Effect of Cutting Trailing Edge Serration on Aerodynamic Noise of Airfoil

This paper investigated the effects of cutting trailing edge serration on airfoil aerodynamic noise based on the acoustic analogy method. Large eddy simulation (LES) was used to capture the transient near-field information of the airfoil, and the Ffowcs Williams Hawkings (FW-H) equation is employed to predict the far-field noise. The research subject is the NACA0012 airfoil, with the length and width of serration ranging from 0.01 to 0.03 and 0.02 to 0.04 times the airfoil chord length (c), respectively. Acoustic experimental data are used to validate the accuracy of the simulation method. The angle of attack of incoming flow is 0°, with Reynolds and Mach numbers of 6.6 × 106 and 0.147, respectively. The research indicates that within the specified parameter range, the noise reduction effect of the serration perpendicular to the incoming flow direction is proportional to both the height and width of the serration. The maximum noise reduction is 3.3 dB. The cutting trailing edge serration leads to an increase in the high-frequency component of the streamwise noise. In the presence of cutting trailing edge serration, the overall sound pressure level of the streamwise noise increases. Compared to embedded trailing edge serration, cutting trailing edge serration have a lower limited height in terms of noise reduction.