Abstract: CFD simulation is used to investigate the reactive flow field and NO_x distribution with steam addition for gas turbine combustor operations. The combustion model is laminar flamelet with a range of steam mass fractions. The detailed DLR-A nonpremixed turbulent flame was simulated to validate the RANS and combustion model employed in this study. Then the models are applied into the combustor configuration. The results show that the temperature would decrease and the size of the high temperature flame zone would be reduced when steam is added. Generally，the configuration of the flow field was not altered. Through comparing of the OH radical distribution，steam addition would promote the reaction. At take-off condition，the thermo-physical effects like reactant dilution and heat sink play a primary part for the heat reduction. The heat release induced by the reaction with steam addition is relatively small. When the steam mass fraction reaches as much as 15%，the NO_x emission could be reduced near by 95%.

Key words: Propulsion system；Combustor；Turbulent；Flow field

摘要： 为研究水蒸气的混入对实际工作条件下的涡轮发动机燃烧室流场及NO_x排放分布影响，采用Laminar flamelet燃烧模型对不同水蒸气含量下的煤油燃烧进行三维数值模拟。湍流及燃烧模型采用DLR-A湍流非预混射流火焰模型实验进行校验。燃烧室的计算结果表明，水蒸气的混入会减少燃烧室高温火焰燃烧区的尺寸和温度，流场的构型变化不大。通过OH基的组分分布及含量变化分析可知，在本文计算参数范围内，水蒸气会促使燃烧反应向下游移动。在起飞工作条件下，水蒸气进入燃烧室时其组分稀释及热沉为主要作用，化学反应的促进燃烧放热相对较小。当水蒸气的质量分数达到15%时，可减少约95%的NO_x排放量。

关键词: 推进系统；燃烧室；湍流；流场