Tactical Missile Technology

The effects on base drag change causing by jet of booster in the conditions of 0 ~ 35 km are studied numerically,and Mach number of 0 ~ 4 and change laws of base drag in both conditions with or without jet are acquired. The results show that the effect degree of base drag causing by booster jet is changing with the changes of altitude and Mach number. Compared with the condition of without jet,the base pressure reduces and base drag raises because of the ejector action causing by booster jet in the conditions of low altitude and subsonic,under high altitude and supersonic conditions,base drag reduces because of environment pressure reduces and expansion angle raises leading to base pressure reduces. With the altitude increasing and environment pressure decreasing,the booster jet and extern flow produce an interference pattern and form shock waves,which lead to the increase of base pressure,even produce additive thrust.