Receptivity of a Supersonic Boundary Layer to Acoustic Disturbances
Receptivity of a Supersonic Boundary Layer to Acoustic Disturbances
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DOI：
10.2514/1.33395
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发表时间：
2009-05
期刊：
影响因子：
2.5
通讯作者：
P. Balakumar
中科院分区：
文献类型：
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作者：
P. Balakumar
对三维慢、快声扰动与钝化平板相互作用产生的边界层感受性过程进行了数值研究，在自由流马赫数为3.5、高雷诺数为39×106/m的情况下，在前缘附近设置和不设置二维孤立粗糙单元。定常解和非定常解均由求解完整的Navier-Stokes方程得到，空间离散采用五阶精度加权本质无振荡格式，时间积分采用三阶全变差递减Runge-Kutta格式。模拟结果表明，线性不稳定波产生的位置非常靠近前缘。边界层内扰动的波长首先逐渐增大，并在距前缘较近的范围内变得比不稳定波的波长长。然后波长逐渐减小，并与Tollmien-Schlichting波的波长合并。中性点附近不稳定波的初始幅度，即感受性系数，分别是慢波和快波自由流扰动幅度的1.20倍和0.07倍。研究还发现，对于给定的鼻钝度，孤立的小粗糙度元素并不能增强感受性过程。
The boundary layer receptivity process generated by the interaction of 3-D slow and fast acoustic disturbances with a blunted flat plate, is numerically investigated at a freestream Mach number of 3.5, and at a high Reynolds number of 39 * 10 6 /m. The computations are performed with and without a 2-D isolated roughness element located near the leading edge. Both the steady and unsteady solutions are obtained by solving the full Navier-Stokes equations using the fifth-order accurate weighted essentially nonoscillatory scheme for space discretization and using the third-order total-variation-diminishing Runge-Kutta scheme for time integration. The simulations showed that the linear instability waves are generated very close to the leading edge. The wavelength of the disturbances inside the boundary layer first increases gradually and becomes longer than the wavelength for the instability waves within a short distance from the leading edge. The wavelength then decreases gradually and merges with the wavelength for the Tollmien-Schlichting wave. The initial amplitudes of the instability waves near the neutral points, the receptivity coefficients, are about 1.20 and 0.07 times the amplitude of the freestream disturbances for the slow and fast waves, respectively. It was also revealed that a small isolated roughness element does not enhance the receptivity process for the given nose bluntness.