Numerical prediction of aerodynamic noise for light civil helicopter blade

Abstract

This paper presents numerical prediction of aerodynamic far-field noise on the main rotor blade of Light Civil Helicopter using CFD coupled with acoustic analogy code using numerical permeable surfaces. A chimera overset grid method is applied to the present simulation to consider the blade motion and moving effects. The permeable surface (Kirchhoff Integral Surface) enclosing both the physical blades and transonic flow regions is constructed to include the thickness noise, loading noise and the non-linear flow noise generated from the shock waves and tip vortices. The Kirchhoff approach is applied to Ffowcs Williams and Hawkings (FW-H) equations to efficient noise prediction in far-field and the total acoustic pressure with all noise sources is predicted.