TY - GEN
T1 - Effect of porous surface on the flat plate self-noise
AU - Bae, Youngmin
AU - Jeong, Ye Eun
AU - Moon, Young J.
PY - 2009
Y1 - 2009
N2 - In this study, the effect of porous surface on the turbulent noise generated by a blunt trailing-edge of a flat plate is investigated. The three-dimensional turbulent flow over the flat plate (Rec=1. 3×105 and M=0.06) is computed by incompressible large eddy simulation (LES) based on the volume-averaged Navier-Stokes equations, while the acoustic field is calculated by the linearized perturbed compressible equations (LPCE) coupled with LES solutions. The porous surface is applied to a small, selected area near the trailing-edge, where the Kármán vortex shedding and eddy scattering produce dipole sounds. The computed results show that the trailing-edge with porosity ε=0.25 and permeability (normalized) K*=0.01 yields a reduction of tonal peak by 13dB for zero angle of attack (α=0°), via breaking not only in the streamwise direction but also in the spanwise direction the spatial correlation of the wall pressure fluctuations (Rpp) near the trailing-edge. For the separated flow case (α=5°), the same configuration of the porous surface is found to weaken the pressure fluctuations at the trailing edge. It results in 3-10dB noise reduction over a wide range of frequency, via reducing the separated flow region over the upper surface of the plate.
AB - In this study, the effect of porous surface on the turbulent noise generated by a blunt trailing-edge of a flat plate is investigated. The three-dimensional turbulent flow over the flat plate (Rec=1. 3×105 and M=0.06) is computed by incompressible large eddy simulation (LES) based on the volume-averaged Navier-Stokes equations, while the acoustic field is calculated by the linearized perturbed compressible equations (LPCE) coupled with LES solutions. The porous surface is applied to a small, selected area near the trailing-edge, where the Kármán vortex shedding and eddy scattering produce dipole sounds. The computed results show that the trailing-edge with porosity ε=0.25 and permeability (normalized) K*=0.01 yields a reduction of tonal peak by 13dB for zero angle of attack (α=0°), via breaking not only in the streamwise direction but also in the spanwise direction the spatial correlation of the wall pressure fluctuations (Rpp) near the trailing-edge. For the separated flow case (α=5°), the same configuration of the porous surface is found to weaken the pressure fluctuations at the trailing edge. It results in 3-10dB noise reduction over a wide range of frequency, via reducing the separated flow region over the upper surface of the plate.
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U2 - 10.2514/6.2009-3311
DO - 10.2514/6.2009-3311
M3 - Conference contribution
AN - SCOPUS:78149438647
SN - 9781563479748
T3 - 15th AIAA/CEAS Aeroacoustics Conference (30th AIAA Aeroacoustics Conference)
BT - 15th AIAA/CEAS Aeroacoustics Conference (30th AIAA Aeroacoustics Conference)
PB - American Institute of Aeronautics and Astronautics Inc.
ER -