Development of scalar dissipation rate based reaction rate models for the large eddy simulations of premixed flames

本项目旨在开发一种基于标量耗散率(SDR)的高效反应速率封闭方法，用于湍流预混火焰的大涡模拟(LES)。尽管基于SDR的封闭器已经很好地用于非预混火焰的雷诺平均纳维斯托克斯(RANS)模拟，但对于湍流预混火焰的RAN和LES来说，基于SDR的封闭器很少，而且到目前为止还没有关于它们在LES中的性能的详细评估。在这个项目中，将开发基于SDR的反应速率闭合，并通过显式过滤的直接数值模拟(DNS)数据的先验分析和大涡模拟计算中模型性能的后验评估来同时评估，在可获得实验数据的配置下。基于同时的先验和后验分析，将开发新的模型，并随后评估其性能。然后，最好的模型将在湍流预混火焰模拟的LES代码中实现。基于SDR的高效反应速率闭合将为在稀薄预混合模式下运行的可靠、清洁和经济高效的燃烧设备(例如火花点火发动机、稀薄预混合预汽化(LPP)工业燃气轮机燃烧室)提供基于CFD的强大设计工具。

This project aims to develop an efficient Scalar Dissipation Rate (SDR) based reaction rate closure for the Large Eddy Simulation (LES) of turbulent premixed flames. Although SDR based closures are well established for Reynolds Averaged Navier Stokes (RANS) simulations of non-premixed flames, they are rare for RANS and LES of turbulent premixed flames, and no detailed evaluation of their performance in LES is available so far. In this project, the SDR based reaction rate closures will be developed and simultaneously assessed by a-priori analyses of explicitly filtered Direct Numerical Simulation (DNS) data, and a-posteriori evaluations of model performances in LES calculations, in a configuration for which experimental data is available. Based on the simultaneous a-priori and a-posteriori analyses, new models will be developed and their performance will subsequently be assessed. The best models will then be implemented in a LES code for turbulent premixed flame modelling. An efficient SDR-based reaction rate closure will provide a robust CFD based design tool for reliable, cleaner and cost-effective combustion devices operating in lean premixed mode (e.g. Spark Ignition engines, Lean Premixed Pre-vaporised (LPP) industrial gas turbine combustors).