污染对氢-空气燃烧影响的化学动力学分析

本文作了H_2O、O、H、OH和NO对氢-空气燃烧影响的化学动力学计算.计算范围是:压力0.02～0.2MPa,初始温度:910～2000K,当量油气比为1.0.有限速率化学反应模型包括38个反应式和13种组分的H_2-O_2-N_2系统,模型反应了氢-空气化学反应的当前最新研究成果.计算结果表明,在某些温度范围内,H_2O、O、H、OH和NO对着火时间有很大影响.反应时间并不受初始成份中自由原子和基的影响,但是初始成份中含有H_2O,将缩短反应时间.本研究关系到污染对燃烧的影响以及对于超音速燃烧冲压发动机地面试验的影响.燃烧化学动力学显然是污染影响中的一个重要因素.

CHEMICAL KINETICS ANALYSIS OF THE EFFECT OF VITIATED AIR ON COMBUSTION OF H2

Quantitative analysis have been conducted which show the effects of H2O, O, H, OH, NO on the finite-rate chemical kinetics of premixed hydrogen and air. Calculations were made over the pressure range of 0.02 to 0.2 MPa, over the temperatures range of 910 to 2000K, and at the hydrogen-air mixture equivalence ratio of 1.0. The finite-rate chemistry model includes 38 reactions among 13 species of the H2-O2-N2 system. The reactions contained in the mechanism reflect the current state of knowledge of the chemistry of the hydrogen-air system. The results indicate that the presence of H2, NO, O, H and OH can have significant effect on ignition time within certain mixture temperature. The reaction times is not affected by the initial amounts offree radicals, but is dominantly influenced by the H2O. This study deals with the effect of vitiated air contamination on combustion and scramjet engine ground tests. Combustion kinetics appears as the significant factor in a study on the effect of vitiation.