Aerodynamic sound from a sawtooth plate with different thickness

Abstract

Acoustic performance of an airfoil can be improved with the serrated leading or trailing edge. A sawtooth plate is one of the serration shapes. In this study, the effect of sawtooth plate thickness on the aerodynamically generated noise in wake-sawtooth plate interaction at a Reynolds number of 150 is numerically investigated. Two types of sawtooth plate thickness h_thick=0.2D and h_thin=0.02D are investigated. Flow simulations are carried out using direct numerical simulation and the noise calculations are solved using Curle’s equation. It is found that the wake-plate interaction is more prominent for the thicker plate. Consequently, the generated aerodynamic force is bigger for thick plate than the thin plate. Sound generated from the thin plate is approximately 0.34 dB lower than the thick plate. For the sound that is due to the quadrupole source gives ± -70 dB.

Keywords: Aerodynamic sound, Bluff body, Serrations, Acoustic analogy.