Aerodynamic noise suppression of slats by using a SNGR method

Coupled with the turbulent velocity generation model and the sound propagation equation, a SNGR (Stochastic Noise Generation and Radiation) method which was able to simulate the noise source propagation in a non-uniform flow field was formed. In order to validate the SNGR method, the noise propagation of the 30P30N model's slat was selected. Comparing the frequency spectrum of the monitor at the trailing edge of the slat and the contour of noise directivity, numerical results are well consistent with the results in literature. Several different geometrical configurations of slats were designed. Adopting the SNGR method, the acoustic pressure contour and noise directivity contour of each configuration were analyzed, and the noise depressing effects were validated by means of the LES/FWH method. The result shows: 1. By extending the effective length of the leading edge of the slat, the stability of shear layer is strengthened and the intensity of the collision between shear layer and leeward region of slat is decreased. Because of these reasons, the noise of the slat is reduced. 2. The SNGR method can be applied to noise prediction and suppression of two-dimensional high-lift configurations.