The Design And Simulate Of Two-stage Turbocharger Facing To V12 Engine

With the development of vehicle engine technology, the requirements of diesel engine speed and power are continuously improved. Meanwhile, the two-stage turbocharger is concerned because of its ability to provide the engine with a large total pressure ratio and a wide range of air flow. But it is worth noting that if the two-stage turbocharger cannot match the engine well, there will be many problems, such as low-speed transient performance, high speed exhaust back pressure, fuel economy and other issues. Therefore, the matching of the two stage turbocharger and the engine is an important subject. This paper include the procedure of matching a suitable two-stage turbocharger with a specific V12 diesel engine, using the simulation and experiments.First, the specific parameters of the V12 engine were calculated. Main numerical calculations include the pressure ratio and reduced flow rate of the high and low-stage compressor, as well as the expansion ratio and reduced flow rate of the high and low-stage turbine. On this basis, both compressors and turbines for the engine were selected.Secondly, simulation between the two-stage turbocharging system and engine were carried out by using Ricardo WAVE software. Based on the single-cylinder engine model, the simulation model of the V12 engine was set up to do the simulation under the condition of maximum torque and maximum speed. Then the results between simulations and design parameters were compared. Under the condition of 2500r/min, the optimistic valve opening was determined through the simulation results of different openings.Finally, the high-pressure turbine volute was designed. The design task was based on the turbine specific parameters to determine A/R of the critical section. Then, the experiment of the designed turbine was undertaken to get the mass flow characteristic and efficiency characteristics, in order to verify whether the design of the turbine volute can meet the requirements.