Gaseous-film cooling of a rocket motor with injection near the throat

SUMMARY OF RESULTS An experimental investigation of gaseous-film cooling of the nozzle of a small JP-4 - gaseous-oxygen rocket motor was conducted using tangentially injected nitrogen as the coolant. 1. Gaseous-film cooling of a rocket nozzle can be accomplished with coolant injec- tion into the subsonic accelerating flow field with cooling lasting along the full length of the throat and divergent portions of the nozzle. tion slot was correlated to a significant distance beyond the nozzle throat by the Hatch- Papell relation, with hgL (heat-transfer coefficient times engine circumference) used as an integrated average from the coolant injection station to the separate data stations. In addition, both a change in the constant K from 0,04 to 0 and the use of local hot-gas static temperature as the driving T correlation of the present data. The following results were obtained: 2. The adiabatic wall temperature distribution downstream of the film-coolant injec- were required to achieve apparent