In order to improve the sound quality of vehicle exhaust noise, especially the problem of exhaust order noise in low-frequency band, a kind of adjustable lumped inertance resonator (ALIR) with valve is studied. The impedances of the valve with different opening degrees are calculate by combined one/three-dimensional method. A lumped model is established to investigate the acoustic performance of the ALIR. Then the ALIR is applied into a kind of dual mode muffler, the acoustic property of which is investigated by experiment and numerical simulation. It is found that the resonance frequency shift towards high frequency as the valve's opening degrees increase, and the ALIR unit in the dual model muffler is not subject to the effect of coupling with other structural units. Furthermore, a verification test is implemented with the muffler installed in an actual vehicle. The results show that the dual model muffler can effectively eliminate the order noise tracing the engine speed times, which greatly improve the sound quality of vehicle exhaust noise.
展开▼
