Energy and Flow Separation in the Vortex Tube : A Numerical Investigation

As a localized cooling device the vortex tube is being used is several applications due to its simplicity, robustness and maintenance free service. Its design still depends on experiment based empirical relations and thumb rules. Capturing complete flow and energy separation features of vortex tube through experimentation is difficult due to the complexity associated to flow Numerical investigation of the vortex tube presented here intends to bring out unexplored features. The work is done on a 3D model of vortex tube with 6 nozzles and an adjustable cone valve. The parameters varied in the investigation are supply air pressure from 2 to 6 bars, the orifice diameter from 5 to 10 mm, L/D ratio from 4 to 20. The mechanism of flow and energy separation is completely explained based on present work. The impact of important performance parameters such as supply pressure, cold orifice diameter, tube diameter and its length suggest improvement in the present thumb rule for better vortex tube performance. Present work investigates the effect of working environment also where tube is assumed work under constant wall temperature and constant wall heat flux condition. It concludes that cooling performance of the tube is independent of thermal condition imposed on its wall.