Regression Rate End-Burning Hybrid Rocket Motor Doped with High Entropy Metallic Additives

Abstract

Hybrid Rocket Motor (HRM) has a critical weakness that impacts performance because of low regression rate. Due to this, extensive investigation has been done on the end-burning hybrid rocket (EBHR) to enhance the regression rate. Analytical studies were conducted on the EBHR to model the internal ballistic flow field in the combustion port at different initial configurations. The present investigation is focused on single port EBHR, paraffin wax doped with high entropy additives (HEA), and gas oxygen as the fuel and oxidiser, respectively. Three different HRM configurations will be investigated to compare the enhancement of regression rate: conventional HRM, EBHR, and EBHR with additives. The experimental work was conducted using FeCoNiAl(0.1-x)BxSi doped in paraffin wax for end-burning static firing. HEA contributes to an increase of 1.11% to the regression rate, 12.27% to the thrust, and 12.16% to the specific impulse of the HRM compared to pure paraffin wax fuel. EBHR has an overall lower performance than conventional HRM. The results show an increase of 44.32% and 52.75% in regression rate for fuel with 5% and 7% HEA concentrations, respectively, compared to the baseline of 3%. The mass of the fuel has the most impact on the regression rate, with an increase of 104.4% for 50% more fuel mass compared to the baseline. However, the HRM with the highest specific impulse is the one with a rise of 22.62% mass flux as compared to the baseline.