THERMAL SCIENCE

International Scientific Journal

Milan M Popović

,

Milivoje M Popović

,

Predrag M Elek

A NOVEL GRAIN CONFIGURATION FOR DUAL THRUST SOLID ROCKET MOTOR USING TWO PROPELLANTS

ABSTRACT
This paper presents the design of a propellant grain for a dual-thrust solid rocket motor, combining slotted and end-burner grain geometries with two propellants of different burn rates. This novel approach achieves a high thrust ratio between the two-phases while ensuring nearly neutral burning throughout motor operation. Key performance parameters, such as chamber pressure and thrust, can be predicted analytically, with experimental tests demonstrating excellent agreement with theoretical models. The proposed design offers several advantages: neutral burning in both phases, a highly flexible and high thrust ratio, rapid pressure reduction during phase transition, minimal sliver formation, and quick motor extinction at the end of the second phase. Additionally, the use of thermoplastic propellant technology allows for the integration of multiple propellants within a single grain, providing versatility in using cylindrical-shaped grains for various applications.
KEYWORDS
Solid Rocket Motor, dual thrust, propellant grain design, grain burnback analysis, thermoplastic composite propellant, rocket motor performance parameters, static rocket motor test
PAPER SUBMITTED: 2024-12-30
PAPER REVISED: 2025-03-25
PAPER ACCEPTED: 2025-04-14
PUBLISHED ONLINE: 2025-05-10
DOI REFERENCE: https://doi.org/10.2298/TSCI241230087P
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2025, VOLUME 29, ISSUE No. 6, PAGES [4693 - 4701]
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A novel grain configuration for dual thrust solid rocket motor using two propellants

© 2026 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence