Modelling heat transfer in two-fluid interfacial flows

This paper presents a method to calculate heat transfer across an interface separating immiscible fluids. A volume tracking method was used to model the simultaneous movement of mass, momentum and energy across cell boundaries. Both first- and second-order methods were used to approximate temperature fields with sharp gradients that exist near the fluid–fluid interface. Temperature distributions around hot droplets surrounded by a colder fluid with uniform velocity were calculated and the magnitude of false diffusion identified. The effect of changing the thermal diffusivity of the surrounding fluid was studied. It was found that in most cases a second-order approximation, such as the van Leer scheme, is sufficient for estimating advection temperatures. To demonstrate the capabilities of the model we modelled molten tin droplets falling in an oil bath. The development of vortices behind droplets was modelled and the effect of fluid re-circulation and oil thermal conductivity on heat dissipation studied