Metal powder ignition characteristics in a hybrid rocket engine chamber

Earlier studies revealed that addition of metal powder to microcrystalline-wax improves the regression rate of hybrid rocket solid fuel, but ignition of the metal powder was not confirmed to have occurred in the hybrid rocket engine chamber. To confirm the ignition of metal powder in the hybrid rocket engine chamber, theoretical calculations and combustion experiments were conducted. Theoretical calculations were heat transfer calculations from the combustion flame of microcrystalline-wax to metal powder. Combustion experiments were conducted in our laboratory using a hybrid rocket engine and 2D visualization engine. Theoretical calculations suggest that the metal powder ignited in the chamber. However, adding the aluminum powder did not improve the regression rate. Adding magnesium powder partially improved the regression rate. Both metal powders improved the characteristic velocity. According to the 2D visualization experiments, both metal powders ignited in the chamber. Results of these experiments suggest that metal powder raises the combustion flame temperature in the hybrid rocket engine chamber and that the addition of metal powder improves the solid fuel performance.