設計応用のための効率的な空力音予測法の検討

抄録

This work will mention about an efficient aerodynamical sound prediction technique based on the computational fluid dynamics. The aerodynamical sound can be evaluated by the CFD (Computational Fluid Dynamics) technique to solve the full system of fluid dynamics equations. However, such computations often require huge computation costs caused by difference of characteristic speed between sound wave motion and variations of flow fields, and its unsteady computational approach. It seems to be a hindrance of application of CFD approach for aerodynamical sound predictions to the practical industrial design work. Present work proposes a numerical model for evaluation of sound power distribution use with the turbulence energy and the vorticity distributions which can be computed by only steady state CFD computations to reduce the computation cost. Proposed model is based on the Proudman’s idea. The model is applied to noise level predictions of ten different shape fans, then the variation of noise level between fans are predicted and compared with experimental observations. Present model can provide more accurate results compare with similar previous model.