结合 VOF-RANS 方法研究粘性液体上初生风生波的演化
A combined VOF-RANS approach for studying the evolution of incipient wind-generated waves over a viscous liquid
AI总结：
本文提出结合流体体积（VOF）技术与二维雷诺平均 Navier-Stokes 方程及 Spalart-Allmaras 湍流模型的数值方法，用于研究不同风速与液体粘度下初生风生波的演化过程。
摘要：
最近的实验室实验表明，通过将携带液体的粘度改变几个数量级，可以获得关于风驱动的表面波生成所涉及的物理过程的重要见解。本文报告了一种配套方法的开发，旨在通过数值模拟研究类似现象。在回顾了现有选项后，我们选择并采用了一种基于流体体积（VOF）技术来追踪气液界面演化，并结合二维雷诺平均 Navier-Stokes 方程和湍流模型来预测两种流体中速度和压力场的方法。我们研究了该公式成立的数学与物理框架，并使用单方程 Spalart-Allmaras 模型闭合控制动量方程，该模型直接求解涡粘性的输运方程。为此，我们假设界面相对于空气中的湍流脉动表现为刚性壁面，并实现了一种通用算法来计算无论何种形状下到界面的局部距离。我们首先评估了该模型在波状刚性壁面流动的单相配置下的性能，这与风浪生成具有特定的相关性。然后，我们讨论了两相模拟中使用的初始化协议，该协议涉及应用于界面位置的白噪声分布。最后，我们展示了在不同风速和不同粘度液体下获得的界面演化示例。
英文摘要：
Recent laboratory experiments have revealed that important insights into the physical processes involved in the wind-driven generation of surface waves may be obtained by varying the viscosity of the carrying liquid over several orders of magnitude. The present paper reports on the development of a companion approach aimed at studying similar phenomena through numerical simulation. After reviewing available options, we select and approach based on the combination of a volume of fluid technique to track the evolution of the air-liquid interface, and a two-dimensional Reynolds-averaged version of the Navier-Stokes equations supplemented with a turbulence model to predict the velocity and pressure fields in both fluids. We examine the formal and physical frameworks in which such a formulation is meaningful, and close the governing momentum equations with the one-equation Spalart-Allmaras model which directly solves a transport equation for the eddy viscosity. For this purpose, we assume the interface to behave as a rigid wall with respect to turbulent fluctuations in the air, and implement a versatile algorithm to compute the local distance to the interface whatever its shape. We first assess the performance of this model in the single-phase configuration of flow over a wavy rigid wall, which is of specific relevance with respect to wind-wave generation. Then, we discuss the initialization protocol used in two-phase simulations, which involves a white noise distribution applied to the interface position. We finally present some examples of interface evolutions obtained at several wind speeds with liquids of various viscosities.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
