Development and Implementation of Practical Optimal LES Models

实用最优 LES 模型的开发和实施

• 批准号: 0352552
• 负责人: Robert Moser
• 金额: $ 2.76万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-15 至 2005-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0352552&HistoricalAwards=false
• 关键词: Development; Implementation; Practical; Optimal; LES

ABSTRACTPROPOSAL NO.: CTS-0352552PRINCIPAL INVESTIGATOR: ROBERT D. MOSERINSTITUTION: UNIVERSITY OF ILLINOIS, URBANA-CHAMPAIGNDEVELOPMENT AND IMPLEMENTATION OF PRACTICAL OPTIMAL LES MODELS In many technological devices, it is of great importance to predict and/or control the effects of turbulent fluid flows, because the behavior of the turbulence may ultimately control the performance of the device. Large eddy simulation (LES) is one of the most promising techniques for reliable prediction of the high Reynolds number turbulent flows of technological interest. In LES, the largest scales of turbulence are simulated while the effects of the smallest scales are modeled. However, there are a number of challenges to overcome for LES to realize its full potential; these include the treatment of near-wall turbulence and the impact of numerical discretization, especially in flows with complex geometries. The objective of the proposed research is to produce LES models that will provide reliable predictions in a broad range of turbulent flows. The approach is to apply the "Optimal LES" formulation, in which LES models are developed through a formal optimization process. Optimal LES models are formulated in terms of small separation multi-point velocity correlations. The primary remaining challenge in developing such models is obtaining the required velocity correlations, without resorting to extensive empirical data. The required statistical correlations will be developed using dynamic techniques, in which the correlations are estimated from the running simulation and from theoretical considerations. Of particular interest in the current project will be modeling near-wall turbulence, scalar transport and compressibility. The results of this development will be a broadly applicable and accurate LES modeling technique, which will be implemented in application CFD codes. Optimal LES will be developed into a powerful predictive tool in a wide range of turbulent flows. This will have great impact on many engineering applications in which turbulence is one of the dominant phenomena. Important examples are: flow in gas turbine engines, flow over multi-element high-lift airfoils, and flow in stirred tank reactors. With reliable LES simulations, these and many other applications will enjoy improved new designs, and reduced design costs arising from the decreased need for testing.

ABSTRACTPROPOSAL没有。作者：ROBERT D. moser研究机构：伊利诺伊大学香槟分校实用最优LES模型的开发与实现在许多技术设备中，预测和/或控制湍流流体的影响是非常重要的，因为湍流的行为可能最终控制设备的性能。大涡模拟（LES）是可靠预测高雷诺数湍流的最有前途的技术之一。在LES中，模拟了最大尺度的湍流，而模拟了最小尺度的影响。然而，低碳系统要充分发挥其潜力还需要克服许多挑战；这些包括近壁湍流的处理和数值离散化的影响，特别是在复杂几何形状的流动中。提出的研究目标是产生LES模型，该模型将在广泛的湍流中提供可靠的预测。该方法是应用“最优LES”公式，其中LES模型是通过正式的优化过程开发的。最优的LES模型是根据小分离多点速度相关性建立的。开发这种模型的主要挑战是在不依赖大量经验数据的情况下获得所需的速度相关性。所需的统计相关性将使用动态技术开发，其中相关性是从运行模拟和理论考虑中估计出来的。当前项目特别感兴趣的将是模拟近壁湍流、标量输运和可压缩性。这一发展的结果将是一种广泛适用和精确的LES建模技术，它将在应用CFD代码中实现。最优LES将发展成为大范围湍流预测的有力工具。这将对许多工程应用产生重大影响，其中湍流是主要现象之一。重要的例子是：燃气涡轮发动机的流动，多单元高升力翼型的流动，以及搅拌槽反应器中的流动。通过可靠的LES模拟，这些和许多其他应用程序将享受改进的新设计，并减少由于测试需求减少而产生的设计成本。