关键词: 声学测试；消声器；流场仿真；传递损失；氢燃料汽车

Abstract: In order to address the issue of exhaust noise in hydrogen fuel vehicles under high-power load conditions of fuel cell stacks, the acoustic performance of the muffler system is optimized through interactive analysis of acoustic testing and flow field simulation. Finite element method is used to simulate and analyze the turbulent kinetic energy of the internal flow field of the muffler, and acoustic testing methods are used to verify the transmission loss of the muffler. Research has found that the performance of the original state muffler is average in the mid frequency range and poor in the low and high frequency range. By establishing a flow field simulation model for the muffler, optimize its internal structure, including variable diameter air ducts, muffler lining, and shock absorber pads. The fluid simulation calculation results show that the turbulence kinetic energy in the fluid domain of the new muffler structure is significantly reduced, improving the turbulence phenomenon inside the muffler. The acoustic test results of the muffler show that the transmission loss of the new state muffler is significantly improved in the frequency range of 500~12 500 Hz, presenting a better noise reduction effect. The research results indicate that under high-power load full frequency operating conditions of the fuel cell stack, the combination of flow field simulation and acoustic testing can quickly optimize the muffler structure, improve the noise reduction performance in the full frequency range, and improve the comfort and user experience of the vehicle.

Key words: Acoustical testing; Muffler; Computational fluid dynamics; Transmission loss; Hydrogen fuel vehicles