The Optimization Of The Combustion In 2135

The flow and combustion processes in the cylinder of internal-combustion engine is very complex, so it is important to get the real information 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 beginning of design, we choose the optimist parameters to reduce the investigation and manufacture cycle of diesel engine greatly and cut exploitation cost.In this thesis, the inlet-air,spray and combustion processes in Diesel, which has four different combustion chamber, are calculated for a purpose that get the every in-cylinder states at any time; And then the next step is to analyze the calculating results and to get the effect of the combustion chamber form on the combustion; In conclusion, an optimization chamber form is gotten. In the beginning, the correlative data are collected as more as possible, and four chamber structures are chosen: offsetωchamber,long-neckωchamber,doubleωchamber and flat-roofed chamber. The second step is to establish the modeling, plot the grid, defined the moving grid, enacted the parameters, compute and post-process with STAR-CD suites. After all these process, the last step is to analyze the simulation results of these chambers and then chose the best chamber form of them.With the digital calculation and the post-processing, the best chamber of four chambers is gained: off-setωchamber, which has a best combustion effect and an optimization work-capability, has a best air-fuel mixture production velocity, has a maximum equal-fuel heat release and combustion velocity. The second one is that theωchamber has a best atomization quality in two species chambers (open and half-open). The normal pressure inlet and supercharging inlet are calculated. The result is that the supercharging accelerates the combustion process, increases the contact area between fuel and air, improves the atomization quality and effect which is very notable to doubleωchamber. Changing the nozzle location in the offsetωchamber, the combustion effect and work capability are improved.