Direct numerical simulation of the self-noise radiated by installed controlled-diffusion airfoil at transitional reynolds number

Abstract

A 3D compressible direct numerical simulation is conducted of a controlled-diffusion airfoil at 8° angle of attack that is embedded in a wind-tunnel flow at an airfoil chord based Reynolds number of Rec = 150, 000 and at a Mach number of M = 0.25. Under these flow conditions, a short separation bubble is formed at the airfoil leading-edge on the suction side which triggers the laminar to turbulent transition of the flow. The flow remains turbulent and attached until the trailing-edge. On the pressure side, the flow stays laminar until the trailing-edge where minor vortex shedding originates due to the blunt (round) trailing-edge and then mixes with the turbulent flow from the suction side in..