An Investigation of Flow Characteristics of Radial Gas Turbine for Turbocharger under Unsteady Flow

과급기용 Radial Turbine의 비정상 유동특성에 관한 연구

Turbocharging is one of the best methods to improve the performance of diesel engines, because of its merits,-power ratio, fuel consumption and exhaust emissions. Most of them in small and medium diesel engines have adopted the pulse turbocharging method with twin entry vaneless radial turbines to maximize the energy utility of exhaust gas. This method requires the high performance of turbine under unsteady flow, and also the matching between turbine and diesel engine is most important. However, it is difficult to match properly between them. Because the steady flow data are usually used for it. Accordingly, it is necessary to catch the characteristics of turbine performance correctly over the wide range of the operation conditions under unsteady flow. In this paper, the characteristics of turbine performance under unsteady flow are represented at varying conditions, such as inlet pressure amplitude, turbine speed and frequence.