Numerical prediction of aerodynamic sound by large eddy simulation (1st Report, Aerodynamic sound radiated from two-dimensional circular cylinder)

Aerodynamic sound radiated from the low-Mach-number turbulent wake of a circular cylinder has been numerically predicted by the following two-step approach. First, the three-dimensional unsteady incompressible Navier-Stokes equations are solved by the large eddy simulation (LES) technique using a streamline upwind finite-element method. The far-field sound pressure is then calculated from the fluctuating surface pressure on the cylinder, based on Curle's equation. A sophisticated method has been proposed for computing the SPL radiated from the entire span of the cylinder using the surface pressure fluctuation obtained in a small spanwise computational domain. The method takes the effects of random phase shift of the surface pressure fluctuation into account. The predicted SPL is compared with the measured value. Fairly good agreement has been achieved between the predicted and measured SPL's for the peak spectrum intensity and the frequency dependency of the sound pressure level up to about ten times higher than the peak frequency.