Impact of zirconium nanoparticles on boron-paraffin wax-based hybrid propellant in ducted rocket applications

In the past few years, boron has gained a lot of attention as a solid fuel because of its high energy density, high combustion temperature, controlled burn rate, and reduced smoke and emissions. Boron is the second-most energetic metalloid in the periodic table. Nonetheless, it has been discovered that it is particularly reactive with oxygen, resulting in the formation of a boron oxide (B2O3) layer around the active boron, which radically altered the boron burning efficiency. In previous literature, several experiments have been carried out to improve the boron’s combustion performance, and it is recommended that the fuel carrying boron particles offers a lot of potential for ducted rocket (DR) engines. In the present study, a lab-scale hybrid-fuel ducted rocket (HFDR) is used to evaluate the combustion performance parameters (regression rate and combustion efficiency) of the solid fuel. Zirconium (Zr) nanoparticles are mixed with boron-based solid fuel to enhance the ignition and combustion properties of boron particles. A total of three distinct solid fuel samples—pure paraffin wax, paraffin wax loaded with boron particles, and paraffin wax loaded with boron and zirconium particles—are investigated experimentally. It is revealed that the introduction of Zr particles in boron-based solid fuel increased combustion efficiency by 33%.