Simulation On Performance Optimization And Matching Of Variable Geometry Turbocharger For Highly-intensified Diesel Engine

Along with the increasingly lack of energy sources and the increasingly strict requirement of the customer, the famous diesel engine manufacturers persist in improving their products in terms of power-to-weight and power-to-volume for designing the next vehicle. But at present, the domestic design and manufacture of highly-intensified diesel engine has more difference with the same as oversea ones in the terms of power, specific fuel consumption and reliability. In this paper, the simulation study of performance of highly-intensified engine is conducted, and the research on the match principles between highly-intensified engine and variable geometry turbocharger is investigated.In this dissertation, firstly, mathematics description of physical subsystem in diesel engine is developed. Furthermore, a mathematics model for highly-intensified diesel engine is established. At the same time one-dimension unsteady flow equations presented for gas flow characters in intake and exhaust systems have been used.Referred to the related literatures and based on over-all structural analysis of domestic highly-intensified engines, the thermodynamics simulation model of highly-intensified engine by GT-POWER is established and necessary parameters are estimated. The results show that the calculated values agree well with tested values. So it is proved that the simulation model is credible, and on the basis of model, the simulation of rated condition is conducted, and main performance is predicted. For further improving the performance, it is necessary to optimize operating and configuration parameters. After confirming constraint and parameters, an optimization model aim to obtain maximum power in rated condition is set up. The computation results indicate that the effect on optimization is satisfying.According to the performance demand, the scheme argumentation of supercharging system has been carried out. Single-stage variable geometry turbocharger is decided to adopt in the highly-intensified engine. With the simulation computation model of variable geometry turbocharger, the matching principles between variable geometry turbocharger and highly-intensified engine have been investigated and analyzed in this paper. By means of simulation, the influence of the rack position on performances of the engine is analyzed and summarized. The combination operating curve variable geometry turbocharger and highly-intensified...