Experimental investigation of sound generation by a protuberance in a laminar boundary layer
Experimental investigation of sound generation by a protuberance in a laminar boundary layer
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层流边界层中突起发声的实验研究
DOI：
10.1063/1.4894011
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发表时间：
2014
影响因子：
4.6
通讯作者：
A. Inasawa
中科院分区：
文献类型：
--
作者：
M. Kobayashi;M. Asai;A. Inasawa
在低马赫数下，对层流边界层中粘贴在壁面上的二维突起物的声辐射进行了实验研究。当突起高度与边界层厚度相同时，突起产生的声音和前缘对上游传播声音的感受性产生的Tollmien-Schlichting（T-S）波之间存在反馈回路机制。虽然发生的分离气泡的突起的上游发挥了重要的作用，在不稳定波的演变成涡与突起相互作用，音调涡声的频率是由选择性放大的T-S波的线性不稳定阶段的分离气泡的上游，而不是由分离气泡的不稳定性。
Sound radiation from a two-dimensional protuberance glued on the wall in a laminar boundary layer was investigated experimentally at low Mach numbers. When the protuberance was as high as the boundary-layer thickness, a feedback-loop mechanism set in between protuberance-generated sound and Tollmien-Schlichting (T-S) waves generated by the leading-edge receptivity to the upstream-propagating sound. Although occurrence of a separation bubble immediately upstream of the protuberance played important roles in the evolution of instability waves into vortices interacting with the protuberance, the frequency of tonal vortex sound was determined by the selective amplification of T-S waves in the linear instability stage upstream of the separation bubble and was not affected by the instability of the separation bubble.