Hypergolicity and ignition delay study of pure and energized ethanol gel fuel with hydrogen peroxide

Abstract

An experimental study of hypergolicity and ignition delay of pure and energized gelled ethanol with hydrogen peroxide was carried out. Experimental drop test results were obtained and discussed by using Photron high speed camera imaging. This study represented a sufficient repeatability of ignition delay for hypergolic gel bipropellant development. Gelled ethanol fuel (pure and energized with nano-Al/B/C particle substitution) mixture with metal catalysts were formulated to examine its hypergolicity with ignition delays on the order of 1-30 ms in most of cases, which are comparable with the existing liquid hypergolic bipropellant systems. The minimum ignition delay time was recorded for boron case at 1.33 ms. And the calculated activation energy for the gelled ethanol fuel with pure and energetic particle substitution system resided within the range of 7-13 kJ/mole along with shear thinning behavior. Temperature profile also indicated an exothermic nature of the propellant system with 1000 to 1600 K recorded. Parameters such as apparent viscosity of the fuel, drop height and drop volume also played an important role for the hypergolicity of the system in a drop experimentation. It was also observed that the formation of a cage encapsulating the high temperature gases in a network formed by the gelling agent could result in a longer ignition delay. (C) 2016 The Combustion Institute. Published by Elsevier Inc. All rights reserved.