Dispersed flow film boiling

Dispersed flow consists of small liquid droplets entrained in a flowing vapor. This flow regime can occur in cryogenic equipment, in steam generators, and during nuclear reactor loss of coolant accidents. A theoretical analysis of dispersed flow film boiling has been performed using mass, momentum and energy conservation equations for both phases. A numerical solution scheme, including wall-to-drop, vapor to drop, and wall-to-vapor heat transfer mechanisms was used to predict wall temperatures for constant heat flux, vertical upflow conditions. Wall temperature predictions were compared to liquid nitrogen, Freon-12 and water data of four separate investigators with reasonable results. A local conditions solution was developed by simplifying the governing equations, using conclusions from the numerical model. A non-dimensional group was found which solely determined the non-equilibrium with the flow, and allowed hand calculation of wall temperatures. The local conditions solution was compared to data taken by five investigators with good results.Sponsored by National Science Foundation DSR Projec