Zia Ur RahmanPunit Kumar Maharshi, SSPunit Kumar MaharshiSamuel, AASamuel2026-02-122026-02-1227-05-202573p.https://gnanaganga.alliance.edu.in/handle/123456789/9669The utilization of HTPB-based solid fuel formulations in rocket and missile propulsion systems has recently garnered significant attention. Boron, a metalloid with high theoretical energy potential, is commonly used as an active component in solid fuels, often with metal additives to enhance combustion performance. Boron-based HTPB fuels are well-suited for solid fuel ramjets (SFRJ) and ducted rockets (DR). This research aims to study the combustion performance enhancement of B-HTPB based solid fuels, with iron as metal additive in a laboratory-scale hybrid ducted rocket motor (HFDR) incorporating a regenerative mixing design. The expectation is that iron would play a role in enhancing the combustion performance of boron. In this study, the primary focus is on determining the regression rate and chamber pressure achieved in the secondary combustion chamber of the hybrid ducted rocket motor. The addition of iron to the base BHTPB fuel caused an 18.6% drop-in regression rate while increasing the secondary combustor pressure. Other key investigations such as the analysis of composition of condensed combustion products (CCP) and pre- and post-burn grain surface analysis are also carried out in the present study. To determine the percentage residual active boron content, condensed combustion products (burned products) are collected and evaluated using thermogravimetric (TG) equipment. Consequently, the characterization analysis will provide a clear picture of the residual boron present in the burnt product. These experiments provide data on the overall performance of our innovative static hybrid fuel-ducted rocket design, which may be used in missile applications.enHybrid ducted rocketRegression rateCombustion efficiencyRegenerative mixingOther