Hydrodynamic Studies of Bubble Absorber Withswirl Entry of Refrigerant

Experimental investigations have been carried out on a glass bubble absorber with swirl entry of air into absorber water column to understand the bubble hydrodynamic characteristics. The swirl motion to the air bubbles is imparted with the help of cavity type swirl generator. Numerical simulations of swirler with air have been performed to arrive at the swirl generator geometry. High speed photography technique is employed to visualize the bubble behaviour under the influence of swirl, experimentally. The present study considers still, co-current and countercurrent water flow directions with respect to air. Experiments are also conducted to study the effect of air and water flow rates on bubble characteristics such as departure diameter, departure time, rise velocity, etc. From visualization studies, the entire bubble evolution phenomenon can be divided into three stages: bubble initiation, growth, and detachment. It is observed that the direction of water flow has significant effect on bubble characteristics. Based on the experimental data, empirical correlations for non-dimensional departure bubble diameter have been proposed, which can be helpful to estimate the primitive bubble size in a bubble absorber