ID 208

Experimental study of Flow Blurring twin fluid atomization concept using transparent injector

 

Abstract:

Present study investigates the effect of geometric configuration of flow blurring atomizer on working principle of the atomizer using the transparent injector. The simple geometrical configuration that creates flow-blurring concept involves two initially concentric liquid and gas streams with orifice disc at exit where gas stream is forced into the liquid stream to create two-phase flow. Orifice diameter ‘d’, is same as the liquid tube diameter with gap ‘h’ between orifice disc and liquid tube end for side entry of gas stream into liquid jet prior to the orifice exit. The h/d ratio controls the flow focusing to flow blurring transition when it approaches 0.25. Such geometrical configuration leads to bifurcation of liquid and gas streams and recirculating bubble due to gas penetration in the liquid stream is observed. This penetration depth is found to affect the spray quality and transparent injector allows investigating into this particular aspect. The transparent injector with fuel tube diameter of 6 (mm) and provision for changing ‘h/d’ made up of cast acrylic was used for the experiments, and effect of different air to liquid ratio (ALR) by mass was studied using backlit visualization. The air and water are the two fluids for this study. The experimental results show that the increase in ALR ratio increases the air penetration in the fuel tube, simultaneously affecting the spray quality as finer droplets are observed at higher ALR.