Airfoil Trailing-edge Noise Reduction using Flow Suction

Large eddy simulations were carried out for a NACA-0012 airfoil with trailing edge flow suction at the angle of attack = 0 for a chord-based Reynolds number of Rec = 4105. Simulations were performed with different flow suction rates to demonstrate the viability of the technique. The baseline case was thoroughly validated with experimental data. The aerodynamic and aeroacoustic characteristics of the boundary layer and wake were studied in detail for different flow suction rates. The mean velocity results showed reduced wake velocity deficit. Results have also shown that the suction of the boundary flow upstream of the trailing edge can reduce the boundary layer and wake turbulent kinetic energy and significant reduction of the wall pressure spectra near the trailing edge. The effect of flow suction on the spanwise correlation length has also been studied. The results have shown that a moderate flow suction rate can result in partial flow laminarization, broadband reduction of the surface pressure spectra and the radiated noise from the trailing edge.