Development of a Small Mixed-Flow Turbine for Automotive Turbochargers

Abstract

In recent years, turbocharging technologies for passenger cars have progressed significantly. However, “Turbo Lag” is still one of the most important problems in turbocharging technologies. In order to improve response to acceleration, it is effective to reduce the polar moment of inertia of rotating parts. The turbine rotor designed with small diameter, light weight and high specific-speed contributes toward reducing inertia moment of the rotating parts. The further request for the smaller moment of inertia for passenger car applications made it difficult to satisfy the request with a conventional radial turbine rotor. This is why we developed a mixed-flow turbine rotor. This paper explains the computer analysis we carried out and experimental test data of the mixed-flow turbine for passenger car applications.