Fundamental flame studies of turbulent premixed combustion

湍流预混和部分预混燃烧在大多数实际燃烧装置中遇到，例如燃气涡轮机、往复式发动机以及工业和家用燃烧器。在燃气轮机中，稀薄预混燃烧系统具有控制燃烧过程的内在吸引力，并且是选择的方法。完全预混系统提供对燃烧化学、反应动力学、火焰温度和污染物排放的控制。用于轻型车辆的先进直接喷射火花点火发动机中的预混合和部分预混合（分层）充气概念具有显著提高热效率的潜力。实验表明，湍流增加了预混合燃烧中的火焰传播速率。然而，这种效应背后的物理机制尚未完全被理解。其主要原因之一是湍流火焰传播显示出在其他湍流火焰中不常见的现象。在湍流预混火焰中，湍流、热力学和化学动力学的相互作用导致了高度复杂和令人费解的情况。因此，理论模型和计算研究远远不能解释实验观测结果，为了开发实际设备的贫油预混和部分预混燃烧概念的潜力，更好地理解基础物理是必不可少的。本提案的长期目标是提供湍流预混和部分预混燃烧领域的信息和新知识，这些信息和新知识可用作下一代燃气轮机和其他燃烧系统的设计工具。

Turbulent premixed and partially premixed combustion is encountered in most practical combustion devices such as gas turbines, reciprocating engines, and industrial and domestic burners. In gas turbines, lean premixed combustion systems have an intrinsic attraction for controlling the combustion process and are the methods of choice. Fully premixed systems provide control over combustion chemistry, reaction kinetics, flame temperatures, and pollutant emissions. Premixed and partially premixed (stratified) charge concepts used in advanced direct injection spark ignition engines for light duty vehicles have the potential for substantial thermal efficiency improvements.Experiments have shown that turbulence increases the flame propagation rates in premixed combustion. However, the physics behind this effect has not been fully understood yet. One of the leading reasons for this is that the turbulent flame propagation display phenomena that are not common in other turbulent flames. In turbulent premixed flames, interplay of turbulence, thermodynamics, and chemical kinetics leads to a highly complex and convoluted situation. As a result, theoretical models and computational studies are far from explaining the experimental observations.To exploit the potential of lean premixed and partially premixed combustion concepts for practical devices, a better understanding of the underlying physics is essential. The longer term objectives of this proposal is to provide information and new knowledge in the area of turbulent premixed and partially premixed combustion that can be used as tools in design of next generation of gas turbines and other combustion systems.