排気系システム内のバルブ開放時に発生する空力騒音

抄録

This research is refer to reduce aerodynamic noises at the exhaust systems of the truck equipped with a diesel engine. This paper, focuses on a butterfly valve in the exhaust systems. This research clarifies the property of aerodynamic noise generated by the butterfly valve during an opening operation. The noise was measured by changing the opening time. The experimental results show frequency characteristics of the noise is strongly related to the angle of the butterfly valve. Also, to slow down the opening operation of the butterfly valve, effect on the suppression of aerodynamic noise.