论文标题
关于拟合通用的壁式图表的注释，用于建模大型涡流模拟
A note on fitting a generalized Moody diagram for wall modeled Large Eddy Simulations
论文作者
论文摘要
在壁上建模的大涡模拟（LES）的需求中，我们将拟合在其最简单的近壁，边界层近似（包括混合长度模型）的最简单的近壁，边界层近似中的雷诺平均navier-stokes方程的数值解。我们提出问题，使得独立的无量纲变量是直接在LE中可用的变量。我们为因变量提供实用的拟合，拟合粘性的子层和惯性对数层之间的平滑过渡，然后首先要进行进展，首先考虑中等压力梯度以及在假设混合长度不受压力梯度影响的假设下的粗糙度效应。考虑到压力梯度对湍流近壁结构的可能影响，还提供了基于镍的经验壁模型（J.流体机械，第512页，2004年）的替代拟合。然后，对于光滑和粗糙的表面，我们考虑了有利和不利的一般压力梯度的情况，直到分离的条件。所提出的拟合函数构成了广义的喜怒无常的图表，符合各种渐近方案有效的分析解决方案，并消除了在LES期间对普通微分方程的数值迭代溶液方法或近壁数值集成的需求。
Motivated by the needs of wall modeled Large Eddy Simulation (LES), we introduce fits to numerical solutions of the Reynolds Averaged Navier-Stokes equations in their simplest near-wall, boundary layer approximation including a mixing-length model. We formulate the problem such that independent dimensionless variables are those directly available in LES. We provide practical fits for the dependent variable, fits that encompass a smooth transition between the viscous sublayer and inertial logarithmic layer, and then progress first considering moderate pressure gradients as well as roughness effects under the assumption that the mixing-length is not affected by the pressure gradient. An alternative fit based on the empirical wall model of Nickels (J. Fluid Mech. vol.512, pp. 217-239, 2004) is also provided, taking into account possible effects of pressure gradient on turbulence near-wall structure. We then consider the case of general pressure gradients, both favorable and adverse, up to conditions of separation, for both smooth and rough surfaces. The proposed fitting functions constitute a generalized Moody chart, comply with analytical solutions valid in various asymptotic regimes, and obviate the need for numerical iterative solution methods or near-wall numerical integration of ordinary differential equations during LES.
