Prediction and control of trailing edge noise based on bionic airfoil

As a promising means, the passive porosity technology is used for the trailing-edge noise reduction of a bionic airfoil. The detailed two-dimensional Large Eddy Simulation is achieved to gain a better understanding of the prediction and passive control of trailing-edge noise source with the non-porous and porous treatment, respectively. The flow fields around the bionic airfoil indicate that the leading-edge separation causes both the noise contributors, i.e., the turbulent boundary layer and the vortex shedding. In addition, the effect of the porous trailing edge is substantiated in the distribution of the static pressure. The relevant noise also suggests a pronounced noise reduction potential in excess of 10 dB, but it has dependence on the flow resistivities. The two trailing-edge noise reduction mechanisms are characterized: (1) the suppression of the tonal vortex shedding noise; (2) the reduction of broadband turbulent boundary layer scattering noise. The findings may be used as reference in the design of silent aircraft.