论文标题
确定非平衡流中边界层厚度的一般方法
General method for determining the boundary layer thickness in nonequilibrium flows
论文作者
论文摘要
尽管对于规范平衡流，但边界层厚度的计算很简单，但对于一般的非平衡流，尚无确定的定义。在这项工作中，基于对“ Inviscid”速度配置文件$ u_i [y] $的局部重建而开发了一种方法，这是由于bernoulli方程在壁正态方向上的应用而产生的。然后将边界层厚度$δ_{99} $定义为$ u/u_i = 0.99 $的位置，这与其对零压力级别边界层（ZPGBLS）的经典定义一致。所提出的局部重建方法是无参数的，可以在内部和外部流中部署，而无需诉诸迭代过程，数值集成或数值差异化。通过将这些方法应用于层流和湍流边界层以及两个流动的流动，可以证明局部重建方法的出色性能优于各种现有方法。数值实验表明，与现有方法相比，局部重建方法更准确，更健壮，并且适用于雷诺数范围的流量。
While the computation of the boundary-layer thickness is straightforward for canonical equilibrium flows, there are no established definitions for general non-equilibrium flows. In this work, a method is developed based on a local reconstruction of the "inviscid" velocity profile $U_I[y]$ resulting from the application of the Bernoulli equation in the wall-normal direction. The boundary-layer thickness $δ_{99}$ is then defined as the location where $U/U_I = 0.99$, which is consistent with its classical definition for the zero-pressure-gradient boundary layers (ZPGBLs). The proposed local-reconstruction method is parameter free and can be deployed for both internal and external flows without resorting to an iterative procedure, numerical integration, or numerical differentiation. The superior performance of the local-reconstruction method over various existing methods is demonstrated by applying the methods to laminar and turbulent boundary layers and two flows over airfoils. Numerical experiments reveal that the local-reconstruction method is more accurate and more robust than existing methods, and it is applicable for flows over a wide range of Reynolds numbers.
