Direct numerical simulation of self-noise of an installed control-diffusion airfoil

A study investigating the compressible flow around a controlled diffusion (CD) airfoil in a full anechoic open-jet facility is presented. The trailing edge noise sources of the CD airfoil and their propagation in the anechoic wind tunnel are simulated in a single step for the first time, using the Lattice Boltzmann Method (LBM) implemented in the PowerFlow solver. The LBM solves the time and space evolution of a discrete particle distribution function on a lattice grid. The method is naturally transient and compressible, and has been successfully applied to aero-acoustics problems at similar Reynolds number. Close to the reattachment point a turbulent boundary layer develops. When the curvature changes, the adverse pressure gradient leads to an increase of the boundary layer thickness. The non compacity of the source can be seen by the cardioid radiation pattern in the anechoic room.