关键词: 火箭, 级间热分离, 非定常数值模拟, 喷管流动分离, 横向喷流干扰

Abstract:

Based on the method of the unsteady axisymmetric NS equation coupled with one dimension separation dynamics equation, the initial phase of multi-stage rocket stage separation is numerical simulated. According to the simulation result, the two typical flow structures of initial phase of stage separation at low altitude are described: nozzle divergence dection flow separation inside the inter-stage area, interactive flow field of lateral jet flow impacting on the upstream incoming flow outside the inter-stage area. Time histories of flow separation position located on the upper stage (or in the nozzle) and wall pressure distribution are presented. The disturbance torques due to the tilted flow separation lines of both inside and outside flow are preliminarily estimated. The research firstly discovered that high pressure zone behind the flow separation shock of both inside and outside flow are the important sources of the disturbance imposed on the upper-stage by the staging action. The results can provide a direction for the research of stage separation disturbance mechanism and a reference for timing sequence design of stage separation.

Key words: Rocket, Stage separation, Unsteady numerical simulation, Nozzle flow separation, Lateral jet interaction