Characterization of fuel regression in a radial flow hybrid rocket

Reliable ignition and stable combustion have been achieved in a lab-scale radial-flow hybrid rocket engine. The device utilizes 85% hydrogen peroxide and polyethylene and was tested at chamber pressures ranging from 118 to 238 psia. Fuel regression behavior was characterized with respect to initial geometry and mass flux. The measured regression rates are greater than observed in axial port designs at the same flux and chamber pressure levels. Although the regression behavior is effected locally by the three-dimensional flow structure, the results were more uniform than predicted by lumped parameter ballistics approximations. For this reason, radial-flow designs with acceptable fuel utilization appear to be feasible.