Three dimensional modeling of boiling flow for the NEPTUNE code

This paper deals with the 3D modelling of two-phase boiling bubbly flow in a vertical duct. More attention is paid to the modelling of the Interfacial Area Concentration which is of fundamental importance in the numerical prediction of boiling bubbly flow. A balance equation is derived for this quantity, including several terms for modelling the bubble coalescence and break-up and the bubble size and number variations due to phase change. The complete model is tested against the DEBORA experimental data base, and the IAC model is compared to three other models found in the literature. The results of the numerical simulations are compared to the experiment and discussed. Quite good agreement is found on the bubble diameter profiles by using our model. This work is part of the NEPTUNE project