In view of the problem of limitations on engine plume diversion

based on engineering experiences

four typical molding surfaces of diversion devices (including form of inner groove and form of diversion cone) were proposed to carry out numerical simulation of the aerodynamic and aerothermal effects caused by plume diversion during take-off using the coupling simulation method of computational fluid dynamics (CFD) and direct simulation of Monte Carlo (DSMC)

and analyze the plume field shock wave and spacecraft surface pressure and heat flow density distribution law

thereupon the evaluation on diversion effects of the four diversion devices was presented

and finally tests in the form of diversion core were conducted to verify the simulation algorithm. The result show that the engine is stable with the plume diversion

the scheme of the large diversion core is optimal considering the spacecraft plume and engine safety

the shock near the diversion core is the same as the simulation

the variation trend of simulation and test is consistent

the algorithm is credible and the law can be applied in engineering.