Rocket engine nozzle is a propelling nozzle used to expand and accelerate the combustion gases produced by burning propellants to supersonic exit velocities. To furnish high performance and thrust, a maximum of the energy which is released inside the combustion chamber due to the reaction of the propellant and the oxidizer has to be converted into kinetic energy. This converted energy emits high heat fluxes that damage the nozzle that is so expansive to realize. For this matter, lots of researches were established to invent multiple cooling techniques in a way to avoid the damage of the nozzle, so recovering it for to be operative again. This work aims to identify the quality of cooling using the method of film injection. A numerical simulation is run on a scale model of a BKE propulsive nozzle. A parietal injection is conducted in the divergent section where the heat fluxes are enormous what allows us to