Delayed equilibrium model and validation experiments for two-phase choked flows relevant to LOCA

Abstract

Abstract This paper deals with the 1-D Delayed Equilibrium Model (DEM) for choked or critical flow rate in steady state or quasi-steady state conditions and the selection of the relevant experimental data for assessing such models. In particular, the focus is made on thermodynamic non-equilibrium conditions, which prevail in the flashing process near the critical section. In this regard, relaxation models such as the DEM developed and tested in previous studies at UCL was revisited and improved in view of their implementation in the next CATHARE code generation during the EU NURISP (NUclear Reactor Integrated Software Platform) project. A methodology to implement the DEM into is developed. Some new results of the DEM are compared against experimental data such as Super Moby-Dick experiments done in CEA and the well-known Marviken experiments performed at quasi-real scale geometry of Nuclear Plant.