LES Modeling for Turbulent Combustion Flows Based on Flamelet approach

针对当前能源和环境问题的局限性，本研究旨在发展一种新的基于大涡模拟（LES）和火焰面方法的湍流燃烧数值模拟模型，并将其应用于满足下一代能源设备严格要求的工业燃气轮机和车用发动机的流动优化设计。本研究从多尺度物理学的角度进行了研究：1）对数值方法进行了改进，使之能够更好地模拟工业问题中的实际几何形状和工况; 2）对非均匀非预混湍流火焰进行了新的数值模拟; 3）研究了火焰中的细节现象及其与颗粒的相互作用。主要研究结果如下：1）基于火焰面方法建立了湍流燃烧流场的大涡模拟。结合预混火焰的G方程模型和扩散的守恒标量模型，提出了非预混湍流火焰的双标量小火焰模型。B）研究了基本喷射面上流动脉动与燃烧的相互作用。通过大涡模拟和实验研究了喷雾运动、蒸发和化学反应的细节现象，探索了喷雾运动、蒸发和化学反应的各个基本过程。将“视觉融合技术”应用于喷雾分析，开发了基本的可视化系统，将数值模拟的图形结果和实验可视化结果以三维动画的形式结合起来，并进行交互处理。

In recent energy and environmental problems under the conscious of their limitation, this research aims to develop a new numerical simulation modeling for turbulent combustion flows based on a large eddy simulation (LES) and a flamelet approach to apply it to an optimal flow design in the industrial gasturbines and vehicle engines which cover the strict requirement for next gereation energy equipment. In this research, multi scale physics were investigated ; 1) the numerical method was improved for the large scale simulation of actual geometry and condition at the industrial problems, 2) Numerical modeling was newly developed for inhomogeneous non-premixed turbulent flames, 3) detail phenomena in the flame and its interaction to particles are investigated. The following results were obtained ;a) LES modeling for turbulent combustion flow was developed based on flamelet approach. Combing G-equation model for premixed flame and conservation scalar model for diffusion one, 2-scalar flamelet model was newly proposed for non-premixed turbulent flames. The model was validated on the turbulent combustion of industrial gasturbine combustor.b) Interaction of flow fluctuation and combustion was investigated on the basic spray banner. Detail phenomena of spray motion, vaporization and chemical reaction were investigated by LES and experiment for probing the models in each essential process.c) Fusion of numerical simulation and experiments was investigated. "Vsual fusion techniques" were applied to the spray analysis, where the basic visual system was developed for combining the graphics results of numerical simulation and visualization in experiment in three-dimensional animation and the interactive processing.