Numerical matching of supercharger for gasoline engine based on three-line working condition method

The traditional study of matching gasoline engine and supercharger mainly focuses on the external characteristic conditions, but the reasonable matching of external characteristic conditions cannot guarantee the reasonable matching of supercharger and gasoline engine in the whole operating range. Therefore, to address the limitation of studying only the external characteristic conditions in the supercharger matching process, a thermodynamic model of a direct injection supercharged gasoline engine was established, based on which the matching between the supercharger and the gasoline engine in the whole operating range was studied by the three-line condition method. The results show that the matching performance of the supercharger in the whole engine operating range can be significantly improved by using the three-line working condition method to match the supercharger. The three-line method takes into account both fullload and part-load engine conditions, and can visually evaluate the operating efficiency of the supercharger over the entire engine operating range, as well as predict the likelihood of surging, blocking and overspeeding of the supercharger over the entire engine operating range, overcoming the limitation of studying only the external characteristic conditions and providing a numerical evaluation method for pre-selection and optimization of the supercharger.