Evaluation of Radiative Heat-Transfer Effect on Paraffin-Wax Regression Rate in Hybrid Rocket

Abstract

A numerical setup has been developed to rebuild the axial profile and time history of the regression rate of a paraffin-wax-based fuel in a hybrid rocket, with the main target of investigating the effect of the local radiative heat transfer from both the combustion gas molecules and soot particles. The numerical approach is based on a quasi-one-dimensional computational fluid dynamic strategy, which is coupled with chemical equilibrium combustion; the vaporization and entrainment components of the wax-fuel regression rate have been estimated with an established liquefying-fuel model. The increase of the convective heat-transfer blocking due to radiation and the effect of recirculation flow due to oxidizer injection have been introduced. Numerical results are compared with experimental data. When radiative heat transfer, blocking-effect correction, and recirculation flow effect are taken into account, the calculated and measured fuel regression rates agree well in both values and axial profiles.