旋流燃烧室内冷态和热态流场的三维数值模拟分析

3-D Numerical Simulation Analysis of the Cold and Hot Flow Fields in a Swirl Combination Chamber

采用RNGk-ε湍流模型以及有限化学反应速率涡破碎模型(Eddy break up)对Allied Signal公司75 kW微型燃气轮机旋流燃烧室内冷态和热态时气流三维流动过程进行了模拟计算。结果表明,燃烧室火焰筒内热态时与冷态时的流场相似,烧室火焰筒内都有3个回流区,3个回流区的存在将有助于燃料的连续点火和火焰的稳定;燃烧室内热态三维流场的中心回流区长度小于冷态时的中心回流区长度,气流的轴向速度也大于相应的冷态轴向速度,而且掺冷孔空气射流对环向速度分布的影响小于冷态时的影响。

A simulative calculation was performed of the 3-d flow process of the cold and hot gas flows using the RNG k-ε turbulent flow model and the limited chemical reaction speed rate eddy break up model for the swirl combustion chamber of the 75kW micro-type gas turbine of Applied Signal Corporation. The result shows that the hot and cold flow fields in the flame tube of the combustion chamber are similar. There are three backflow zones in the flame tube of the combustion chamber, which benefit the continuous ignition of fuel and the stability of flame. The length of the central backflow zone of the hot 3-d flow field in the combustion chamber is shorter than that of the cold 3-d flow field, the axial velocity of the gas flow is also higher than that of the cold 3-d flow field, and the influence of air jet at the cold hole of the hot 3-d flow field on the circular velocity distribution is lower than that of the cold 3-d flow field.