MITIGATION OF SLIVERS USING A NEW PROPELLANT GRAIN DESIGN TO IMPROVE PROPULSION SYSTEMS

Abstract

The research work addresses mathematical modelling and computational analysis of novel solid propellant grain configuration. The aviation industry is working on propulsion systems as well. For high thrust in rockets, space ships, and even in aircraft, solid propellant grains can be used as fuel. Grain design is a vital and integral part of solid propellant design. The designer has many options available for selecting grain configuration. Several design parameters – volumetric loading fractions, web fraction, length to diameter ratio, and port area – are normally tailored to mission demands. The star grain configuration has been a mainstay in this industry since 1935. The star grain configuration does however have a long-standing drawback, namely the formation of slivers. In this paper we present a new grain configuration, the “rose petal”, which overcomes the drawback of the traditional star grain design. The configuration is modelled using relevant internal ballistic relations. The design computation is executed in MATLAB. Thrust and time and burn area time curves are generated for a prescribed port area. Comparisons are drawn between the two configurations, clearly revealing that the new configuration obviates the occurrence of unwanted slivers otherwise generated in the old star design, which lowers the efficiency of all those propulsion systems in which solid propellants are used.