Abstract:

Three bionic models were proposed by modifying the NACA 0018 airfoil model according to the serrated trailing edge and nonsmooth leading edge of owl wing, named serrated trailing edge model, scalloped leading edge model, serrated trailing edge and scalloped edge combining model. The aerodynamic noise generated by the three models is investigated by numerical simulation. The source fluctuations of the flow field are computed by Large-Eddy Simulation (LES). Then the fluctuations are fed to the followed acoustical computation as input data. The far-field sound level is computed by FW-H equations. The results at small angle-attack, α = 6° and at chord Reynolds number Re = 1.6×105 indicate that all three bionic models outperform the NACA 0018 airfoil model in aerodynamic noise reduction. The serrated trailing edge and scalloped leading edge combining model performs the best among the three models in noise reduction.

Key words: bionic engineering, airfoil, large-eddy simulation, aerodynamic noise