Experimental Study on the Turbomachinery Trailing Edge Noise Reduction Based on Linear Cascade Test with Phased Array

2015 ◽  
Author(s):  
Weiyang Qiao ◽  
Liangfeng Wang ◽  
Weijie Chen ◽  
Fan Tong ◽  
Liang Ji
Keyword(s):  
Experimental Study ◽  
Noise Reduction ◽  
Phased Array ◽  
Trailing Edge ◽  
Linear Cascade ◽  
Trailing Edge Noise

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.

Benefits of curved serrations on broadband trailing-edge noise reduction

2017 ◽  
Vol 400 ◽  
pp. 167-177 ◽  
Author(s):  
F. Avallone ◽  
W.C.P. van der Velden ◽  
D. Ragni
Keyword(s):  
Noise Reduction ◽  
Trailing Edge ◽  
Trailing Edge Noise

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

Experimental study of wavy trailing edge serrations on flat rotor blades

2021 ◽  
Vol 263 (5) ◽  
pp. 1855-1866
Author(s):  
Sai Manikanta Kaja ◽  
K. Sriinivasan ◽  
A. Jaswanth Kalyan Kumar
Keyword(s):  
Experimental Study ◽  
Noise Reduction ◽  
Pitch Angle ◽  
Acoustic Emissions ◽  
Broadband Noise ◽  
Rotor Blades ◽  
Tonal Noise ◽  
Trailing Edge ◽  
Low Speeds ◽  
Trailing Edge Serrations

A detailed experimental study is conducted to observe the effect of various parameters like wavelength, depth of serrations, and pitch angle on serrated blades' acoustic emissions at low speeds up to 2000 rpm. Experiments are conducted on flat blade rotors with sinusoidal serrations on the trailing edge of blades with different amplitudes and wavelengths. A total of 7 blades with different serration configurations, including a base configuration, are studied, five of them have serrations throughout the span of the blade, and one configuration has serration of varying amplitude on the farther half of the blade. It is observed that some blade configurations have resulted in tonal noise reduction noise as much as 8dB, whereas some of the serration configurations reduce very little to none, there is no significant effect of T.E serrations on the broadband noise emitted by the rotor. Directivity of noise generated from the rotor, the effect of serrations on the directivity of the noise is studied.

Airfoil Trailing Edge Noise Reduction Using a Boundary-Layer Bump

2019 ◽  
Vol 105 (5) ◽  
pp. 814-826 ◽  
Author(s):  
Yuejun Shi ◽  
Seongkyu Lee
Keyword(s):  
Boundary Layer ◽  
Noise Reduction ◽  
Suction Side ◽  
Reynolds Numbers ◽  
Numerical Approach ◽  
Trailing Edge ◽  
Velocity Deficit ◽  
Trailing Edge Noise ◽  
Field Noise ◽  
High Reynolds

This paper presents a new idea of reducing airfoil trailing edge noise using a small bump in the turbulent boundary layer. First, we develop and validate a new computational approach to predict airfoil trailing edge noise using steady RANS CFD, an empirical wall pressure spectrum model, and Howe's diff raction theory. This numerical approach enables fast and accurate predictions of trailing edge noise, which is used to study the noise reduction from the bump for various airfoil geometries and flow conditions at high Reynolds numbers. Three types of bumps, the suction-side bump, pressure-side bump, and both-side bumps, are studied. The results show that all types of bumps are able to reduce far-field noise up to 10 dB compared to clean airfoils, but their impacts are diff erent in terms of the eff ective frequency range. Also, bumps with four diff erent heights are compared with each other to investigate the eff ect of the height of bumps on noise reduction. It is demonstrated that a bump causes velocity deficit within the boundary layer near the wall. This velocity deficit results in reduced turbulence kinetic energy near the wall, which is responsible for trailing edge noise reduction. Overall, this paper demonstrates the potential of a boundary-layer bump in trailing edge noise reduction and sheds light on the physical mechanism of noise reduction with boundary-layer bumps.

scholarly journals Novel Three-Dimensional Surface Treatments for Trailing-Edge Noise Reduction

AIAA Journal ◽  
2019 ◽  
Vol 57 (10) ◽  
pp. 4527-4535 ◽  
Author(s):  
Abbas Afshari ◽  
Ali A. Dehghan ◽  
Mahdi Azarpeyvand
Keyword(s):  
Noise Reduction ◽  
Three Dimensional ◽  
Surface Treatments ◽  
Trailing Edge ◽  
Trailing Edge Noise ◽  
Dimensional Surface

An experimental study of trailing edge noise from a heaving airfoil

2020 ◽  
Vol 147 (6) ◽  
pp. 4020-4031
Author(s):  
Teng Zhou ◽  
Xin Zhang ◽  
Siyang Zhong
Keyword(s):  
Experimental Study ◽  
Trailing Edge ◽  
Trailing Edge Noise

scholarly journals Uniform flow injection into a turbulent boundary layer for trailing edge noise reduction

2020 ◽  
Vol 32 (8) ◽  
pp. 085104 ◽  
Author(s):  
Máté Szőke ◽  
Daniele Fiscaletti ◽  
Mahdi Azarpeyvand
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Noise Reduction ◽  
Flow Injection ◽  
Uniform Flow ◽  
Trailing Edge ◽  
Trailing Edge Noise
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