FICTITIOUS DOMAIN SIMULATIONS FOR THE TWO-PHASE FLOW ENERGY BALANCE OF THE CLOTAIRE STEAM GENERATOR MOCK-UP

Michel Belliard (1) , Isabelle Ramière (2)

1 DER - Département Etude des Réacteurs
2 LCSE - Laboratoire de Chimie des Systèmes Extractants

The context of this paper is the numerical simulation of a nuclear component, in the framework of the NEPTUNE platform, by a fictitious domain method. We consider industrial simulations of twophase flows with the homogeneous equilibrium (or relaxed) model. The introduction of no remeshing fictitious domain method is mainly motivated by free surface studies, fluid-structure interactions or fast Cartesian mesh solvers. As a first step toward a full fictitious domain simulation, this paper focuses on the fictitious domain computation of the energy balance equation of a nuclear component. Considering the steam generator, this equation is solved by a finite-element volume-penalization method. We recall the model used for the energy balance equation and review the modelizations and the computations. An industrial simulation of the steam generator mock-up CLOTAIRE is presented in order to appreciate the accuracy and the limits of the fictitious domain approach. Exploring L2-norm error along some vertical enthalpy profiles, we claim that the relative error introduced by the fictitious domain method is globally decreasing with the space step and can be lower than 10-3 for space steps around the U-tube diameter size. We conclude that we can reach an enough precision for the industrial applications and benefit from numerical advantages due to the use of Cartesian meshes.

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

Michel Belliard, Isabelle Ramière. FICTITIOUS DOMAIN SIMULATIONS FOR THE TWO-PHASE FLOW ENERGY BALANCE OF THE CLOTAIRE STEAM GENERATOR MOCK-UP. The 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-12), 2007, Pittsburg, Pennsylvania, United States. paper 6. ⟨hal-00274329⟩