高马赫数下超声速燃烧的自点火查表方法

超燃冲压发动机燃烧室工作在高马赫数工况时, 入口来流空气的总焓非常高, 自点火在高焓条件下成为维持火焰稳定的重要物理化学过程. 本文借鉴火焰面/进度变量模型的降维思路, 发展了一种基于化学动力学的自点火建表方法. 通过定义混合分数和进度变量将复杂多维的化学反应降维, 并成功将数据库方法结合到现有的大涡模拟求解器中. 经过测试和验证, 该方法初步具备对超声速自点火燃烧进行仿真描述的能力. 针对自点火诱导的超声速燃烧问题开展数值模拟, 该方法通过查表的方式有效降低了化学反应求解过程中的计算量. 在采用详细化学反应机理时能够准确地再现自点火行为和火焰结构, 并且预测的温度和重要组分分布与实验吻合较好. 

AUTO-IGNITION TABULATED METHOD FOR SUPERSONIC COMBUSTION AT HIGH MACH NUMBER

When the scramjet combustor works under high Mach number conditions, the total enthalpy of the inlet air is very high, and auto-ignition becomes an important physical and chemical process to maintain flame stability. This paper develops an auto-ignition tabulated method based on chemical kinetics, referring to the dimensions reduction means of the flamelet/progress variable model. The complex and multi-dimensional chemical reactions is reduced by defining the mixture fraction and progress variables, and the database method is successfully integrated into the existing large eddy simulation solver. After testing and verification, the method possesses the ability to simulate and describe the supersonic auto-ignition and flame. Numerical simulation is carried out for supersonic combustion induced by auto-ignition in two configuration. This method effectively reduces the amount of calculation in the process of solving chemical reactions by looking up the database. When the detailed chemical reaction mechanism is used, the auto-ignition behavior and flame structure can be accurately reproduced, and the predicted temperature and the distribution of important components are in good agreement with the experiment.