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Numerical Modal Analysis of the Correlation Between Spanwise Vortex Shedding and Far-field Aeolian Noise for Square and Circular Wall-mounted Cylinders

عنوان مقاله: Numerical Modal Analysis of the Correlation Between Spanwise Vortex Shedding and Far-field Aeolian Noise for Square and Circular Wall-mounted Cylinders
شناسه ملی مقاله: JR_JAFM-18-2_011
منتشر شده در در سال 1404
مشخصات نویسندگان مقاله:

R. P. Jiang - Key Laboratory of Aero-Acoustics of Ministry of Industry and Information Technology, Beihang University, Beijing ۱۰۰۱۹۱, China
P. Q. Liu - Key Laboratory of Aero-Acoustics of Ministry of Industry and Information Technology, Beihang University, Beijing ۱۰۰۱۹۱, China
J. Zhang - Sino-French Engineer School, Beihang University, Beijing ۱۰۰۱۹۱, China
H. Guo - Key Laboratory of Aero-Acoustics of Ministry of Industry and Information Technology, Beihang University, Beijing ۱۰۰۱۹۱, China

خلاصه مقاله:
For square and circular finite wall-mounted cylinders (FWMCs) with an aspect ratio exceeding ۱۰, the vortex shedding near the tip area leads to the generation of multiple tonal noises. The quantitative analysis of the spanwise distributions of the vortex modal energy with different frequencies was quite limited. This study employs dynamic mode decomposition to decompose the wake of FWMC into distinct frequencies to evaluate the modal energy distribution of pressure fluctuations at each frequency along the spanwise direction. Large eddy simulation combined with the Ffowcs Williams–Hawkings (FW–H) acoustics analogy is applied to a square and a circular FWMC with aspect ratio of ۱۳.۶ at a Reynolds number of ۲.۳ × ۱۰۴. Two indicators to describe the spanwise energy contribution are proposed. The results reveal that, for square FWMC, the primary modal energy corresponding to Strouhal number ( St ) equal to ۰.۱۴ is concentrated below ۳۰% of the cylinder height  owing to the ۳D effect. A transition mode of  St ≈ ۰.۱۲ is identified in the midspan (۰.۳ L–۰.۷L ) without significant contribution to far-field noise spectrum. For circular FWMC, the modal energy is distributed over several frequencies, vortices cells corresponding to the main noise band (۰.۲
کلمات کلیدی:
Aeroacoustics, Finite wall-mounted cylinder, Dynamic Mode Decomposition, Spanwise energy distribution, Modal energy contribution

صفحه اختصاصی مقاله و دریافت فایل کامل: https://civilica.com/doc/2132368/