Abstract
The present paper shows the ability of Lattice Boltzmann method (LBM) to simulate flow and acoustic fields with low Mach number. Toward engineering applications which have complicated geometries and large computational domains, the computational method based on LBM using a Cartesian mesh was developed by the multi-scale model, the Building-cube method and a simple immersed boundary scheme. Furthermore, a low-pass filtering operator was used to suppress numerical instabilities caused by the use of low-resolution meshes. First, tonal noise generated from an airfoil in uniform flow was calculated by the isothermal model and the thermal model. The tone frequency and SPL of isothermal model show small differences from those of the thermal model. Secondary, broadband noise generated from a transitional boundary layer over an airfoil was simulated using the isothermal model. The computed frequency spectra of far-field sound agreed well with that of experimental data available in the literature.
