Evaluation of Boron Combustion for Ducted Rocket Applications Using Condensed Product Analysis

Syed Alay Hashim; Srinibas Karmakar; Arnab Roy; Muazu Abubakar

doi:10.14429/dsj.74.18685

Syed Alay Hashim Department of Aerospace Engineering, Alliance University Bangalore, Karnataka, 562106, India https://orcid.org/0000-0001-8678-9994
Srinibas Karmakar Department of Aerospace Engineering, Indian Institute of Technology Kharagpur, West Bengal, 721302, India https://orcid.org/0000-0002-2622-4892
Arnab Roy Department of Aerospace Engineering, Indian Institute of Technology Kharagpur, West Bengal, 721302, India https://orcid.org/0000-0002-9481-9871
Muazu Abubakar Department of Mechanical Engineering, Bayero University Kano, PMB 3311, Nigeria https://orcid.org/0000-0001-5889-0454

DOI: https://doi.org/10.14429/dsj.74.18685

Keywords: Boron-based solid fuel, Additive loading, Thermal analysis, Residual products, Ducted rocket

Abstract

Boron, a metalloid, produces high energy upon combustion. It is recommended as an ingredient for fuel or propellant in rocket propulsion, despite the challenge of extracting its full thermal energy. So far no one has claimed the complete energy conversion of boron upon combustion. On the other hand, the current propulsion system of the Meteor missile uses boron-loaded propellant. The boron-loaded propellant provides an approximately three-fold increase in specific impulse compared to conventional propellants. The present study focuses on boron-HTPB-based solid fuels impregnated with early ignited particles as additives, aiming to assess the combustion performance of boron particles. These additives are magnesium (Mg), titanium (Ti), and activated charcoal (C), and their effects are evaluated based on the residual active boron content in the condensed combustion products (burned residues). An economical tool commonly called stagnation flow or opposed flow burner (OFB) is used to deflagrate the fuel sample by means of pressurized oxygen gas. The condensed combustion products are examined using a field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). Among the fuel combinations investigated here, magnesium has been found to be a good burning enhancer of boron, leaving the lowest active boron content (30%) in the burned-out residue. The current research aims to develop an efficient boron-containing solid fuel for hybrid propellant ducted rocket engine applications.