Multiscale Turbulent Reacting Flows and Data-Based Modeling

多尺度湍流反应流和基于数据的建模

• 批准号: 1217200
• 负责人: Tarek Echekki
• 金额: $ 20万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1217200&HistoricalAwards=false
• 关键词: Multiscale; Turbulent; Reacting; Flows; Data

This research project investigates a multiscale flame-embedding approach for the computation of turbulent flames. The model is based on the coupling of large-eddy simulation (LES) for the description of the flow and for flame tracking and embedded 1D stochastic solutions of flamelets based on the one-dimensional turbulence (ODT) model. Important features of the framework include the upscaling of ODT solution to the LES, the downscaling of LES solutions to ODT, and capturing of the flame front. The Lagrangian LES-ODT formulation requires the tracking, spawning, and removal of ODT solutions as they are advected along the flame. The formulation also requires a robust formulation for the filtering of the density from the fine-grained solution of ODT to the LES along with the filtering of transport and source terms for scalars used to track the flame in LES. Wavelet-based methods will be investigated to establish consistency between the LES and ODT velocity fields and their transport. An optimal parameterization of the thermo-chemical scalars using principal component analysis will be used to improve computational efficiency. This research addresses the prediction of physical processes occurring in the production of energy through combustion. The work aims to develop next-generation modeling tools that can potentially reduce the turn-around time for the design of combustion systems through simulation and to investigate mechanisms to improve combustion efficiency and reduce pollutants.

本研究计画探讨多尺度火焰嵌入法来计算紊流火焰。该模型是基于耦合的大涡模拟（LES）的描述的流动和火焰跟踪和嵌入的一维随机解的火焰的基础上的一维湍流（ODT）模型。该框架的重要功能包括升级的ODT解决方案的LES，规模缩小的LES解决方案的ODT，和捕捉的火焰前锋。拉格朗日LES-ODT制定需要跟踪，产卵，并删除ODT解决方案，因为它们是平流沿着火焰。该制剂还需要一个强大的配方过滤的密度从细粒度的解决方案的ODT的LES沿着与过滤的传输和源项标量用于跟踪LES中的火焰。将研究基于小波的方法，以建立LES和ODT速度场及其运输之间的一致性。使用主成分分析的热化学标量的最佳参数化将被用来提高计算效率。这项研究解决了通过燃烧产生能量的物理过程的预测。这项工作的目的是开发下一代建模工具，可以通过模拟减少燃烧系统设计的周转时间，并研究提高燃烧效率和减少污染物的机制。