Effects of Slat Parameters on Features of Flow and Noise for an Airfoil

Abstract

Slat aerodynamic noise is largely dependent on its structure parameters(geometric position and variable outline). The analysis of the effects of these two parameters on the features of flow and aerodynamic noise for an airfoil is an effective method of developing techniques for the slat noise suppression. On the basis of three-element airfoil model 30P-30N, the flow field analysis model is established. The RANS and LES(large-eddy simulation) methods are used to analyze the steady and transient state flow field characteristics of the airfoils with typical geometric positions(overlap length, gap width and rotation angle) and morphed profiles(curved close gap of slat tailing edge respectively, which can obtain the corresponding distributions of pressure and turbulent kinetic energy of airfoil, and transient state pressure distribution of flow field. The FW-H acoustic analogy integral method is employed to solve the far-field noise distribution characteristic. The inter-relationship of various slat structure parameters with the far-field acoustic pressure level and its directional distribution features are investigated. According to various slat structure parameters, the coupling relationship between slat noise suppression and corresponding airfoil lift change is analyzed. The results show that the adjustment of slat geometry position and structural deformation parameters can effectively reduce the far-field noise radiation, but the lift coefficient can be reduced to some extent when the angle of attack is increased.

Keywords

• slat
• structure parameter
• flow field feature
• les
• aerodynamic noise