Catalytic Ignition Delay Investigation of Hybrid Rocket Motor Based on 90% Hydrogen Peroxide and Polyethylene

This paper is aimed to analyze the effect of hybrid rocket motor catalyst bed efficiency on ignition delay through lab-scale firing tests and two-dimensional axisymmetric transient simulations. Catalytic ignition firing tests of hybrid rocket motor(HRM) with 90% hydrogen peroxide(90HP) and polyethylene(PE) propellant are studied. The equivalent catalytic temperature of 90HP is calculated during the monopropellant pressure buildup stage. In firing tests, the equivalent catalytic temperatures of 90HP are between 726K~941K. The ratio of the equivalent catalytic temperature to the theoretical catalytic temperature is similar to the efficiency of the consumed catalytic bed. The equivalent catalytic temperature of HP and the oxidizer mass flow rate will affect the ignition delay time. Corresponding simulation research has also been carried out. When the equivalent catalytic temperature of 90HP is 600K and 700K, the HRM cannot complete ignition. When the oxidizer flow rate is more than 200g/s, increasing the equivalent catalytic temperature of 90HP has a greater impact on the reduction of fuel grain heating time compared with increasing the oxidizer flow rate. Double exponential fitting is performed on fuel grain heating time, oxidizer flow rate and equivalent catalytic temperature of 90HP. The denominators of mox and THP in double exponential fitting differ by an order of magnitude.