Modeling of the Subgrid-scale Pressure-Strain-Rate Correlation in the Atmospheric Surface Layer

大气表层亚网格尺度压力-应变-速率相关性的建模

• 批准号: 1335995
• 负责人: Chenning Tong
• 金额: $ 33.13万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-15 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1335995&HistoricalAwards=false
• 关键词: Modeling; Subgrid; scale; Pressure; Strain

The research focuses on subgrid-scale modeling in large-eddy simulation (LES) of the atmospheric boundary layer (ABL). LES has become an effective research tool for the ABL and probably the most important simulation method for it. However, in the surface layer LES suffers from inherent under-resolution and poor subgrid-scale (SGS) model performance. This study will address this problem through analysis of field measurement data, modeling, and numerical simulations to improve SGS model performance.Issues in SGS modeling based on the SGS stress and flux transport equations will be analyzed. In particular, the focus will be put on modeling of the SGS pressure-strain-rate correlation, which is the main challenge in this modeling approach. Recent Advection Horizontal Array Turbulence Study (AHATS) field program has revealed new behavior of this variable as the cause of anisotropy in the SGS stress in the convective surface layer, contradicting the widely accepted understanding of its role of return to isotropy. With this knowledge, the physics of the SGS pressure-strain-rate correlation will further be investigated, and new transport equation models will be developed.Intellectual Merit:The research will address the critical issue of modeling the SGS pressure-strain-rate correlation in SGS stress transport equation-based SGS modeling for LES of the ABL. It is expected to significantly advance the understanding of the dynamics of the SGS stress and temperature flux. Due to the central role of the SGS pressure-strain-rate correlation in the SGS stress dynamics, new understanding of the physics of this correlation will have a profound impact on future SGS modeling. The model development activities will be a first step towards incorporating the new SGS physics into SGS models.Broader Impacts:The research has broader impacts in several areas. It will provide education and research opportunities for graduate and undergraduate students. Improved prediction of the surface layer turbulence and the ABL in general will be of importance to developing predictive models for atmospheric dispersion and diffusion, weather forecasting, atmospheric chemistry, wind energy, and land-atmosphere exchange. The modeling approach will also be important for modeling boundary layers with strong pressure gradient (e.g., curved boundary layers) in the ABL and in engineering flows. Advances in these areas will benefit the environment and society.

主要研究大气边界层大涡模拟(LES)中的亚网格尺度模拟。大涡模拟已成为反辐射导弹的有效研究工具，也可能是反辐射导弹最重要的仿真方法。然而，在近地面层，大涡模拟存在固有的分辨率不足和亚网格尺度(SGS)模式性能差的问题。本研究将通过现场测量数据的分析、建模和数值模拟来解决这一问题，以提高SGS模型的性能。分析基于SGS应力和通量输运方程的SGS模型存在的问题。特别是，重点将放在SGS压力-应变-速率相关性的建模上，这是该建模方法的主要挑战。最近的平流水平阵列湍流研究(AHATS)场程序揭示了这个变量的新行为，它是对流表层SGS应力各向异性的原因，与人们普遍接受的关于它返回各向同性的作用的理解相矛盾。有了这些知识，将进一步研究SGS压力-应变-速率相关性的物理机制，并开发新的输运方程模型。智力优势：该研究将解决基于SGS应力传输方程的ABL大涡模拟中SGS压力-应变-速率相关性建模的关键问题。这将极大地促进对SGS应力和温度通量动力学的理解。由于SGS压力-应变-速率关联式在SGS应力动力学中的核心作用，对这种关联式的物理意义的新认识将对未来的SGS建模产生深远的影响。模型开发活动将是将新的SGS物理学纳入SGS模型的第一步。更广泛的影响：这项研究在几个领域具有更广泛的影响。它将为研究生和本科生提供教育和研究机会。改进对近地层湍流和大气环流的预报将对发展大气扩散和扩散、天气预报、大气化学、风能和陆地-大气交换的预报模式具有重要意义。该建模方法对于模拟ABL中具有强压力梯度的边界层(例如，弯曲边界层)和工程流动也将是重要的。这些领域的进步将造福环境和社会。