Accession Number : AD0276486

Title :   INVESTIGATION OF METHODS OF OBTAINING SUBSTANTIAL IMPROVEMENT OF LIGHT GAS HYPERVELOCITY LAUNCHER PERFORMANCE

Corporate Author : ENGINEERING-PHYSICS CO ROCKVILLE MD

Personal Author(s) : CUSHING,BOWDEN,GEORGE E.

Report Date : 15 JUN 1962

Pagination or Media Count : 1

Abstract : An analytic study of light-gas hypervelocity projectors has been made to determine ways of increasing the pellet velocity. A simple mathematical model of a light-gas projector in which the gas expansion is assumed isentropic is compared with two similar models; one in which the expansion is isothermal, and the other in which the pressure at the base of the pellet is held constant. A sensitivity analysis of all three models is described. The energy which must be injected into the light gas to achieve isothermal expansion and/or constant base pressure is computed. Two methods of injecting energy are described and critically examined. It is concluded that, although some improvement in performance may be achieved with isentropic expansion by pre-heating the gas, increasing the structural pressure limit of the projector, and increasing the expansion ratio; i.e., the barrel length, the extent of this improvement will be limited. Greater improvement can be attained through energy augmentation. It is recommended that a more detailed analytic study of the effects of electrical and electromagnetic augmentation be undertaken coupled with an experimental investigation of methods of implementing augmentation. (Author)

Descriptors :   *HYPERSONIC TEST VEHICLES, *HYPERVELOCITY GUNS, *HYPERVELOCITY PROJECTILES, EQUATIONS OF STATE, GAS FLOW, HELIUM, HYDROGEN, PARTIAL DIFFERENTIAL EQUATIONS, PELLETS, PRESSURE

Distribution Statement : APPROVED FOR PUBLIC RELEASE