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.

研究重点是大气边界层（ABL）大涡模拟（LES）中的亚网格尺度建模。 LES 已成为 ABL 的有效研究工具，并且可能是 ABL 最重要的模拟方法。 然而，在表面层，LES 存在固有的分辨率不足和亚网格尺度 (SGS) 模型性能不佳的问题。 本研究将通过分析现场测量数据、建模和数值模拟来解决这个问题，以提高 SGS 模型的性能。将分析基于 SGS 应力和通量输运方程的 SGS 建模中的问题。 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) 现场计划揭示了该变量的新行为，作为对流表面层 SGS 应力各向异性的原因，与广泛接受的对其返回各向同性作用的理解相矛盾。 有了这些知识，我们将进一步研究 SGS 压力-应变率相关性的物理原理，并开发新的传输方程模型。 智力优点：该研究将解决在基于 SGS 应力传输方程的 ABL LES 的 SGS 建模中对 SGS 压力-应变率相关性进行建模的关键问题。预计它将显着促进对 SGS 应力和温度通量动态的理解。 由于 SGS 压力-应变率相关性在 SGS 应力动力学中的核心作用，对这种相关性物理学的新理解将对未来的 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：该研究在多个领域产生更广泛的影响。 它将为研究生和本科生提供教育和研究机会。 改进对表层湍流和 ABL 的总体预测对于开发大气弥散和扩散、天气预报、大气化学、风能和陆地-大气交换的预测模型具有重要意义。该建模方法对于对 ABL 和工程流中具有强压力梯度的边界层（例如弯曲边界层）进行建模也很重要。这些领域的进步将有利于环境和社会。