Aeroacoustic shape optimization using adjoint sensitivity analysis based on lattice Boltzmann method for bluff bodies

The present study developed a shape optimization method using adjoint sensitivity analysis based on lattice Boltzmann method to suppress aerodynamically sound generation around bluff bodies. In this method, flow and acoustic fields are directly simulated using the lattice Boltzmann equation (LBE) with an athermal model under low-Mach-number conditions. The sensitivities of far-field sounds to numerous design variables that define an object shape can be evaluated by solving the adjoint equation, which is derived from the LBE. The adjoint equation can be computed easily and efficiently, similar to the LBM. The proposed method was applied to the cylinder Aeolian tone, and the cylinder shape was optimized.