Numerical Investigation of the Flow Pattern and the Heat Transfer in Divergent Vortex Tubes for Cyclone Cooling Applications

Abstract This paper investigates the flow field and the heat transfer in divergent vortex tubes for cyclone cooling applications. Previous studies have focused on configurations with constant or convergent geometries, while the effects of geometric divergence on cyclonic flow structures have received little attention. In the present work, diverging cyclonic flows are analyzed using Delayed Detached Eddy Simulations (DDES) in combination with the Spalart–Allmaras turbulence model implemented in OpenFOAM and are compared to reference cases of constant cross-section cyclone cooling. The simulations reveal distinct modifications of the flow structure and the heat transfer induced by the geometric divergence. Grid independence of the numerical results is demonstrated to ensure numerical robustness. Experimental particle image velocimetry (PIV) measurements are conducted for validation, and key flow quantities are quantitatively compared with the numerical predictions.