GB972724A - Rocket motor - Google Patents

Abstract

972,724. Semi-solid propellent charges; rocket motors. ATLANTIC RESEARCH CORPORATION. April 9, 1962 [May 19, 1961], No. 13519/62. Heading F3A. A rocket motor comprises a casing containing semi-solid monopropellant which forms a viscous pool and has a single exposed upper surface or burning surface when the motor is in an upright position, the gases of combustion being vented out of said casing through a downwardly-directed nozzle which communicates directly with the space above the upper surface and wherein this surface regenerates downwardly during burning in a direction opposite to the direction of thrust. The embodiment of Fig. 3 has rearwardly-directed nozzles 30 at the forward end of a casing 31, each component being lined with insulating material 37, and a spider 39 from which are suspended metal rods or tubes 38 of circular or polygonal crosssection. Burning of the propellant occurs only at its forward face after this has been ignited by a conventional electric igniter and the rods or tubes increase the rate of burning by increasing the available burning area. Conduction of heat by the metal causes the formation of recessed burning areas of conical shape with the rods or tubes passing through their apices. Suitable metals mentioned include copper, silver, aluminium, platinum, palladium, tungsten, magnesium, chromium and steel, the maximum metal thickness being about 0.05 inch. To further increase the burning rate, the metal conductors may be coated with a solid propellant of higher linear burning rate than the monopropellant and to obtain a burning rate intermediate that of the monopropellant with and without bare metal conductors, they may be coated with solid propellant of lower linear burning rate than the monopropellant or with an inert solid insulator such as cellulose acetate, polyvinyl chloride, silicone or an enamel frit. Figs. 5, 6 show a motor of an annular plug nozzle construction wherein a contoured casing 51, made of material such as silica loaded phenolic resin, forms the plug. In this embodiment the rods are replaced by a metal honeycomb structure 55. Instead of rods, tubes or a honeycomb, short lengths of wire or foil, preferably, however, not less than 0.08 inch in length, may be randomly admixed with the semi-solid propellant before it is loaded into the motor. A motor is also described (Fig. 1, not shown) without reference to the presence of metal conductors, in which a nozzle is situated at the rear of the motor and is in communication with the space forward of the fuel by means of a centrally and longitudinaly disposed exhaust stack. Methods of loading the semi-solid monopropellant into the motor and compositions thereof are as described in Specification 972,723.