Modelling spreading with degassing using anisotherm viscoplastic multiphase shallow water approximation

Thomas Schiano (1, 2) , Barbara Bigot (1, 2) , Jean-François Haquet (1, 2) , Pierre Saramito (3) , Claude Smutek (4, 5)

1 SMTA - Service Mesures et modélisation des Transferts et des Accidents graves
2 IRESNE - Institut de recherche sur les systèmes nucléaires pour la production d'énergie bas carbone (CEA - DES)
3 EDP - Equations aux Dérivées Partielles
4 LGSR - Laboratoire GéoSciences Réunion
5 IPGP (UMR_7154) - Institut de Physique du Globe de Paris

A tridimensional multiphase viscoplastic anisotherm free surface model is developed, it is reduced to an height-averaged bidimensional model and its use for molten nuclear core spreading is argued with dimensionless numbers. It describes the tridimensional flow as non-Newtonian, non-isothermal and a mixture of a continuous phase and gas released from a substrate. Using an adaptive finite element method based on C++ library Rheolef, simulations are ran. A sensitivity analysis on the numerical parameters and the gas inflow rate are conducted. Tridimensional solution of the problem is computed from the bidimensional height-averaged solution.

Mots clés: Spreading; Free-surface; Shallow Water; Degassing; Phase field; Modelling; Numerical Simulation

Domaines: Mécanique [physics]; Equations aux dérivées partielles [math.AP]

Thomas Schiano, Barbara Bigot, Jean-François Haquet, Pierre Saramito, Claude Smutek. Modelling spreading with degassing using anisotherm viscoplastic multiphase shallow water approximation. International Journal of Multiphase Flow, 2023, 167, pp.104527. ⟨10.1016/j.ijmultiphaseflow.2023.104527⟩. ⟨hal-03893508⟩