Accession Number : AD0286076

Title :   PROPULSIVE SYSTEM SPECIFIC IMPULSE

Corporate Author : GENERAL DYNAMICS SAN DIEGO CALIF GENERAL ATOMIC DIV

Personal Author(s) : ROSS,F.W.

Report Date : 08 FEB 1960

Pagination or Media Count : 1

Abstract : The specific impulse of a propellant, I sub sp, is known to be ina equate by itself as a measure of the resulting effectiveness of a propellant system. With developments now extending toward newer types of propulsive systems, including liquid hydrogen and nuclear systems, the considerable differences in masses of propulsive equipments point up the need of an improved measure for such system effectiveness. A propulsive system specific impulse, I s b ss, is derived to fulfill this need. It includes the relative mass of equipment required by the propulsive system, as well as the I sub sp of the propellant. The resulting analytical expression for I sub ss brings out salient features of the propulsive system induced by dif erences in structural mass factors (other than payload masses). Specifically it shows: the nature of the minimum cutoff I sub sp, induced by the structural factor for each magnitude of mission velocity. If I sub sp is below this, the mission cann t be accomplished. For I sub sp increased above this cutoff value, I sub ss increases logarithmically to a theoretical limit determined again by the structural factor and mission velocity. (Author)

Descriptors :   MATHEMATICAL ANALYSIS, NUCLEAR PROPULSION, PROPULSION SYSTEMS, ROCKET PROPULSION, THEORY

Distribution Statement : APPROVED FOR PUBLIC RELEASE