Name : [in Japanese]
Date : March 16, 2022 - March 17, 2022
In recent years, global-scale environmental problems such as resource depletion and global warming have occurred and solving these problems has become an important issue. In the automobile industry, electric vehicles and hybrid cars are attracting attention due to emission regulations, but the share of gasoline engine vehicles is still high, so it is necessary to improve the efficiency and energy saving of gasoline engines. Therefore, the downsizing concept, in which a turbocharger is mounted on the automobile engine to reduce the displacement while maintaining the output performance, has become the mainstream. However, as a problem existing in the centrifugal compressor for turbocharger, there are unstable phenomenon such as surge and rotating stall. These phenomena should be avoided because they cause damage to the device itself and noise. Since it is necessary to operate a turbocharger for automobiles at a low-speed torque, it is an important issue to suppress such an unstable phenomenon and expand the operable range in a centrifugal compressor for a turbocharger. In this study, it was confirmed by experiments whether the effect of suppressing the turning stall can be obtained by providing a gap called a slit in the diffuser vane. In addition, focusing on the wing loading distribution of the impeller, the effect of suppressing backflow and reducing surge by changing the wing loading bias on the impeller tip side was verified by CFD analysis and experiments.
