Numerical study of the flow and heat transfer in a turbulent bubbly jet impingement

This contribution presents the results of modeling of the flow structure and heat transfer enhancement obtained by adding air bubbles into a turbulent liquid (water) impinging jet. A set of axisymmetrical steady-state RANS equations for the two-phase flow is utilized. The dispersed phase (bubbles) is modeled by the Eulerian approach. Liquid-phase turbulence is computed with the Reynolds stress model, taking into account the effect of bubbles on the carrier phase. The effect of changes in the gas volumetric flow rate ratio and bubble size on the flow structure, wall friction, and heat transfer in a gas liquid impinging jet is numerically studied. The predictions demonstrate the significant anisotropy of the turbulent fluctuations in the axial and radial directions for the bubbly impinging jet. The addition of a gas phase into the turbulent liquid increases the wall friction (by up to 40% in comparison with the single-phase liquid jet) and heat transfer (by up to 50%). (C) 2015 Elsevier Ltd. All rights reserved.