Slat Noise Source Modeling of Multi-element Airfoil in High-lift Configuration

• Published in: International journal of aeronautical and space sciences Vol. 18; no. 2; pp. 197 - 205
• Main Authors: Hwang, Seung Tae, Han, Chang Kyun, Im, Yong Taek, Kim, Jong Rok, Bae, Youngmin, Moon, Young J
• Format: Journal Article
• Language: Korean
• Published: 2017
• Subjects: Simple source modeling; Computational aeroacoustics; Slat noise; 30P30N multi-element airfoil; Longitudinal vortex
• ISSN: 2093-274X; 2093-2480

We investigate the slat noise generation mechanism by using large-eddy simulation (LES) and simple source modeling based on linearized Euler equations. An incompressible LES of an MD 30P30N three-element airfoil in the high-lift configuration is conducted at $Re_c=1.7{\times}10^6$. Using the total derivative of the hydrodynamic pressure (DP/Dt) acquired from the incompressible LES, representative noise sources in the slat cove region are characterized in terms of simple sources such as frequency-specific monopoles and dipoles. Acoustic radiation around the 30P30N multi-element airfoil is effectively computed using the Brinkman penalization method incorporated with the linearized Euler equation. The directivity pattern of $p^{\prime}_{rms}$ at $r=20c_{slat}$ in the multiple sources is closely compared to that obtained by the application of the LES/Ffowcs-Williams and Hawking's methods to the entire flow field. The power spectrum of p' at ${\theta}=290^{\circ}$ is in good agreement with the data reported in BANC-III, especially the broadband part of the spectrum with a decaying slope ${\propto}f^{-3}$.