Journal of Aeronautical Engineering

Journal of Aeronautical Engineering

Numerical study of the effect of rectangular finlets on the turbulent boundary layer trailing edge noise of a flat edge

Document Type : Original Article

Authors
Mohammad Farmani 1
aliakbar dehghan 2
milad zabihinezhad 3
1 Faculty of Mechanical Engineering, Yazd University, Yazd, Iran
2 Professor, Faculty of Mechanical Engineering, Yazd University, Yazd, Iran
3 PhD Student, Mechanical Engineering, Faculty of Mechanical Engineering, Yazd University, Yazd, Iran
10.22034/joae.2021.316457.1074
Abstract
In this study, the effect of rectangular finlets on the trailing edge noise of a flat plate in an incompressible turbulent boundary layer with Mach number 0.06 has been studied numerically. The finlets are modeled upstream of the trailing edge of the flat plate with two spanwise spacing of 1.5 and 0.9 mm. Large eddy simulation (LES) approach with Lund inflow generation model in open source code of OpenFOAM has been used to simulate the turbulent boundary layer flow. Probe utility has been used for pressure and velocity data acquisitions. The finlets have increased the PSD of pressure fluctuations in the low to mid frequencies and decreased it at high frequencies between and downstream of the finlets. Also, the spanwise length scale of the pressure fluctuations increases but the eddy convection velocity is reduced and their effects has intensified by the reduction of the spanwise spacing. The mean velocity decreases but the turbulence intensity increases downstream of the finlets. The reduction of the spanwise spacing of the finlets results in the formation of a stronger shear layer and the extension of the shear sheltering area downstream of the finlets. According to the results of the far-field noise prediction with Curle analogy, finlets with the spacing of 1.5 mm have slightly reduced the noise about 0.3dB but the finlets with the spacing of 0.9 mm have increased the trailing edge noise of the flat plate, about 1dB.
Keywords
Simulation
Finlet
Trailing edge noise
Turbulent boundary layer
Flat plate
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Journal of Aeronautical Engineering
Volume 23, Issue 2
December 2021
Pages 136-153

  • Receive Date 22 November 2021
  • Revise Date 10 December 2021
  • Accept Date 21 December 2021