The modifications of near-wall turbulence structure and heat transfer by immiscible droplets in turbulent liquid–liquid two-phase flow

Direct numerical simulation based on finite difference schemes has been carried out for non-isothermal turbulent upward channel flow with four immiscible droplets whose density is higher than that of continuous-phase liquid. The interface was tracked by the modified volume-of-fluid method. The computational results show that both the outward flow in the wake and the wallward flow around the cap of droplets enhance heat transfer. These flows are attenuated by the adjacent droplet in the axial direction. The droplets deform large-scale streamwise vortices and attenuate small-scale streamwise vortices.