采用仿真软件GT-Power和Fluent的消声器声学和流场分析

Acoustics Performance Optimization for Mufflers Based on GT-Power and Fluent

某新车型怠速噪声严重超标,通过仿真软件GT-Power和Fluent仿真分析明确了消声器低频消声不足的原因及结构缺陷.提出了横流穿孔结构的前消声器结构,并改进了主消声器的穿孔形式. GT-Power仿真和试验结果表明,消声器低频消声性能得到提高,无载和带载怠速噪声分别降低超过4dB(A)和3dB(A),三挡全油门尾管总噪声及排气背压均满足技术要求.

The tailpipe idle noise of a new car model severely exceeds the manufacture s limits.The reason of inadequate low-frequency anechoic performance and structural imperfection are obtained by analyzing the transmission loss of the muffler and the muffler s interior flow field.The front muffler is optimized by using the cross-flow perforation structure and the main muffler s perforation form is improved.GT-Power simulation and test results show that low-frequency anechoic performance of the muffler is improved,and the tailpipe idle noise decreases by more than 4 dB(A)and 3 dB(A)respectively at AC off and AC on cases.The total tailpipe sound pressure levels and the back pressure of the exhaust system at the 3WOT case satisfy the manufacture s technical requirements.