Assessment of stratification and entrainment models in CATHARE 3 code against TPTF-H and Mantilla experiments

Sofia Carnevali (1) , Philippe Fillion (1)

1 STMF - Service de Thermo-hydraulique et de Mécanique des Fluides

This paper presents the assessment of CATHARE 3 code against tests performed in the horizontal TPTF (Two Phase Tests Facility) and Mantilla facilities. This activity falls within the framework of a benchmark conducted by the Forum & Network of System Thermal-Hydraulics Codes in Nuclear Reactor Thermal-Hydraulics (FONESYS). The aim of this benchmark is to highlight the capabilities of SYS-TH codes to predict the horizontal stratification criteria and the onset of droplet entrainment and entrainment rate. One of the objectives of TPTF experiments, conducted by JAERI (Japan), was to analyse the thermalhydraulic responses in the horizontal legs of LWR. The considered tests were at steady state and saturated steam/water two-phase flow conditions for a pressure varying between 3 MPa and 12 MPa. CATHARE code simulations show a general rather good agreement with TPTF-H experimental results although some improvements like the stratification regime prediction seem necessary. In two horizontal test sections with different diameters, Mantilla carried out air/water experiments at low pressure, from stratified to annular flow conditions, including droplet entrainment. Entrainment fraction obtained both with the two-fluid 6equation model and the 3-field model of CATHARE are compared against the experimental data. Some improvements of the existing models are proposed for the entrainment and deposition processes to better fit the experiment.

Mots clés: Horizontal flow; Stratified flow; Droplet entrainment; CATHARE

Domaines: Mécanique des fluides [physics.class-ph]

Sofia Carnevali, Philippe Fillion. Assessment of stratification and entrainment models in CATHARE 3 code against TPTF-H and Mantilla experiments. NURETH-19 - The 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Mar 2022, Bruxelles (Conference virtuelle), Belgium. ⟨cea-03985842⟩