关键词: 火箭发动机喷管;烧蚀性能;喷管烧蚀计算

Abstract: The linings of throat and divergent section are usually made of different materials in the construction of many rocket nozzle.A increasing step due to the difference of ablative rates occurs at the conjunction during operation,so that,a ablative indentation appears downstream,which is called ablative "Step Effect".The value of the indentation is considerable.The mechanism of step effect is that as the supersonic gas flow collides to wall,the turbulent degree intensifies.Consequently, the aerothermo-chemical reaction and convective heat-transfer also intensify.The nozzle ablation calculation considering the step effect is based on the ablative calculated programs of throat and-divergent section Hning.The intensifing of turbulent diffusion and chemical reaction caused by the collision of gas flow can be directly modified in original program (for details refer to reference[2]). Meanwhile,the heat-flow in step effect area is calculated fay applying Reynolds simulation relation and method of integration in turbulent layer,by which Bartz formula of convective heat-flow in nozzle can be substituted it.In this paper the heat-flow calculation in step effect area is introduced in detail.

Key words: Rocket engine nozzle;Ablation property;Nozzle ablation calculation