当量比对铝粉/空气旋转爆轰发动机流场影响的数值模拟

Numerical simulations on effect of equivalence ratio on flow field inaluminum power/air rotating detonation engines

以铝粉为燃料,空气为氧化剂,通过一步反应机理,对不同当量比下气固两相旋转爆轰发动机的流场进行二维数值模拟研究。结果表明:由于颗粒注入速度和空气注入速度存在差异,导致反应物区中的颗粒三角区和空气三角区不完全重叠,使得当量比从0.6增加到1.4时,爆轰波前的平均局部当量比从0.929增加到2.093,爆轰波速度从2 070 m/s降低到1 690 m/s,爆轰波压力从5.67 MPa降低到4.87 MPa。燃烧室内基本的流场与气相旋转爆轰发动机相似,但气固两相之间的相互作用使得颗粒呈现出特有的分布特性,包括2个颗粒群和4条颗粒带以及它们之间的间隙。

The flow field of a gas-solid two-phase rotating detonation engine taking aluminum powder as fuel and air as oxidant with one step reaction was investigated by two-dimensional numerical simulations at different equivalence ratios.Results showed that the velocity of the detonation wave decreased from 2070 m/s to 1690 m/s and detonation pressure decreased from 5.67 MPa to 4.87 MPa when the equivalence ratio increased from 0.6 to 1.4,because the average local equivalence ratio increased from 0.929 to 2.093,which was caused by incomplete overlapping of trigonal zones between air and particles because of the injection velocity difference between air and particles.The flow field was similar to that in gas phase rotating detonation engines.However,unique distribution characteristics,including two particle groups,four particle bands and gaps among them due to the interaction between gas phase and solid phase,were obtained.