Revisiting Modeling Techniques and Validation Experiments for Two-Phase Choked Flows Relevant to LOCA

摘要

This paper deals with the modeling of the 1D 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 Delayed Equilibrium Model (DEM) or the Homogeneous Relaxation Model (HRM) have been developed and tested in previous studies. These models were revisited and improved in view of their future implemention in the next CATHARE code generation during the EU NURISP (Nuclear Reactor Integrated Software Platform) project. Some new results of these models are compared against experimental data mainly obtained at CEA Grenoble (Super-Mobydick experiments), and additional benchmarks are proposed for further validations