SI엔진에서 스로틀 개폐에 따른 비정상상태 유량 변화에 관한 연구

In an SI engine, the characteristics of the air flow at unstedy state is important not only for the design of the intake system geometry but also for the accurate measurement of the induction air mass. In this study, a measurement of air flow rate was conducted by using the hot wire flow meter at the upstream of the intake port and the throttle. At the upstream of the throttle, the overshoot phenomena of the air flow rate by fast throttle opening were analyzed by relating choked flow and throttle area. At the upstream of the intake port, the cylinder variation of the air flow rate and the difference between fast throttle opening and closing were showed during the unsteady state by the throttle step change. The results of this study can be used for the design of the throttle valve geometry and cylinder by cylinder control.