JP-10 Vapour Detonations at Elevated Pressures and Temperatures

There has recently been interest in employing hydrocarbon missile fuels in pulse detonation engines where fuel storability and safety are prime concerns [1-3]. These synthesized hydrocarbon liquid fuels such as JP-10 possess low vapour pressures and high carbon-tohydrogen ratios, and therefore have low detonability. In the vapour phase at 1 atm initial pressure, the detonation cell size of stoichiometric JP-10 in air is approximately 5 cm [3], which is more than three times that of hydrogen. However, under stagnation flow conditions at flight Mach numbers of interest, pressures can be increased several times, thus resulting in an increase in the detonability with a detonation cell size decreased towards that of hydrogen. This trend was indicated in some preliminary results of a previous paper [3]. The practical engine operation conditions lie between atmospheric pressure and the stagnation pressure at the maximum flight Mach number. Hence, it is necessary to know the detonation properties of the fuel over a wide range of initial pressures and temperatures. It is also necessary to obtain the detonation cell sizes at various mixture equivalence ratios in determining an optimal ratio of fuel to air.