Acoustic measurements were performed on single and multiple rod configurations to study the effect of Reynolds number, surface roughness, freestream turbulence, proximity and wake interference on the radiated noise. The Reynolds number ranged from 3.8 x 103 to 105. Directivity measurements were performed to determine how well the dipole assumption for the radiation of vortex shedding noise holds for the different model configurations tested. The dependence of the peak Sound Pressure Level on velocity was also examined. Several concepts for the reduction of the noise radiating from cylindrical rods were tested. It was shown that wire wraps and collar distributions could be used to significantly reduce the noise radiating from rods in tandem configurations.
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机译:对单杆和多杆配置进行了声学测量,以研究雷诺数,表面粗糙度,自由流湍流,接近度和尾流干扰对辐射噪声的影响。雷诺数范围为3.8 x 103到105。进行了方向性测量,以确定对于测试的不同模型配置,涡旋脱落噪声辐射的偶极假设保持得如何。还检查了峰值声压级对速度的依赖性。测试了几种减少圆柱棒辐射噪声的方案。结果表明,可以使用绕线和套环分布来显着降低串联配置中杆的辐射噪声。
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