Hypergolic Studies of Ethanol Based Gelled Bi-Propellant System for Propulsion Application

Abstract

The experiments conducted in this study examined the hypergolicity and ignition delay of the formulated ethanol gelled fuel and hydrogen peroxide oxidizer bipropellant system. The hypergolicity and ignition delay data for bipropellant system are very important for propulsion applications. It was observed that the ethanol based gelled fuel systems were hypergolic with hydrogen peroxide (90% pure) in a presence of a suitable catalyst. The observed ignition delay was within the range of 10~50 ms, which was comparable with the existing liquid hypergolic bipropellant systems. Temperature profile also indicated that the hypergolic system attained a very high temperature profile range of 1000 8C to 1400 8C for a very small weight percent of fuel. Experiments conducted with two separate volumes of oxidizer, 14 ml and 50 ml. In both cases the propellant system was fuel rich. It was also observed that the formation of cage in the gel network, which could encapsulate the higher temperature gases and flame in a network, might be a plausible reason for recorded higher ignition delay.

Effect of Alcohol Carbon Chain on Enthalpy of Combustion and Ignition Delay Time for Gelled Hypergolic Propellant System

“…Propellant is formulated from alcohol family by varying carbon chain length from ethanol to heptanol, stabilized with cellulose based gelling agent. In past [18,19], weight percent of the gelling agent was reduced up to 6 wt.%, in present studies this weight percent was further reduced. The weight percent (wt.%) of gelling agent for gelation with respect to the formulated gel propellant are discussed in the previous publications [6][7][8][17][18][19], this is done to dominate the parent propellant properties and to reduce the effect of gelling agent as much as possible, for better performance.…”

“…The metal salts used are Manganese (II) acetylacetonate (C 10 H 14 MnO 4 , Sigma Aldrich) and Copper (II) chloride (Cucl 2 , Sigma Aldrich) which will be represented as MCAT and CCAT, respectively. The experimental setup (Figure 1) and methodology to calculate the ignition delays are similar to those discussed in reference [17][18][19]. Measured volume of oxidizer is introduced using Eppendorf dropper onto the propellant, catalyst mixture, with the high speed camera the events are recorded and the time is calculated from, when the propellant and oxidizer comes in contact to, first visible spark or flame, this provides us with the ignition delays.…”

“…Secondly, The gel system have the benefits of both liquid and solid propellant [4][5][6][7][8][9][10][11]. Hypergolicity of such bipropellant system with hydrogen peroxide can be achieved through suitable catalyst as a catalytically driven hypergolic bipropellant system [12][13][14][15][16][17][18][19][20][21]. The range of heat generated (~Heat) is from 54 kJ/mole to 400 kJ/mole based on the decomposition technique [1].…”

Preliminary Assessment of Hydrogen Peroxide Gel as an Oxidizer in a Catalyst Ignited Hybrid Thruster

“…Today, gelation technology attracts much interest [23][24][25][26][27][28][29][30][31] for its potential to increase enthalpy using metal particles as additives, deliver greater stability, and increase storability in respect of liquid propellants. The gel propellant has increasing viscosity at a decreased shear rate in a storage, which can contribute to the storability of hydrogen peroxide as well.…”

“…The gel propellant has increasing viscosity at a decreased shear rate in a storage, which can contribute to the storability of hydrogen peroxide as well. Several studies [23,24,26,[31][32][33][34] have reported the hydrogen peroxide gelation process, which has been mainly for better stability and storability of H 2 O 2 without any additives of metal powers, and possibility of use of the H 2 O 2 gel as a hypergolic propellant combination. However, little research has been reported in regards to gel propellant decomposition.…”