Three dimensional CFD analysis of slat noise

Three dimensional time accurate simulation based on the Reynolds-Averaged Navier-Stokes equations have been carried out. The unsteady dynamics of the slat flowfield and in particular the slat cove region has been predicted. 3D simulations of the slat cove flow over a computational model of 0.3 x 1m (0/3 m span and 1 m chord length) have improved the accuracy of the unsteady nearfield solution comparing the 2D calculations. The unsteady vorticity structures in the slat cove have been captured and the acoustic power level has been computed. Also a full acoustic scan over the slat surfaces and inside the cove region was conducted by the use of source models such as Proudman's formula and boundary layer noise source model. Analysis of the 3D result demonstrates the importance of the reattachment region for its turbulent fluctuations that enforce the generation of slat noise (broadband). The computed acoustic characteristics (in terms of the frequency spectrum) at receivers located at fixed distance from the slat model in the computational domain resemble the previously computed acoustic spectra of two dimensional calculations.