关键词: 火箭橇试验;火箭发动机;三维数值仿真;喷管流场;流场地面效应

Abstract: Based on the needs of the rocket skid ground test， the researcher design the short-track rocket sled power system with large load and high acceleration， and it is conducted the theoretical and experimental influence study of ground effect on the flow field of the rocket motor tail nozzle. The 3-D numerical simulation of the rocket motor tail nozzle outer flow field was conducted for different conditions using FLUENT calculation software. It analyzed the influence of ground effect on the flow field characteristics of the motor tail nozzle when a single rocket and two rockets are working. For the short-track rocket sled power system with large load and high acceleration studied in this paper， both the influence of ground effect and the interaction between the two nozzles which appeared at 1.5ms， was more obvious at 2~3ms， and decreased at 5~20ms， finally， a stable tail flow field is formed. For rocket sled power system， the nozzle outlet diameter is 275mm， the distance between the axis and the ground is not less than 472mm， and the distance between the axis of double nozzles is not less than 680mm. After the rocket sled move for 20ms， the effect of the ground and the interaction between the double rocket motors become very small.

Key words: Rocket sled test;Rocket motor;3-D numerical simulation;Nozzle flow field;Ground effect of flow field