Three-Dimensional Simulation Analysis of the Influence of Slat Structural Parameters on Slat Aerodynamic Noise

缝翼结构参数对缝翼噪声影响的三维仿真分析

School of Aeronaustics, Northwestern Polytechnical University, Xi'an 710072, China

Received: 28 November 2018

Abstract

Slat aerodynamic noise is one of important components of the frame noise. Adjusting the parameters of the slat structure can suppress the slat noise radiation effectively. Based on the typical multi-element airfoil 30P30N, firstly, by means of adjusting the parameters of slat structure, such as changing relative positions between slat and main airfoil and closing slat gap etc., a new slat profile is obtained; Then, based on the DDES simulation method, the characteristics of vortex distribution is analyzed for the new airfoil structure model, and the directivity and SPL of the far field noise are also investigated; Finally, through comparison analysis of the parameters, the physics of the generation of slat aerodynamic noise is discovered, and effects of slat parameters on the features of slat aerodynamic noise are also obtained. The results of the study show that the vortex strength of the flow around the slat has close relation to the source of slat noise. By means of adjusting slat position parameters and morphing of the slat's trailing edge, the vortex strength of the flow close to the slat cusp is reduced effectively, and further largely reducing the slat noise radiation, which can be achieved with preserving high lift coefficient of the airfoil.

摘要

缝翼噪声是机体噪声的重要组成部分，调整缝翼结构参数可有效抑制缝翼噪声的辐射。针对典型多段翼型30P30N，首先，通过调整缝翼结构参数，如改变缝翼与主翼之间的相对位置、封闭缝翼通道等，以得到新的缝翼构型；其次，采用DDES方法计算三维瞬态流场，分析新构型下缝翼附近流场的涡量分布特性，以及利用FW-H积分方程获得远场噪声辐射的指向性和声压级分布特性；最后，通过参数对比分析，揭示缝翼辐射噪声的产生机理，并获得缝翼结构参数对噪声辐射特性的影响规律。研究结果表明：缝翼附近流场的涡量强度与缝翼噪声源有着紧密的联系；通过调整缝翼位置参数与缝翼后缘变形等方法，能有效降低缝翼前缘尖端附近流场的涡量强度，可在保持较高的升力系数的条件下，较大幅度降低缝翼噪声辐射。