超声速燃烧凹腔质量交换特性的混合RANS/LES模拟

对超声速冷流及燃烧流条件下超燃冲压发动机火焰稳定凹腔的质量交换特性进行了研究.采用混合RANS/LES(Reynolds-averaged Navier-Stokes/large-eddy simulation)方法对非定常流场进行数值模拟,系统研究了凹腔结构参数和横向喷流燃烧放热对凹腔质量交换特性的影响.首次采用"原子追踪法"对化学反应流条件下的凹腔质量交换过程进行了刻画.结果表明:在冷流条件和燃烧流条件下,凹腔驻留时间均随长深比的增大而增加;凹腔后缘倾角对驻留时间的影响在冷流条件下比较显著,而在燃烧流条件下明显减弱;相同结构的凹腔,在燃烧流条件下的驻留时间相对于冷流条件明显减小. 

Hybrid RANS/LES simulation of mass exchange characteristics of cavity for supersonic combustion

Mass exchange characteristics of cavities for scramjet applications under supersonic cold and combustion flow were investigated.The hybrid RANS/LES(Reynolds-averaged Navier-Stokes/large-eddy simulation) approach was used to simulate numerically unsteady state flowfields.The influences of the cavity parameters and the combustion on the mass exchange characteristics were investigated systemically.The mass exchange process in the reactive flow was described for the first time by using atom-tracking method.The hybrid RANS/LES data suggest that longer cavities have a longer residence time both in cold and combustion flow.The aft wall angle has a significant influence on the residence time just in the cold flow.For the same cavity,residence time reduces obviously in the combustion flow as compared with that in the cold flow.