标题： 壁面受限流动的湍流解析积分模拟 显示英文标题

标题： Turbulence-Resolving Integral Simulations for Wall-Bounded Flows

摘要： 湍流模型的物理保真度可以从部分解析波动中受益，但这通常伴随着计算成本的增加。 为了在壁面受限流动背景下探索这种权衡，本文引入了一种用于湍流积分模拟（TRIS）的框架，旨在通过二维、三分量表示的流动来高效解析最大的运动，该表示由速度和压力的瞬时法向积分定义。 使用从纳维-斯托克斯方程推导出的动量矩积分方程以及相对简单的封闭近似，在开通道（半通道）流动配置下，展示了具有定性真实大尺度结构的自我维持湍流的TRIS。 来自直接数值模拟（DNS）的证据表明，对于摩擦雷诺数在180到5200之间的湍流，TRIS理论上可以解析35-40%的湍流摩阻增强，且不随雷诺数出现显著的减小或增加。 当前的TRIS实现可以在单处理器上约1分钟内完成一个时间上的流动模拟，即使对于非常大的雷诺数也是如此。 该框架促进了预测统计与DNS数据的详细苹果对苹果比较。 在摩擦雷诺数为395和590的比较显示，TRIS生成了相对准确的流动表示，同时突出了需要改进封闭模型的差异。 开放通道流动的现有结果代表了TRIS作为一种新的壁面受限湍流建模方法的概念验证，激励将其扩展到更一般的流动配置，例如浸没物体上的边界层。 显示英文摘要

摘要： The physical fidelity of turbulence models can benefit from a partial resolution of fluctuations, but doing so often comes with an increase in computational cost. To explore this trade-off in the context of wall-bounded flows, this paper introduces a framework for Turbulence-Resolving Integral Simulations (TRIS) with the goal of efficiently resolving the largest motions using a two-dimensional, three component representation of the flow defined by instantaneous wall-normal integrals of velocity and pressure. Self-sustaining turbulence with qualitatively realistic large-scale structures is demonstrated for TRIS on an open-channel (half-channel) flow configuration using moment-of-momentum integral equations derived from Navier-Stokes with relatively simple closure approximations. Evidence from Direct Numerical Simulations (DNS) suggests that TRIS can theoretically resolve 35-40% of the turbulent skin friction enhancement for friction Reynolds numbers between 180 and 5200, without a noticeable decrease or increase as a function of Reynolds number. The current implementation of TRIS can match this resolution while simulating one flow through time in ~1 minute on a single processor, even for very large Reynolds numbers. The framework facilitates a detailed apples-to-apples comparison of predicted statistics against data from DNS. Comparisons at friction Reynolds numbers of 395 and 590 show that TRIS generates a relatively accurate representation of the flow, while highlight discrepancies that demonstrate a need for improving the closure models. The present results for open-channel flow represent a proof of concept for TRIS as a new approach for wall-bounded turbulence modeling, motivating extension to more general flow configurations such as boundary layers on immersed objects.