Experimental investigation of spray characteristics in subsonic crossflows\ud

The breakup of a liquid jet, in a crossflow leading to the evolution of the spray plume downstream is an important aspect that needs to be well understood for improving combustion efficiency and reduction of emissions for airbreathing propulsion engines. The drop size characteristics of a liquid jet in a non swirling\ud crossflow of air were investigated experimentally at conditions relevant to ramjets and gas turbine\ud afterburners. Experiments were done with a 1.0 mm diameter plain orifice nozzle which was flush mounted on the bottom plate of test section to provide normal injection. Laser diffraction using Malvern Spraytec particle analyzer was used to measure drops size and distributions in the near field of the jet. The momentum flux ratio was varied to address a reasonable range of liquid flow rates as in practical devices. The sprays were characterized using the non dimensional parameters such as the Weber number and the\ud momentum flux ratio and drop sizes were measured at an\ud axial distance of 50 mm from the injector. Results\ud indicate that as one goes from the bottom to the top of\ud the spray plume, the drop size distribution becomes\ud narrower. Further with increase in the momentum flux\ud ratio the volume concentration across the plume becomes highly non uniform and depends on the measurement point in the expanding spray plume