Theoretical and Experimental Heat of Combustion Analysis of Paraffin-Based Fuels as Preburn Characterization for Hybrid Rocket

Abstract

The energy characteristics and theoretical performance of the hybrid rocket fuels are discussed in this paper. Aluminum (Al) and boron (B) metal additives were used to increase the energy density of the paraffin-based solid fuels. To predict the energy characteristics, the heat of combustion was evaluated by adiabatic bomb calorimetry. Theoretical performance parameters such as specific impulse (Isp), flame temperature, and characteristic velocity were obtained with NASA Chemical Equilibrium with Applications (CEA) code. Calorimetric test results revealed that paraffin/polyethylene/boron (P/PE/B)-based fuel formulations exhibited the highest heat of combustion among all the tested fuels. The heat of combustion value of the P/PE/B sample at 25 wt% B loading was found to be 9612 ±16 cal/g and 9293±17 cal/g for the P/PE/Al fuel formulation. The CEA results showed that the addition of Al to paraffin is noneffective in improving specific impulse performance. When B loading increased from 5 to 25 wt% in the P/PE/B, the Isp increased by 47 s compared to pure paraffin. A specific impulse increase implies the possible propellant mass saving. The reduction of the oxidizer and fuel masses may yield increased payload performance for given boundary conditions. The P/PE/B25 formulation has reported the highest value of characteristics velocity (C*) compared to other paraffin-based formulation.

Characterization of Potassium Nitrate/Dextrose Solid Rocket Propellant Using Calorimetry

“…Two techniques were used to measure calorimetry in the samples, one is the Semi-Micro Calorimetry (SMC) to obtain the heat of combustion, and the second one is the Differential Scanning Calorimetry (DSC) to obtain the heat released and the decomposition temperature. The techniques were applied in the analysis of composite and hybrid propellants (22,23,26).…”

“…For the characterization of the propellant and to obtain the heating rates, the application of the calorimetric tests during the PRL-1 is necessary, and not only for the solid rocket, for aerospace propulsion systems, like was presented by Pal et al (22) for hybrid rocket, comparing the theoretical results of the mixture with the experimental data.…”

Comparative Study on Hybrid Rocket Fuels for Space Launch Vehicles Moving in Higher Orbits

“…This might be beneficial for specific application areas such as space mission, which demands less oxidizer tank volume for carrying more payloads. [7] Mariana Conti Tarifa and Loreto Pizzuti (2019) analysed the theoretical performance of hybrid rocket propellants. The specific impulse, characteristic velocity and adiabatic flame temperature over a range of O/F from 1 to 8.5, for a chamber pressure of 10 bar, have been obtained and analysed.…”

“…Adiabatic flame temperature: The adiabatic flame temperature in the combustion chamber depends on the oxidant choice. The higher the thermal energy obtained by the combination of the pair, the greater the amount of energy that will be transformed into kinetic energy, which will directly affect the performance parameters [7].…”

Thermal, Viscosimetric and Thermomechanical Combined Assessment of Mixture Modelled Composite Fuels for Hybrid Propulsion

“…Regarding both pure paraffins and thermoplastic polymers-paraffin composite fuels, literature has pointed out the performance relevance of fuel sample production assessment [10][11][12] and formulation selection based on physical properties [10,13,15]. Moreover, polyethylene-paraffin composite fuels have been shown to deliver both mechanical quality and combustion efficiency, while keeping appreciable gains in regression rates as compared to pure polymers [15][16][17].…”