Direct contact heat transfer between immiscible fluid layers in laminar flow

The problem of heat transfer (and, by analogy, mass transfer) between immiscible fluids in laminar parallel flow is analyzed as a conjugated boundary value problem. Exact solutions are developed in terms of known functions by solving for the temperature fields in the two phases separately for constant boundary conditions, then generalizing the results to obtain solutions for the interfacial temperature distribution and the complete temperature field for the conjugated system. The analysis and the results of calculations for heat transfer between two immiscible films flowing down an adiabatic inclined plane are presented. It is shown that axial conduction can be included, and the effects of axial conduction in one stream are examined. The predicted Nusselt numbers are plotted versus axial position for various parameters, and the interfacial temperatures and mixed mean fluid temperatures for the two phases are plotted to elucidate the heat transfer characteristics.