Experimental Analysis of Rib Influence on a Non-Newtonian Fluid Atomization

An experimental study has been performed for proving the role of an internal in nozzle of pressure atomizer in non-Newtonian fluids atomization. A rib in perpendicular to fluid flow direction has been added to a simple pressure atomizer. The atomization process was experimentally characterized using of aqueous Carbopol 940 solution (0.23wt%). The liquid jet generation and spray formation was observed by CCD high speed camera and interpreted with image processing software. The results show the rib causes the flow pattern to shift from non-atomizing solid jetto atomizing jet and to form spray. However, with changing the flow pattern into atomizing jet, the pressure drop increases and also mass flow ratedecreases. As the injection pressure increased, spray patterns embraces the jets breakup which can cause the small droplets to emerge due to the effect of the aerodynamic action, which, in turn, can result in smaller droplets size. The results show that the ribbed atomizer can be improved by designing and optimizing the shape, number and position of rib to reach best spray and hydrodynamics parameters. The most important achievement of this study is to propose a method to generate spray of non-atomizing non-Newtonian fluid jet at low injection pressures.

Keywords:

Atomization , Non-Newtonian Fluid , Pressure Atomizer , Experimental study