The Improvement Design Of The 495QME Gasoline Engine Intake System Basing On CFD

The intake process of the internal-combustion engine has a significant impact on performance; it is an important component of the internal-flow system. The more fresh air entering the cylinder per cycle, the more heat it can emit, thus increase the engine power and torsion, this is prerequisite and key of guaranteeing to the engine power performance. In addition, the scavenging process also play an important role in solving those problems such as the contradiction of high, low-speed performance, the mixed gas composition of gasoline engine, uniform distribution and gas flow inside cylinder etc. So, that has also affected the economy, emissions, noise and ride comfort and so on of the vehicles. This article has conducted the research and the improvement to the 495QME gasoline engine intake system.On the foundation of sufficiency study with the internal and external literatures correlate with the problem, this article has summarized the numerical simulation development and present situation of the four stroke engine intake process systematically, has studied the mathematics and physical model which involves , has made the improvement design to the 495QME gasoline engine intake system, and carried on a detailed simulation and contrast analysis to the intake system before and after improvement of 495QME gasoline engine by using the fluid analysis software AVL FIRE, considering the influence of the intake port structure, combustion chamber pattern and cam shape line to the intake process comprehensively, made the simulation process close to the actual intake process. Has demonstrated the spatial distribution and change along with the crank angle of flow field during the intake process in detail, emphatically analyzed the flow field evolution rule, the flowing characteristic and the macroscopic parameter inside the "intake port-valve-cylinder" intake system.The experiment of 495QME gasoline engine intake system which has been improved was done, in order to measure the inlet flow under different valve lift. And carried on the comparison with the simulation value, the computed and the experimental result indicated that, both tally basically, this proved the correctness of three dimensional numerical simulation. Obviously, the computer simulation has the advantages such as the facilitate adjustment of parameters, the quick running rate, thelow-cost, it can discover the key control variables in the multitudinous influence factor, and optimize the Program of experiment and design, reduce cycles and costs of product research and design, is an effective means of research and design.