Hypergolic Ignition of Kerosene-Based Gel Fuel with Hydrogen Peroxide in Rocket Motors

The present work seeks to characterize the hypergolic ignition of a proprietary propellant. It consists of hydrogen peroxide as oxidizer, a kerosene-based gel fuel and a certain amount of sodium borohydride as an energetic additive.
An experimental parametrical investigation was conducted in order to correlate between different physical and chemical parameters that affect ignition delay times. The aforementioned parameters are Weber and Reynolds numbers, momentum, kinetic energy and hydrogen peroxide concentration. The videos of the conducted drop-on-drop test were analyzed using digital image processing. The phenomenon of ignition and combustion of the gelled fuel was divided into two main events: the “Primary Ignition” and the “Fuel Ignition”. These delay times were calculated and plotted versus all different parameters and analyzed.
Increase in momentum and kinetic energy led to about 40% reduction in both primary and fuel ignition delay times. Usage of 90% hydrogen peroxide led to decrease of more than 20 ms compared to 70% hydrogen peroxide. Minimal ignition delay times of 4-5 ms were observed.