掺混孔对中心分级燃烧室出口特性分析的数值模拟

Numerical Simulation of Influence of Dilution Holes on the Outlet Characteristics of Central Stage Combustor

燃烧室是航空发动机的核心部分,由于其出口工作环境复杂,研究分析其出口特性参数就显得尤其重要。针对中心分级燃烧室掺混孔几何特性方面对出口的影响,首先建立三级旋流器燃烧室的简化模型,再设计圆形、雨滴形、斜缝形3种掺混孔几何形状,利用FLUENT分析其各截面温度分布、速度场及NO x产物排放3个方面,并进行对比,经过模拟分析得雨滴形掺混孔对出口温度分布影响较好,圆形对燃烧室排放有着更好的调节作用。可见掺混孔对燃烧室出口特性有重要影响。

The combustor is the core of an aeroengine.It is particularly important to study the outlet characteristics because of its complex working environment.This paper focused on the influence the geometrical characteristics of dilution holes had on the outlet of a combustion chamber.A simplified model of a triple stage swirler combustor was established,and three kinds of dilution hole geometries as circular,raindrop and slit type were redesigned.The three aspects of temperature distribution,velocity field and pollutant NO x emission of each section were investigated by FLUENT.The simulation analysis shows that the dilution holes of raindrop type have a better effect on outlet temperature distribution,and the circular dilution holes have a better regulatory effect on pollutant emission.It can be concluded that the dilution holes have an important influence on the outlet characteristics of the combustion chamber.