Experimental Investigation Into Trailing Edge Noise Sources

2006 ◽  
Author(s):  
Ana Garcia-Sagrado ◽  
Tom Hynes ◽  
Howard Hodson
Keyword(s):  
Experimental Investigation ◽  
Noise Sources ◽  
Trailing Edge ◽  
Trailing Edge Noise

Noise source location and scaling of subsonic upper-surface blowing

2020 ◽  
Vol 19 (3-5) ◽  
pp. 191-206
Author(s):  
Trae L Jennette ◽  
Krish K Ahuja
Keyword(s):  
Strouhal Number ◽  
Noise Source ◽  
Low Frequency ◽  
Directivity Pattern ◽  
Source Location ◽  
Dipole Source ◽  
Frequency Noise ◽  
Noise Sources ◽  
Trailing Edge ◽  
Trailing Edge Noise

This paper deals with the topic of upper surface blowing noise. Using a model-scale rectangular nozzle of an aspect ratio of 10 and a sharp trailing edge, detailed noise contours were acquired with and without a subsonic jet blowing over a flat surface to determine the noise source location as a function of frequency. Additionally, velocity scaling of the upper surface blowing noise was carried out. It was found that the upper surface blowing increases the noise significantly. This is a result of both the trailing edge noise and turbulence downstream of the trailing edge, referred to as wake noise in the paper. It was found that low-frequency noise with a peak Strouhal number of 0.02 originates from the trailing edge whereas the high-frequency noise with the peak in the vicinity of Strouhal number of 0.2 originates near the nozzle exit. Low frequency (low Strouhal number) follows a velocity scaling corresponding to a dipole source where as the high Strouhal numbers as quadrupole sources. The culmination of these two effects is a cardioid-shaped directivity pattern. On the shielded side, the most dominant noise sources were at the trailing edge and in the near wake. The trailing edge mounting geometry also created anomalous acoustic diffraction indicating that not only is the geometry of the edge itself important, but also all geometry near the trailing edge.

Trailing-edge noise reduction of a wing by a surface modification

2021 ◽  
Vol 263 (3) ◽  
pp. 3194-3201
Author(s):  
Varun Bharadwaj Ananthan ◽  
R.A.D. Akkermans ◽  
Dragan Kozulovic
Keyword(s):  
Noise Reduction ◽  
Stochastic Approach ◽  
Slight Reduction ◽  
Noise Sources ◽  
Trailing Edge ◽  
Sound Sources ◽  
Airframe Noise ◽  
Trailing Edge Noise ◽  
Random Particle ◽  
Noise Production

There is an increased emphasis on reducing airframe noise in the last decades. Airframe noise is sound generated by the interaction of a turbulent flow with the aircraft geometry, and significantly contributes to the overall noise production during the landing phase. One examples of airframe noise is the noise generated at a wing's trailing edge, i.e., trailing-edge noise. In this contribution, we numerically explore the local application of riblets for the purpose of trailing-edge noise reduction. Two configurations are studied: i) a clean NACA0012 wing section as a reference, and ii) the same configuration with riblets installed at the wing's aft part. The numerical investigation follows a hybrid computational aeroacoustics approach, where the time-average flow is studied by means of RANS. Noise sources are generated by means of a stochastic approach called Fast Random Particle Mesh method. The results show a deceleration of the flow behind the riblets. Furthermore, the turbulent kinetic energy indicates increased unsteadiness behind the riblets which is shifted away from the wall due to the presence of the riblets. Lastly, the sound sources are investigated by means of the 3D Lamb-vector, which indicates a slight reduction in magnitude near the trailing edge.

scholarly journals An experimental investigation of trailing-edge noise reduction due to elasticity

2018 ◽  
Author(s):  
Maurício M. Nilton ◽  
Yasir A. Malik ◽  
André V. Cavalieri ◽  
Leandro D. de Santana ◽  
Mauricio V. Donadon ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Noise Reduction ◽  
Trailing Edge ◽  
Trailing Edge Noise

scholarly journals Experimental investigation of trailing edge noise from stationary and rotating airfoils

2017 ◽  
Vol 141 (5) ◽  
pp. 3291-3301 ◽  
Author(s):  
Branko Zajamsek ◽  
Con J. Doolan ◽  
Danielle J. Moreau ◽  
Jeoffrey Fischer ◽  
Zebb Prime
Keyword(s):  
Experimental Investigation ◽  
Trailing Edge ◽  
Trailing Edge Noise

Experimental Investigation of the Trailing Edge Noise Mechanism

AIAA Journal ◽  
1978 ◽  
Vol 16 (10) ◽  
pp. 1046-1052 ◽  
Author(s):  
J. C. Yu ◽  
C. K. W. Tam
Keyword(s):  
Experimental Investigation ◽  
Trailing Edge ◽  
Trailing Edge Noise
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