An Active Network Representation to Predict the Flow Noise Characteristics of Corrugated Ducts

2008 ◽  
Vol 123 (5) ◽  
pp. 3129-3129
Author(s):  
Wim De Roeck ◽  
Vasilisa Solntseva ◽  
Wim Desmet
Keyword(s):  
Active Network ◽  
Flow Noise ◽  
Network Representation ◽  
Noise Characteristics

scholarly journals Study on flow noise characteristics of Bionic cylinder based on acoustic analogy

2021 ◽  
Vol 336 ◽  
pp. 01003
Author(s):  
Zixian Cui ◽  
Hao Song ◽  
Qi Li ◽  
Buchao An ◽  
Lin Su
Keyword(s):  
Noise Reduction ◽  
Reynolds Numbers ◽  
Wake Flow ◽  
Cylinder Surface ◽  
Acoustic Analogy ◽  
Fluctuating Pressure ◽  
Flow Noise ◽  
Noise Characteristics ◽  
Reduction Effect ◽  
Serrated Structure

The drag and noise reduction of the flow around a cylinder is one of the important topics in hydrodynamics and acoustics. In this paper, three typical bionic cylinders are designed based on the serrated structure on the surface of shark skin. Using Large eddy turbulence model and Lighthill’s acoustic analogy method, the flow noise characteristics of smooth cylinder and three kinds of bionic cylinders at different Reynolds numbers were compared, and the structure of cylinder surface was optimized. The results show that the main source of the flow noise around a cylinder is dipole noise, which is caused by the periodic fluctuating pressure on the cylinder surface.The bionic cylinder can reduce the amplitude of the fluctuating pressure, improve the wake flow field and reduce the wake vorticity, so as to reduce the noise. Among the three kinds of bionic cylinder, V-shaped bionic cylinder has the best noise reduction effect, and the critical value of S/H of V-shaped cylinder is about 2.5. When s / h > 2.5, V-shaped bionic cylinder has no effect of noise reduction.

Analysis of Hull-Induced Flow Noise Characteristics for Wave-Piercing Hull forms

2018 ◽  
Vol 24 (5) ◽  
pp. 619-627
Author(s):  
Woen-Sug Choi ◽  
◽  
Suk-Yoon Hong ◽  
Jee-Hun Song ◽  
Hyun-Wung Kwon ◽  
...  
Keyword(s):  
Flow Noise ◽  
Noise Characteristics ◽  
Induced Flow ◽  
Hull Forms

scholarly journals Flow field and noise characteristics of manifold in natural gas transportation station

2019 ◽  
Vol 74 ◽  
pp. 70 ◽  
Author(s):  
Zhongya Su ◽  
Enbin Liu ◽  
Yawen Xu ◽  
Ping Xie ◽  
Chen Shang ◽  
...  
Keyword(s):  
Natural Gas ◽  
Flow Field ◽  
Noise Reduction ◽  
Simulation Analysis ◽  
Fluid Dynamic ◽  
Acoustic Analogy ◽  
Pressure Balance ◽  
Expansion Chamber ◽  
Flow Noise ◽  
Noise Characteristics

Manifolds play a role of pressure balance, buffering and rectification for different branch pipelines, the flow noise of manifolds has been a serious problem all this time in natural gas transmission station. By changing the number of outlet pipes of manifolds and the different positions of intake pipes, the distribution of the Sound Pressure Level (SPL) of the manifold flow noise is analyzed based on the Ffowcs Williams-Hawkings (FW-H) acoustic analogy theory and Large Eddy Simulations (LESs). The three-dimensional simulation analysis of the flow field shows that pressure pulsation is the mainly source of manifold noise, as the number of outlet pipe increases, the SPLs of fluid dynamic noise at the end of inlet pipes are significantly reduced by about 10 dB on average, when the inlet and outlet piping are oppositely connected, the SPL is 2 dB~3 dB lower than that in staggered connections. An expansion-chamber muffler is designed with the analysis of its noise reduction effect, the results show that after the muffler is installed, the noise reduction in the low-frequency ranges reaches up to 37.5 dB, which controls the maximum noise to around 82 dB.

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