Volume 39, Number 3, June 2021
|Page(s)||558 - 565|
|Published online||09 August 2021|
Study on characteristics of flow structure and generation of narrow-band in low-frequency noise for a slat
School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072, China
张巧(1995-), 女, 西北工业大学硕士研究生, 主要从事气动噪声控制与气动弹性研究。e-mail: firstname.lastname@example.org
Low-frequency narrow-band noise is one of the important components in the slat noise. Based on the transient flow field analysis for multi-element airfoil 30P-30N, the main mode characteristics of the slat pressure fluctuation are analyzed by means of proper orthogonal decomposition (POD) and dynamic model decomposition (DMD), and the key feature modes and the distribution of narrow-band frequencies for the slat are obtained. Empirical mode decomposition (EMD) and cross-correlation analysis are used to reconstruct the signal by preserving the low frequency characteristics of the original transient pressure signal. The locations of noise sources of the low-frequency narrow-band are determined according to the delay time and geometric relationship for characteristic points. The results show that the low-frequency narrow-band sound sources are mainly concentrated on regions of feature modes with large pressure fluctuations, such as slat trailing edge, downstream of the shear layer and the recirculation zone. Meanwhile, there are still some sound sources of low-frequency narrow-band distributed in regions of non-featured modes. The key characteristics of these regions are the interaction of flow structure between the trailing edge of the slat and the leading edge of the main wing due to collision of the shear layer.
Key words: POD / DMD / flow characteristics / aerodynamic noise / cross-correlation analysis
关键字 : POD / DMD / 流场特性 / 气动噪声 / 互相关分析
© 2021 Journal of Northwestern Polytechnical University. All rights reserved.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.