The Optimization Of The Chamber In 2135

The flow process in the cylinder of internal-combustion engine is very complex, so it is important to get the real information of flow in the cylinder which is related to organizing high efficient combustion and clean emission. Along with the development of science and technology, the 3-D numerical simulation of this flow process exerts its unprecedented function in forecasting the performance of diesel engine and instructing the design of combustion system. The simulation can replace part of engine experimentation, in the initial stage of design, we choose the optimist parameters to reduce the investigation and manufacture cycle of diesel engine greatly and cut exploitation cost. However, the 3-D digital simulation can't simulate the actual process of diesel engine completely, it can only provide some reference and we must determine the design of the diesel engine properties by experiment. Since the PIV appeared, it provides much techno-sustain when we study the flow process in the cylinder. The PIV technology developed from the end of 70s. The PIV(Particle Image Velocimetry )can measure two dimension and three dimension distribution of velocity vector in the same area at one time, because the technology belongs to non-contact and instantaneous method, the precision of this measurement is very high.In this thesis, we combine the PIV technology and the computer numerical simulation to optimize the chamber of 2135 diesel engine, and provide advices in improving its combustion and emission. In the first step, we collected the correlative data as more as possible, chose several chamber structures preferable and established the modeling, plot the grid, defined the moving grid, enacted the parameters, computed, deal with the result with STAR-CD suites. After all these process, we gained the flow vector graph of the inlet and compress stoke at any time or position. At the moment, we analyze the simulation results of these chambers then chose the better ones of them for next work. Secondly, we altered the diesel engine chamber structure according to the simulation and used the PIV technology to test the chambers which had been altered. At the specific crack corner, we got the flow vector graph which is vertical with the cylinder axes. Compared with the results of simulation, we found the most optimized chamber structure.After the modeling and practice, we choose this best flow chamber, whose structure is used to crash, converge and recombine the whirl and improve the rotate speed adaptability, resolve the problem of the weakness in low-speed whirls and strong in high-speed whirls,...