Characterization of a Superheated Fuel Jet in a Crossflow

Abstract

An experiment was conducted to characterize a superheated fuel jet (Jet-A) injected into an unheated crossflow. The liquid phase of the fuel jet was characterized with high speed imaging and phase Doppler interferometry while the vapor phase of the fuel was measured with infrared scattering and extinction methods. The transition from a shear-atomized to flash-atomized spray at a fuel temperature of 465°F (513K) was observed at an ambient pressure of 1 atm, which is consistent with the bubble and dew point curves predicted for JP-8. The explosive breakup that was seen in the flash-atomized spray produced sub-micron droplets with a high radial and transverse momentum that resulted in an increasing fuel vapor concentration for the same penetration height when compared with the shear-atomized case. This unique behavior makes superheated fuels an attractive design feature for fuel preparation devices that can employ flash boiling to enhance fuel atomization and mixing in a compact volume.