煤油/氧气同轴离心喷嘴燃烧数值模拟

为了更好地了解同轴离心喷嘴的工作特性,基于DDES模型研究了油气比分别为0.5、1、1.5下以煤油/氧气为推进剂的喷嘴的流体动力学特性与非预混燃烧特征。研究结果表明:由于旋流离心作用,在喷嘴出口轴心处和燃烧室顶部分别存在一个驻定涡和角涡,驻定涡径向分布在0.9 R~1.4 R,轴向尺寸在-1 R~14 R,随着燃料流量增大,驻定涡会向喷嘴内部推进,并且径向尺寸也会扩大。燃烧计算结果表明,随着燃料流量增大,推进剂的掺混拖曳区变长、掺混效果变好;而由于油气比的增加,燃烧室更加富油因此燃烧温度有所下降,同时火焰前锋向喷嘴内移。

Numerical simulation of kerosene/oxygen coaxial centrifugal injector combustion

In order to better understand the working characteristics of coaxial centrifugal nozzles,the hydrodynamic characteristics and non-premixed combustion characteristics of nozzles with kerosene/oxygen as propellant based on the DDES(delayed detached-eddy simlation)model with oil-gas ratios of 0.5,1,and 1.5 were studied.The research results show that due to the swirling centrifugal effect,there are a stationary vortex and an angular vortex at the nozzle outlet axis and the top of the combustion chamber,respectively.The stationary vortices are distributed in the radial direction from 0.9 R to 1.4 R and the axial dimension is-1 R~14 R,as the fuel flow increases,the stationary vortex will advance toward the inside of the nozzle,and the radial size will also expand.The combustion calculation results show that as the fuel flow increases,the propellant blending drag zone becomes longer and the blending effect is increased.However,due to the increase of the oil-gas mixing ratio,the combustion temperature decreases,and the flame front moves inward to the nozzle.