突扩燃烧室湍流射流的相互作用及其对燃烧与混合的影响

Interactions of Turbulent Jets and Their Effects on Combustion andMixing in a Sudden Expansion Combustor

本文应用ｋ－ε湍流模型和快速化学反应的守恒标量简化ＰＤＦ模型，对有中心射流和环状射流相互作用的突扩燃烧室内的湍流流动、混合与扩散燃烧进行了数值模拟。研究了环状射流与中心射流的速度比在较大范围内改变时突扩燃烧室内湍流回流流场的变化，揭示了较大的射流速度比对突扩燃烧室内湍流混合与燃烧的强化作用。

The k ε turbulence model and the simplified PDF model of the conserved scalar for fast chemical reaction are employed in the present paper.The turbulent flow,mixing,and diffusion combustion in a sudden expansion combustor under the interactions of central jet and annular jet are numerically simulated.The effects of the velocity ratio of the two jets,varying in a large extent,on recirculation flow pattern in the combustor are delineated.It is shown that,under the large ratio of the velocity of the annular jet to that of the central jet,the mixing and combustion is greatly enhanced in the sudden expansion combustor.