Fluid-acoustic interactions in self-sustained oscillations in turbulent cavity flows. I. Fluid-dynamic oscillations
Fluid-acoustic interactions in self-sustained oscillations in turbulent cavity flows. I. Fluid-dynamic oscillations
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DOI：
10.1063/1.3253326
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发表时间：
2009-10
影响因子：
4.6
通讯作者：
H. Yokoyama;C. Kato
中科院分区：
文献类型：
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作者：
H. Yokoyama;C. Kato
通过直接求解可压缩Navier-Stokes方程，研究了二维矩形空腔绕流中的流声相互作用。上游边界层是湍流的。空腔的深长比为0.5。相平均流场揭示了声辐射的机理。大尺度涡形成在剪切层中，从空腔的上游边缘分离。当大尺度旋涡与下游壁面碰撞时，旋涡中的低压流体沿着下游壁面扩散。结果，局部压力梯度引起局部向下速度，导致上游流体膨胀。最后，膨胀波传播到腔的外部。大尺度涡旋起源于切变层中发展的对流扰动。由于开尔文-亥姆霍兹不稳定性，扰动增长，类似于层流空腔流中的扰动增长。为了阐明产生的机制...
The fluid-acoustic interactions in a flow over a two-dimensional rectangular cavity are investigated by directly solving the compressible Navier–Stokes equations. The upstream boundary layer is turbulent. The depth-to-length ratio of the cavity is 0.5. Phase-averaged flow fields reveal the mechanism for the acoustic radiation. Large-scale vortices form in the shear layer that separates from the upstream edge of the cavity. When a large-scale vortex collides with the downstream wall, the low-pressure fluid in the vortex spreads along the downstream wall. As a result, a local downward velocity is induced by the local pressure gradient, causing the upstream fluid to expand. Finally, an expansion wave propagates to the outside of the cavity. The large-scale vortices originate from the convective disturbances that develop in the shear layer. The disturbances grow due to the Kelvin–Helmholtz instability, similar to the growth of those in a laminar cavity flow. To clarify the mechanism for the generation of the ...