Lin H.,Zhejiang Industry Polytechnic College |
Ding J.,BAIC Motor Powertrain Co. |
Lv L.,Zhejiang Industry Polytechnic College |
Gan W.,Zhejiang Industry Polytechnic College
Jixie Qiangdu/Journal of Mechanical Strength | Year: 2016
In order to analysis the torsional vibration of the camshaft, the dynamic experiment of valve train was conducted to calculate the dynamic torque in this paper. The torsional vibration and the critical speed can be obtained by the modal analysis, and then the relationship between the torsional vibration and working condition was analyzedto confirm the torsional vibration influence to the valve train. The results show that the torsional vibration changed with the camshaft speed, and influenced the valve timingin the out of the common working condition. The camshaft torque increased obviously by taking the torsional vibration into account. The camshaft max torque and the torsional amplitude value were 4. 5 N·m and 0.06° in the rated condition. © 2016, Journal of Mechanical Strength. All right reserved.
Wang B.P.,Beijing Institute of Technology |
Yu B.Q.,BAIC Motor Powertrain Company Ltd |
Fan Q.B.,Beijing Institute of Technology |
Fan Q.B.,Impact Lab |
And 7 more authors.
Materials and Design | Year: 2016
The anisotropic dynamic mechanical behavior of the W fiber/Zr-based bulk metallic glass composites (Wf/BMGCs) with different W fiber orientations (θf) were investigated by split Hopkinson pressure bar (SHPB) and finite element method (FEM). The composites exhibited the most excellent mechanical properties at θf of 0° while the poorest at θf of 45°. The composites failed by longitudinal splitting at θf of 0°, shearing at θf of 45°, a mixture of shearing and splitting during 0° < θf < 45° or 45° < θf < 90°, and a mixture of shearing and transverse splitting at θf of 90°. Strain rate sensitivity of the composites also varied with θf, exhibiting positive strain rate sensitivity at θf of 0°, 15°, 60°, and 75° ranging from the strain rate of 10-3 to 2.1 × 103 s-1, positive strain rate sensitivity with the strain rate ranging from 10-3 to 10-2 s-1 but negative strain rate sensitivity from 10-2 to 2.1 × 103 s-1 at θf of 30° and 90°, and even strain rate insensitivity at θf of 45°. © 2016 Elsevier Ltd.
Shi X.,Beijing Institute of Technology |
Zhang S.,Beijing Institute of Technology |
Li B.,BAIC Motor Powertrain Co.
Qiche Gongcheng/Automotive Engineering | Year: 2014
For solving the problems of soot emission deterioration and compressor surge in the acceleration process of turbocharged engine, a coordinated regulation scheme between variable geometry turbine (VGT) and variable geometry compressor (VGC) is proposed. Ricardo Wave code is used to simulate the acceleration process of a six-cylinder diesel engine under constant torque condition for investigating the effects of initial load, acceleration time and VGT openings on the soot emission of engine in acceleration process with the control rules of VGT and VGC preliminarily optimized. The results show that the coordinated regulation of VGT and VGC can not only reduce the soot emission from diesel engine but also avoid compressor surge.
Zhou Q.-S.,BAIC Motor Powertrain Co. |
Yang K.,Beijing University of Technology
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering | Year: 2014
An organic rankine cycle (ORC) system was designed to recover waste heat from a vehicle diesel engine using pure fluid R245fa and zeotropic mixture R416A as working medium. Taking power output increasing rate as measure to evaluate the diesel-ORC combined cycle system, the effects of the combined cycle system were analyzed under various engine conditions. Results show that with engine speed and torque increasing, net power outputs of the combined cycle system using both two different working mediums increase; the max. net power output increments are 30.39 kW for R416A and 28.03 kW for R245fa. Combined cycle system power output increasing rates using two working fluids, R416A and R245fa reach up to 9.70% and 9.00% respectively. The effect is better when using zeotropic mixture R416A.
Zhan Z.-S.,Beijing Institute of Technology |
Shi X.,Beijing Institute of Technology |
Peng W.,BAIC Motor Powertrain Co.
Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics | Year: 2016
The inlet pulsation in twin-entry turbine on automotive turbocharger was not synchronized. The performance of the turbine designed on steady changed when working under actual condition. To achieve higher efficiency, the numerical simulation was used to study the flow field of turbine when the pulse frequency was 40 Hz. The results showed that the more unbalance of the pressure between the two channels was, the worse the efficiency and flow capacity of the turbine were. The variation of the incidence angle had great influence on turbine rotor flow field. The incidence angle at the rotor inlet varied along leading edge, its value was also related to the inlet pressure of the turbine stage. Besides, the pulse wave mainly affected the separation flow on suction surface. © 2016, Science Press. All right reserved.
Li W.,Dalian University of Technology |
Li W.,Dalian Jiaotong University |
Xue D.,Dalian University of Technology |
Song X.,Dalian University of Technology |
And 2 more authors.
Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering | Year: 2014
The heat release of a chemical reaction is a major source of combustion noise in internal-combustion engines. The simulation grid cells in the combustion chamber whose heat release changes as the crank angle changes serve as noise sources. These sources produce acoustic waves. By means of combining the acoustic theory and the KIVA program, the regions around the noise sources are divided into the cells inside the acoustic wave and the cells outside the acoustic wave respectively according to the range of acoustic wave propagation. Therefore the pressure of the cells are calculated on the basis of the cells lying in the different regions. The process of pressure oscillations in specific positions can be shown in the results. The characteristics of the main acoustic sources which caused the pressure oscillations can be analysed. On comparing the simulations and the experiments, the hysteresis effect of acoustic wave propagation can be taken into account when studying the combustion process in internal-combustion engines. © IMechE 2014.