Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 07, 2019 - November 08, 2019
With the global awareness of the environmental protection, regulations related to exhaust emission from an automobile is strengthened and enhanced. Because the turbocharger can make up for the displacement volume being decreased by downsizing engine, it is considered to be effective device for the improvement of the fuel consumption and the reduction of carbon dioxide. The turbocharger is used in the wide range from a low rotational speed to a high rotational speed. However, the appearance of shock wave in the compressor causes some problems in high rotational speed. A purpose of this study is to clarify the effects of the generation of shock wave on the flow field in the compressor. The pressure near the tip of blade of compressor is measured at different rotational speeds of impellers and these pressure histories are compared with each other. In this study, the performance test facility of the turbocharger with a combustor is used. The hot air compressed by a compressor is heated by the combustor and is used as the driving source of the turbine. The total inflow to the turbine is adjusted by a control valve, and the rotational speed of the impeller is set to 120000 rpm to 140000 rpm. As a result, when the rotational speed of the impeller increases, the mean pressure near the tip of blade decreases, and the scale of the pressure change increased. When a circumferential speed of the impeller reaches the transonic speed, the pattern of pressure change is distorted in the process of pressure increase.
