LAUSR

Abstract The results of a numerical investigation of the effect of droplets’ thermophysical properties on the flow structure, turbulence, and heat transfer in a two-phase mist flow in a sudden pipe expansion are presented. Predictions are carried out for droplets of water, ethanol, and acetone for initial droplet diameters varying in the range d1 = 1–100 μm. The RANS approach is used to simulate a gaseous phase, and the motion and heat transfer of a dispersed phase are computed using the two-fluid Eulerian model. Gas phase turbulence is predicted using the model of Reynolds stress transport modified for the case of particle presence. It is shown that the addition of droplets leads to a significant increase in heat transfer (up to 50% at ML1 = 0.05) in comparison with a single-phase separated flow. Heat transfer enhancement with the use of ethanol droplets is slightly higher than the corresponding value for water droplets (by approximately 10–20%). The length of the region of intensified heat transfer is maximal for water droplets, while it is minimal for acetone droplets. The effect of heat transfer intensification and suppression of carrier gas phase turbulence is minimal for the acetone droplets.