Simulation And Optimized Design Research For Engine On Hybrid Electric Vehicle

Global economic crisis have a serious impact on the automotive industry. Growing problem of energy shortage and environmental polution has been making the automotive industry face new challenges. Hybrid electric vehicles has become an inevitable choice for the development of the automotive industry. The Otto cycle gasoline engine hadn't met the demand for hybrid electric vehcles. Now the Atkinson cycle engine has become a new direction of the engine using in the HEVs for its high efficiency.The thesis based on software GT-POWER is applied for establishing the calculation model of gasoline engine using in the HEVs. Through the analog computation result campare to the test result, the model has been confirmed valid and accurate. On the basis of the model, guiding by principle of the Atkinson cycle, the compression ratio and valve timing has been optimized, and a best design of compression ratio and valve timing has been proposed. Calculating the effects of the intake and exhaust system parameters on the valumetric efficiency. The intake system parameters include the length of main pipe, volume of steady-pressure box, length and diameter of manifold. The exhaust system parameters include the length and diameter of main pipe , length and diameter of manifold. Optimal design these parameters and put forward a suggestion for the improvement.The end, the optimal design of simulation work has been applied to the old engine, and made some improveement. A engine test has been carried out to the improved engine. The content of engine test includes speed characteristics test and load characteristics test. After analyzing the test results, a camparsion between the calculation results and test results has been done. The results showed that the optimal design has achieved the desired objective.