Kinetic Theory Method for Large Eddy Simulation of Turbulence

湍流大涡模拟的动力学理论方法

• 批准号: 9974289
• 负责人: Steven Orszag
• 金额: $ 18万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9974289&HistoricalAwards=false
• 关键词: Kinetic; Theory; Method; Large; Eddy

9974289In this work, we plan to explore and apply a fundamentally new approach to large-eddy simulation (LES) of turbulence, viz. the use of a Boltzmann kinetic level representation of the flow. Conventional approaches to LES are based on solving a system of modified Navier-Stokes equations at the continuum level. While such an approach has achieved many interesting results, it also encounters intrinsic difficulties (e.g. in providing faithful turbulent behavior at boundaries). Owing to recent successes with the lattice Boltzmann method, we believe there is significant potential in approaching the problem from a new angle. That is, we propose the use of the Boltzmann equation representation of fluid dynamics. Such a representation is not only suitable for describing particle motions, but may also be a useful way of studying large-scale fluid turbulence properties once some appropriate averaging procedure is constructed. In this work, we plan to carry out an extensive series of theoretical and computational studies of turbulence dynamics by formulating such a Boltzmann description. The specific tasks include model formulation, simulation results, memory and history effects, reformulation of wall models and boundary conditions, and initial applications to multiphase turbulent flows.The work to be done here may have long-lasting impact on our ability to simulate fluid flows in real-world systems. The huge range of eddy sizes in turbulence precludes direct solution of the flow equations at all scales for full-scale systems. The novelty of the lattice Boltzmann method is that it circumvents some of the intrinsic limitations of conventional computers in order to achieve realistic flow simulations. By coupling of this method to advanced ideas on large-eddy simulation, we expect to achieve progress that would not otherwise be possible on these difficult flow problems. In particular, the lattice Boltzmann method for large-eddy simulation allows the efficient formulation of near-wall boundary conditions that have so far escaped analysis. It is also possible that the new formulations to be established here will suggest new computer architectures that will enable full-scale flow simulations.

9974289在这项工作中，我们计划探索并应用一种全新的湍流大涡模拟（LES）方法，即。使用玻尔兹曼动力学水平表示流动。 LES 的传统方法基于在连续体水平上求解修正的纳维-斯托克斯方程组。 虽然这种方法取得了许多有趣的结果，但它也遇到了内在的困难（例如，在边界处提供忠实的湍流行为）。 由于格子玻尔兹曼方法最近取得的成功，我们相信从新角度解决该问题具有巨大的潜力。 也就是说，我们建议使用流体动力学的玻尔兹曼方程表示。这种表示不仅适合描述粒子运动，而且一旦构建了一些适当的平均程序，也可能成为研究大规模流体湍流特性的有用方法。 在这项工作中，我们计划通过制定这样的玻尔兹曼描述来开展一系列广泛的湍流动力学理论和计算研究。 具体任务包括模型制定、模拟结果、记忆和历史效应、壁面模型和边界条件的重新制定，以及多相湍流的初步应用。这里要做的工作可能会对我们模拟现实系统中流体流动的能力产生长期影响。 湍流中涡流尺寸的巨大变化使得无法直接求解全尺度系统的所有尺度的流动方程。 格子玻尔兹曼方法的新颖之处在于它规避了传统计算机的一些固有局限性，以实现真实的流动模拟。 通过将该方法与大涡模拟的先进思想相结合，我们期望在这些困难的流动问题上取得原本不可能取得的进展。 特别是，用于大涡模拟的格子玻尔兹曼方法可以有效地制定迄今为止尚未进行分析的近壁边界条件。 这里建立的新公式也可能会提出新的计算机架构，从而实现全面的流动模拟。