La modélisation numérique fine appliquée à l'analyse thermohydraulique

Refined numerical modelling in thermal-hydraulic analysis

¹ Electricité de France, Direction des Etudes et Recherches, Laboratoire National d' Hydraulique, 6 Quai Watier, 78400 Chatou, France
² Commissariat à l'Energie Atomique, Direction des Réacteurs Nucléaires, Département de Thermohydraulique et de Physique, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
³ Commissariat à l'Energie Atomique, Direction des Réacteurs Nucléaires, Département de Mécanique et de Technologie, 91191 Gif-sur-Yvette Cedex, France

Abstract

The paper presents the strategy for the development of numerical models and software in EDF and CEA, for the computation of nuclear reactor single-phase thermal-hydraulics problems. These tools use the Navier-Stokes equations coupled with the k-ε model for turbulence, and have been validated upon simple situations of isothermal and non-isothermal flows, including recirculating flows, and stratified flows appearing under transient situations in closed cavities or in pipes. Further developments of these tools are undertaken in order to reach better accuracy in the treatment of some particularly complex turbulent flow situations, and in order to get informations on the temperature fluctuations. ln that scope, use was made of transport equations for Reynolds stresses, turbulent heat fluxes, and/or for the dissipation rate of temperature fluctuations. Results with these second moment closures are shown on stratified channel flow, heated boudary layers and jets.