GB1474546A - Solid propellant fuel charge - Google Patents

Abstract

1474546 Rocket motors SOC NATIONALE DES POUDRES ET EXPLOSIFS 18 June 1974 [19 June 1973] 26957/74 Heading F3A A solid fuel charge for a socket engine, comprises a first fast-burning propellant selected to have a combustion rate greater than 15 mm./ sec. at 52‹ C., and a second, slow-burning propellant selected to have a combustion rate greater than 3 mm./sec. at - 31‹ C., said first and second propellants being arranged for initial simultaneous combustion over their entire surface areas to produce gases at a relatively high pressure, the slow burning propellant being so provided as to have a longer combustion period than the fast burning propellant whereby to provide gases at relatively low pressure after consumption of the first propellant, the ratio of the high and low pressures exceeding 1À4, the combustion characteristic of the slow burning propellant being such as to provide stable combustion thereof throughout a first range of restriction coefficients (defined as the ratio of the surface area of the charge undergoing combustion to the area of the exhaust opening from the combustion chamber) which exceeds and includes a second range of restriction coefficients within which the combustion characteristic of the fast burning propellant provides stable combustion. The charge may include a third propellant for simultaneous ignition with the fast and slow burning propellants, having a combustion rate and a combustion period intermediate those of the fast and slow burning propellants. The third propellant increases the ratio of the high and low pressures to 1À8. The combustion characteristic of the second propellant exhibits a plateau effect within the second range of restriction coefficients. Each of the propellants comprises a plurality of laminar elements of substantially equal thickness, the thickness of the elements of one of said propellants being different from the thicknesses of the elements of the or each other said propellants.