Method for film cooling of liquid-propellant rocket engine chamber and a device for its realization (versions)

RU patent № 2135809

The method is intended for use in systems for cooling walls of the engine chamber. The method is implemented in the following way: using the gasdynamic step, in the after-step space from the near-wall part of boundary layer a zone of free gas flows of relatively small velocities is formed, within the limits of which a thin continuous film of liquid coolant is formed and fed to chamber walls. The offered four versions of jet screen allow one to realize the above method in a liquid-propellant rocket engine featuring different parameters. All these jet screen zones comprise such main elements as an annular collector with inlet orifices which distribute and swirl the liquid coolant flow, the collector passing into an outlet slot, a gasdynamic step and a shaped wall of the space behind the step. Two versions feature a smooth slot of different width, two other versions have small inclined vanes in the outlet slot: closed vanes in one version and open ones in the other. The proposed method allows one to concentrate the liquid coolant, supplied to the jet screen zone, in the ultimately thin wall layer of gases that provides attainment of high efficiency of the gas jet screen in reducting the heat transfer from the gas flow, and minimum losses of engine specific impulse, including zero losses under certain conditions. Alternative versions of the device provide formation of a continuous thin film of liquid coolant on the chamber wall, which is necessary to attain a high efficiency of the film cooling and minimum losses of specific impulse, including zero losses under certain conditions.