Reducing airfoil trailing-edge noise through chordwise-varying porous airfoil design

Abstract

A chordwise-varying porous wing design method is proposed in this paper. This method treats the porous wing as a perforated plate, and the turbulent boundary layer noise at the trailing edge of the wing is simulated using a quadrupole acoustic source. The sound field solution is obtained by employing the Mathieu function collocation method. We minimize the far-field noise by optimizing the porosity distribution of the perforated plate, thereby completing the design of the non-uniform porous wing. The comparisons with the finite element method results demonstrate the accuracy of the proposed method, while the comparisons with other porosity distribution perforated plates prove its effectiveness. The simulation results show that the porosity distribution based on the perforated plate model demonstrates noise reduction capabilities when applied to real wing structures. When the porosity is only 0.78%, the optimally perforated wing produces 2.2 dB less noise than a uniformly perforated wing and 2.8 dB less noise than an impermeable wing.