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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2018, Vol. 39 ›› Issue (1): 121469-121469.doi: 10.7527/S1000-6893.2017.121469

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

Analysis of mechanism of slat low frequency noise based on zonal DMD

WEI Jiayun1, LI Weipeng1, XU Siwei1, ZHAO Keliang2, SUN Yifeng2   

  1. 1. School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai 200240, China;
    2. Department of Overall Aerodynamics, Shanghai Aircraft Design and Research Institute, Shanghai 201315, China
  • Received:2017-06-01 Revised:2017-07-11 Online:2018-01-15 Published:2018-01-15
  • Supported by:
    National Natural Science Foundation of China (11202131, 11772194); National Basic Research Program of China (2014CB744802); Foundation of Shanghai Key Laboratory of Vehicle Aerodynamic and Vehicle Thermal Management Systems (VATLAB-2016-02)

Abstract: It is crucial to know the mechanism of low-frequency noise from the leading-edge slat, which can guide an advanced active and passive control of slat noise. According to the highly reliable Large Eddy Simulation (LES), this paper reveals the mechanism of slat noise using the method of Dynamic Mode Decomposition (DMD). The results indicate that the dipole features of slat noise come from the collision between large scale vortexes in the free shear layer and the lower surface of the slat. There is a close loop feedback mechanism of flow-acoustic coupling existing between large scale vortexes and low-frequency acoustic waves from the reattachment point. Based on this mechanism, a theoretical predictive model is also proposed and verified.

Key words: slat noise, large eddy simulation, dynamic mode decomposition (DMD), flow-acoustic coupling, closed-loop feedback

CLC Number: