Simulation of the turbulent structure of a flow and heat transfer in an ascending polydisperse bubble flow

We report on the results of numerical simulation of the turbulent structure of a flow in a vertical polydisperse gas-liquid stream in a tube. The mathematical model is based on the application of the Euler description taking into account the inverse effect of bubbles on the averaged characteristics and turbulence of the carrying phase. Turbulent characteristics of the liquid are calculated using the model of transfer of Reynolds stress tensor components. The variation of the number of bubbles is described using the model of average volume of a bubble taking into account their splitting, coalescence, and expansion upon a change in the gas temperature. The effect of the change in the volumetric consumption gas content, the initial temperature of the liquid, and its velocity on the structure of the flow and on the heat transfer in the two-phase flow is analyzed. The addition of the gas phase to the turbulent liquid causes an increase in the heat transfer by more than 2.5 times. Comparison of the results of simulation with experimental data shows that the approached developed here makes it possible to simulate bubble turbulent flows with heat exchange with the tube wall in a wide range of gas contents.