Görtler instability of boundary layers over concave and convex walls
Görtler instability of boundary layers over concave and convex walls
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凹壁和凸壁边界层的戈特勒不稳定性
DOI：
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发表时间：
1986
期刊：
影响因子：
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通讯作者：
J. M. Floryan
中科院分区：
文献类型：
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作者：
J. M. Floryan
给出了曲面上边界层的稳定性分析。建立了一个简单的无粘性稳定性判据，并用于识别相对于Gortler型扰动潜在不稳定的剪切层。在凸面的情况下，如果速度值随着距离壁面的距离增加而增加，而在凹面的情况下，速度值减小，则流动是稳定的。因此，无论所考虑的表面类型如何，具有非单调速度分布的流动总是潜在的不稳定。当粘性稳定性理论应用于选定的边界层时，结果证实了基于无粘性理论的结论。对Blasius边界层(单调速度分布)和壁射流(非单调速度分布)进行了详细的计算。结果表明，单调速度分布的流动比非单调速度分布的流动更早变得不稳定。
The stability analysis of boundary layers over curved surfaces is presented. A simple inviscid stability criterion is developed and used to identify shear layers which are potentially unstable with respect to the Gortler‐type disturbances. A flow is stable if the velocity magnitude increases with distance away from the wall in the case of convex surfaces and decreases in the case of concave surfaces. The flows with nonmonotonic velocity distributions are therefore always potentially unstable regardless of the type of surface being considered. When viscous stability theory is applied to selected boundary layers the results confirm conclusions based on the inviscid theory. Detailed calculations are carried out for the Blasius boundary layer (monotonic velocity distribution) and a wall jet (nonmonotonic velocity distribution). Results suggest that flows with monotonic velocity distributions become unstable earlier than flows with nonmonotonic velocity distributions.