Investigating a New Method-Based Internal Joint Operation Law for Optimizing the Performance of a Turbocharger Compressor

Abstract

A well-matched relationship between the compressor and turbine plays an important role in improving turbocharger and engine performance. However, in the matching of turbocharger and engine, the internal operation relationship between compressor and turbine is not considered comprehensively. In order to fill this gap, this paper proposed the internal joint operation law (IJOL) method based on the internal operating characteristics of the compressor and turbine using a combination of experimental and simulation methods. On this basis, the optimization method of the compressor was proposed. Firstly, according to the basic conditions of turbocharger, the compressor power consumption and the turbine effective power at a fixed speed were solved. Secondly, the power consumption curve of the compressor and the effective power curve of the turbine were coupled to obtain the power balance point of the turbocharger. Then, the internal joint operating point was solved and coupled to obtain the IJOL method. Finally, the IJOL method was used to optimize the blade number and the blade tip profile of the compressor. The simulation results showed that for the blade number, the 8-blade compressor had the best overall performance. For the blade tip profile, compared with the original compressor, the surge performance of the impeller inlet diameter reduced by 3.12% was better than that of the original compressor. In addition, in order to compare this to engine performance with different compressor structures, a 1D engine model was constructed using GT-Power. The simulation results showed that the maximum torque of the engine corresponding to the impeller designed by the IJOL method was 4.2% higher than that of the original engine, and the minimum brake specific fuel consumption was 3.1% lower. Therefore, compared with the traditional method, the IJOL method was reasonable and practical.