WEST-EAST HIGH SPEED FLOW FIELD CONFERENCE 19-22, November 2007 Moscow, Russia PREDICTION OF INCOMING TURBULENT NOISE USING A COMBINED NUMERICAL / SEMI-EMPIRICAL METHOD AND EXPERIMENTAL VALIDATION

The present paper investigates the case of an airfoil placed in a turbulent jet. The Reynolds number based on the chord length is equal to 36,000 and the Mach number to 0.04. The unsteady, threedimensional incompressible flow around the airfoil is first computed with the LES module of the commercial solver FLUENT. An innovative procedure is then proposed to compute from the CFD computation, the noise radiated for the all frequency spectrum. The SYSNOISE solver, integrating Curle’s analogy limited to the computation of sound radiated by compact sources, is used to predict the low frequency part of the noise spectrum from the unsteady pressure fluctuations on the airfoil stored during the CFD flow computation. Then, Amiet’s theory, specially developed for airfoil sound radiation at high frequency, is taking into account, in an explicit way, non-compactness effects. The statistical flow data, needed by Amiet’s model, are fitted on the CFD data.