compared with experimental results. There was good agreement between experimental and simulation results. Based on absorption material of 15,278 Pa.s/m³ airflow resistance, the noise level outside the compressor box obtained from experiment was around 10 dBA higher than that obtained from simulation.

Abstract: Variable swash plate compressors recently have been used to improve fuel efficiency and SCM 435 or UNS C67300 were used as the material to manufacture them.As a result of structure analysis through static analysis that used ANSYS, SCM 435 currently being used was found structurally safe as it has that maximum stress is within the allowable range of their material property. Therefore, UNS C67300 was found to generate better fuel efficiency than the existing SCM 435 through structure analysis for automotive variable swash plate air conditioning compressor.

Abstract: Tip clearance of compressor rotor blade is introduced for avoiding friction collision between the moving blade and the casing. Because of the existence of the pressure difference between pressure surfaces and the suction surfaces of the blade, the blending of the leakage flow with the mainstream causes losses, which affects internal flow field and overall performance of the compressor. In this article, numerical analysis software is used to study the multi-condition performance of a six and a half axial flow compressor, for analyzing the impact of leakage flow patterns on compressor.

Abstract: The compressor contains the oversized cylindrical cavity with two interference output units each in the figure of a circular waveguide H-tee. The H-tees are coupled by a waveguide section and the energy is extracted synchronously through two output ports. The synchronism is provided through using a single microwave switch mutual for both H-tees. Simulation and experimental study of the X-band microwave compressor were carried out. The simulation made it possible to optimize the configuration of the oversized storage cavity and the output element. The amplification factor was 14 dB when the energy was extracted though one output unit at the output pulsewidth of 6...7 ns. Amplification factor and the output power were increased by 2dB and the pulsewidth was decreased down to 3...3.5 ns when the energy was extracted synchronously through two output units.

Abstract: An increase of a combustion chamber volume of internal combustion engines (ICE) is connected with the solution of a problem of burning in cylinders of bigger amount of fuel. Thus, providing the complete burning, a full scavenging of cylinders and maintenance in permissible limits of temperature of exhaust gases requires increasing air supply. The most effective method of increase in amount of air is an increase of its density by means of preliminary compression in the compressor with the subsequent cooling. It should be noted that high complexity and a large labor content of the natural experiments do not allow receiving the reliable values of gas-dynamic characteristics of air flow in a compressor of a turbocharger. Therefore, by means of a computer code of computational fluid dynamics ANSYS-CFX, numerical studies of a flow in gas channel of a compressor of the KAMAZ engine are carried out. The integrated values of pressure, temperature in inlet and outlet of a compressor, received during numerical simulations, allow defining the air compression ratio, and also calculating compressor efficiency. Verification of the results of the numerical studies and of the natural experiment gives an agreement of the values with accuracy 1-5%. Hereafter, analysis of the calculation results, and optimization of the gas channel geometry of the compressor can allow improving gas-dynamic parameters of the compressor. This can lead to raise in techno-economic characteristics of the ICE.

Abstract: Aircraft engines are exposed to degradation due to several factors such as environmental air pollution, fuel content and ageing or degradation of engine’s components, which are experienced within specified time. While the turbofan in operation, its components deteriorate and consequently affect its performance. This study is aimed to computationally investigate the effect of components degradation on engine performance. A high bypass turbofan engine operated at cruise is selected for this evaluation and the simulation was performed using the Gas Turbine Simulation Program (GSP). The affected components considered are turbines and compressors with deterioration rate ranging from 0% to 5%. The effect of selected deterioration rate on engine thrust and thrust specific fuel consumption (TSFC) is studied. Results obtained show an agreement with literature where reduction in engine thrust and TSFC are observed. Turbine’s fouling has been found to be more severe than erosion in terms of power and efficiency losses. However, in terms of the overall performance, the erosion effect is more severe than fouling.

Abstract: The new energy electric bus has already been used for many years; however, it is also not strange that there are problems in the actual operation process. Base on the running status of new energy vehicles during the early stage, this article provides some opinions on problems of using electrically driven compressor, which is mainly stated oil carryover and vibration noise of several kinds of electrically driven compressor and enumerated the partial performance of the compressors. After all, the behavior of compressor will not only directly affect the braking safety performance, but also had a greater influence on the Sequential maintenance costs.

Abstract: Due to the fact that the low speed pump similarity theory is only applicable to incompressible fluid, this theory cannot be used for extrapolation of compressor performance curve. Considering the compressibility of working medium; therefore, this paper has modified the similarity theory and put forward a new index relationship equation. The two low speed performance lines which are already known were used to get the similar working points and extrapolate the performance lines through the optimization method. Compared with the existing performance lines, the results show that the method is simple, convenient and qualified with practicability and accuracy. This method plays an important role on studying startup process of a gas turbine and improving the accuracy of the simulation of startup process.

Abstract: Centrifugal compressors of turbochargers operate in a wide range of rotational speeds, which depends on the load of the supercharged engine. Current designs of turbocharger compressors exhibit high efficiencies accompanied by high flow capacities [1]. Consequences of aerodynamic optimization are high mean stress values in the blades due to centrifugal loading as well as dynamic stresses due to blade vibrations. Blade vibrations in a turbocharger compressor are assumed to be predominantly excited by unsteady aerodynamic forces [2]. These forces are caused by a variety of sources influencing the flow. Examples include the geometry of the flow channel, elbows, the diffuser vanes or struts. Therefore, an understanding of FSI is essential for further design optimizations.

Abstract: In this paper, the 3D flow analysis model of gasoline engine turbocharger compressor was built by using the software NUMECA. The flow fields of the vaneless diffuser and volute, such as airflow velocity field, temperature field, pressure field and the entropy field were simulated. The internal flow performance of the vaneless diffuser and volute were analyzed. The simulation results show that the field changes accord with the compressor characteristics, thus the vaneless diffuser and volute of the compressor design is reasonable. The approach of numerical simulation and flow field analysis by using CFD method can accurately predict the compressor performance. The research methods and conclusions provide theoretical and practical reference for the optimization design of the compressor.