Directional control system for rocket motor uses injection of air through holes or slits in divergent bell of convergent-divergent nozzle

摘要

The nozzle is similar to that used in normal practice, with a throat (3) in which the gases leaving the combustion chamber (2) reach sonic speed. The throat is followed by a divergent bell (4) in which further expansion and acceleration takes place at supersonic speed. The additional feature consists of equispaced apertures (5) in the wall of the bell, for injection of high-pressure air or fluid. Injection of air through one of these apertures causes local separation of flow, with consequent deflection of the jet from the nozzle. The apertures may be positioned halfway between the throat and the rim or trailing edge (8) of the bell.