DOI: 10.1615/TSFP5
LARGE-EDDY SIMULATION OF THE FLOW AROUND A HIGH-LIFT AIRFOIL CONFIGURATION
摘要
To identify the flow phenomena generating slat noise, a large-eddy simulation (LES) of the flow around an airfoil consisting of a slat and a main wing is performed at a Reynolds number of 1.4 million based on the freestream velocity and the clean chord length. The freestream Mach number is Ma = 0.16 and the angle of attack is 13° deg. Sponge layers are used to avoid spurious reflections at the outer boundaries of the computational domain. A computational mesh with about 55 million cells are used to resolve the turbulent scales in the boundary layers and within the slat cove region. The comparison with experimental data shows acceptable agreement for the pressure and Mach number distribution. The detailed analysis of the external flow field reveals boundary layer transition. The turbulent structures of the slat cove shear layer are compared to those in a plane shear layer. The shear layer behavior in the reattachment region is assessed by the mechanisms of an impinging jet. It is shown that the major acoustic source, the perturbed Lamb vector, coincides with areas of high turbulent kinetic energy.