Abstract: This rocket motor propellant grain is designed to reduce recession of at least the converging portion of a converging/diverging rocket motor nozzle. The propellant grain has an oxidizer-deficient grain portion constructed and arranged in relation to the nozzle to create, upon ignition of the propellant, a boundary layer of oxygen-deficient combustion products that flows through the nozzle throat passage and over an internal surface region of the nozzle. The boundary layer functions to at least substantially isolate the internal surface region of the nozzle from oxidizers contained in the combustion products generated from portions of the propellant grain having higher concentrations of oxygen than the oxidizer-deficient grain portion. As a result, the oxygen-rich portions of the propellant are unable to react with and thereby cause recession of the nozzle internal surface.

Abstract: A booster stage is positioned down-bore from the breech of a gun to contain a charge of liquid propellant that is ignited by the combustion gases of a detonated breech propellant charge trailing the projectile down the gun bore. The detonated liquid propellant increases the bore gas pressure and thus accelerates the projectile to a higher muzzle velocity.

Abstract: This invention provides a gun having a combustion chamber (combustor) which is filled with a charge of monopropellant or bi-propellant to less than full volume, (e.g. 30 to 90%) prior to ignition thereof, which is ignited with a tangential flow of ignition gas from the side or rear to establish the desired pattern of combustion gas in the charge.

Abstract: This invention provides a gun having a combustion chamber (combustor) which is filled with a charge of monopropellant or bi-propellant to less than full volume. (e.g. 30 to 90%) prior to ignition thereof. which is ignited with a tangential flow of ignition gas from the side or rear to establish the desired pattern of combustion gas in the charge.