论文标题
近增长近似，用于墙壁结合的湍流的近壁贴片表示
Slow-growth approximation for near-wall patch representation of wall-bounded turbulence
论文作者
论文摘要
已知壁构成的湍流表现出通过大规模流量结构调节的通用小规模动力学。但是，强压梯度使这种表征变得复杂。它们可能在流向方向上引起平均流量的显着变化。对于这种情况，我们对Navier-Stokes方程进行渐近分析，以告知模型，以使平均流量生长对位于边界的小域中的近壁湍流的影响。每当粘性长度尺度相对于平均流动变化的长度尺度较小时，渐近学是有效的。为了确保正确的动量环境，引入了动态过程，该过程解释了通过渐近术语引起的上层域边界的其他平均动量通量来源。比较该模型的低阶单点统计数据与直接数值模拟的统计数据以及对不良压力梯度湍流边界层的大型涡流模拟的比较表明，渐近模型成功地说明了边界层生长对小尺度的近壁湍流的影响。
Wall-bounded turbulent shear flows are known to exhibit universal small-scale dynamics that are modulated by large-scale flow structures. Strong pressure gradients complicate this characterization, however; they can cause significant variation of the mean flow in the streamwise direction. For such situations, we perform asymptotic analysis of the Navier-Stokes equations to inform a model for the effect of mean flow growth on near-wall turbulence in a small domain localized to the boundary. The asymptotics are valid whenever the viscous length scale is small relative to the length scale over which the mean flow varies. To ensure the correct momentum environment, a dynamic procedure is introduced that accounts for the additional sources of mean momentum flux through the upper domain boundary arising from the asymptotic terms. Comparisons of the model's low-order, single-point statistics with those from direct numerical simulation and well-resolved large eddy simulation of adverse-pressure gradient turbulent boundary layers indicate the asymptotic model successfully accounts for the effect of boundary layer growth on the small-scale near-wall turbulence.
