Direct aeroacoustic computation of exhaust mufflers flow noise

Exhaust flow noise simulation still remains a challenging activity because it requires computing two physical phenomena (turbulence and acoustic waves) with very different amplitude and length scales. For the past decade an innovative numerical method called “Lattice Boltzmann Method” has emerged as a very promising tool. Based on that numerical scheme, a recently developed software called LaBS (Lattice Boltzmann Solver) has been used to evaluate the noise generated by exhaust mufflers. Acoustic Results are presented for academic geometries and real mufflers. These numerical results are compared to experimental data measured on a cold flow bench for the same configurations. Acoustic broadband spectra comparison up to 10 kHz are presented and discussed.