4행정 가솔린 기관의 배기계 맥동압력 전달특성에 대한 주파수 해석

Pulsating pressure of exhaust system is generated by pulsating gas flow due to working of exhaust valve. The pulsating gas flow is closely concerned to engine power loss according to back pressure and exhaust noise. However, because of nonlinear effect due to large amplitude of pulsating pressure. it is difficult to exactly calculate pulsating pressure propagation in exhaust system of typical engine, Moreover, in case of estimating exhaust system performance, conventional prediction method which is based on linear theory, gives many restrictions and overestimate. As the first step for solving this problem, this paper contains experimental model to measure pulsating pressure propagation and shows power spectrum density, frequency response function, coherence in frequency domain for characterize pulsating pressure propagation in exhaust system of typical engine.