Modern gas-turbines employ fuel-air mixers that utilize jet-in-cross-flow(JICF)fuel-injection to achieve rapid fuel-air mixing.In recent years,air-assist JICF has been investigated to improve the atomization and fueldispersion qualities of JICF.This paper describes an experimental investigation of the effects of air-assist and momentum-ratio(J)upon the dynamics of JICF sprays at elevated pressures and temperatures.In the investigation,the liquid Jet-A was injected through a wall-recessed orifice,while four slots surrounding the base of the recess supplied air streams that impinged on the jet at 45o.Two arrangements of 10kHz high-speed Miescattering imaging were applied to capture the resulting spray plume:(1)simultaneous capture of the plumes integrated Mie-scattering from the top and side-views,and(2)capture of planar Mie-scattering across two different cross-sectional slices of the plume.The resulting images were post-processed using a newly developed Moments-algorithm that described each instantaneous spray plumes trajectory and dispersion in 3-dimensional space,as well as the fluctuation magnitudes of the plumes trajectories in time.The Moments-algorithm is also capable of digitally reconstructing and animating a sequence of instantaneous spray plumes in 3D,which serves as a useful visualization tool for engine designers and CFD validation.The investigation found that air-assist moderately enhanced spray penetrations,while significantly increasing the spray plumes lateral widths and fluctuations.