Synthesis of Jet A1 gel fuel and its characterization for propulsion applications

In propulsion, structural stability on storage and fluidity during injection are the most required characteristics of gelled fuels, and it is vital to determine the effects of different parameters involved in gelling process on these characteristics. This study explores the effects of processing temperature and gellant concentration on the structural stability and sprayability of gelled Jet A1 fuel by means of static and dynamic stability tests and spray experiments. Results show that, gelled Jet A1 fuel processed at relatively low temperature exhibits more phase separation, rendering it unsuitable for storage, atomization, and combustion. Higher processing temperature imparts greater solidity and thus improves the structural stability with only marginal phase separation. Static stability tests revealed the minimum gellant concentration above which stable gels are formed. Under dynamic conditions, the stability of gels is found to be enhanced by increasing the gellant concentration. Low gellant concentration induces phase separation. Spray images reveal the existence of unatomized gel lumps at the core and relatively larger droplets at the downstream of the atomizer exit with gelled samples processed at relatively high temperatures.

► Gelled Jet A1 processed at high temperature structurally stable but poorly atomized.
► High processing temperature gives more stability due to increased gellant solubility.
► Stability increases with gellant conc. due to increased H-bonding at 60 and 63 °C.
► Better atomization, minimum separation at optimum temperature and gellant conc.