常出现于沙漠的沙丘引起的流场具有较好的稳定性和较小的阻力,为能够获得较小的总压损失以及稳定的驻涡区,文中在常规突扩燃烧室的基础上提出了一种新型的沙丘形燃烧室。采用Realizable k-ε湍流模型和二阶差分格式对该燃烧室内部流场进行了数值模拟,分析了在自然条件迎风角度和突扩比一定的条件下,不同背风角度对该燃烧器内冷态流场的影响。结果表明:存在一个最优的背风角度,使得总压损失较小而且内部驻涡稳定。研究结果对沙丘形燃烧器的设计具有指导意义。
The flow field caused by sand dunes of desert has better stability and less resistance. On the basis of conventional dump combustor,this paper proposed a new dune-shaped combustion chamber to reduce loss of total pressure and obtain stable trapped vortex. The internal flow field of this combustion chamber was simulated by Realizable k-ε turbulence model and second-order difference scheme. This paper discussed the influence of different leeward angles on cold flow field distribution of burner under certain windward angle and sudden expansion ratio of dune-shaped burners. There is an optimal leeward angle which makes the loss of total pressure be small and trapped vortex is stable. The results can instruct in the design of dune-shaped burner.