Abonnement à la biblothèque: Guest
Page d'accueil ICHMT DL Année en cours Archives Comité de direction Centre international pour le transfert de chaleur et de masse

SIMULATIONS OF TWO-PHASE FLOWS WITH A MULTIFIELD APPROACH

DOI: 10.1615/ICHMT.2015.IntSympAdvComputHeatTransf.70
pages 78-96

Solène Fleau
Electricite de France, R&D Division, Chatou, France; Laboratoire de Modélisations et Simulations Multi-Echelle, Université Paris-Est Marne-la-Vallée, France.

Stephane Mimouni
Electricite de France, R&D Division, MFEE, 6 Quai Watier, 78400 Chatou, France

Nicolas Merigoux
Electricité de France, R&D Division, Chatou, France

Stephane Vincent
Laboratoire de Modélisations et Simulations Multi-Echelle, Université Paris-Est Marne-la-Vallée, France.

Résumé

Safety issues in nuclear power plant involve complex bubbly flows. To predict the behavior of these flows, the two-fluid approach is often used. Nevertheless, this model induces a numerical diffusion of interfaces, which results in a poor accuracy in the calculation of the local parameters. Therefore, to simulate large interfaces such as slugs or free surfaces, located methods have been developed using the single-fluid model. In this paper, the two approaches have been coupled in the CMFD code NEPTUNE_CFD to simulate adiabatic separated flows. The averaged momentum balance equations are solved for each field and are followed by an artificial compression step, which fixes the interface thickness and ensures mass conservation. Moreover, since the two-fluid model allows the existence of relative velocities at the interface, a drag force is used to cancel them. This article proposes also a new formulation for this force, to take into account the physical properties of the flow. To validate this approach, an analytical test case with a static bubble has been simulated with a mesh refinement test. Then, the simulation of the Kelvin-Helmholtz instability has been performed to highlight the effect of the modification of the drag force. The sheared interface is particularly sensible to this force, which has an important influence on the flow parameters such as the interface velocity. Finally, these developments have been compared to three other codes by simulating the Rayleigh- Taylor instability.

ICHMT Digital Library

Bow shocks on a jet-like solid body shape. Thermal Sciences 2004, 2004. Pulsed, supersonic fuel jets - their characteristics and potential for improved diesel engine injection. PULSED, SUPERSONIC FUEL JETS - THEIR CHARACTERISTICS AND POTENTIAL FOR IMPROVED DIESEL ENGINE INJECTION
View of engine compartment components (left). Plots of temperature distributions in centreplane, forward of engine (right). CHT-04 - Advances in Computational Heat Transfer III, 2004. Devel... DEVELOPMENT AND CURRENT STATUS OF INDUSTRIAL THERMOFLUIDS CFD ANALYSIS
Pratt & Whitney's F-135 Joint Strike Fighter Engine under test in Florida is a 3600F class jet engine. TURBINE-09, 2009. Turbine airfoil leading edge stagnation aerodynamics and heat transfe... TURBINE AIRFOIL LEADING EDGE STAGNATION AERODYNAMICS AND HEAT TRANSFER - A REVIEW
Refractive index reconstructed field. (a) Second iteration. (b) Fourth iteration. Radiative Transfer - VI, 2010. Theoretical development for refractive index reconstruction from a radiative ... THEORETICAL DEVELOPMENT FOR REFRACTIVE INDEX RECONSTRUCTION FROM A RADIATIVE TRANSFER EQUATION-BASED ALGORITHM
Two inclusion test, four collimated sources. Radiative Transfer - VI, 2010. New developments in frequency domain optical tomography. Part II. Application with a L-BFGS associated to an inexa... NEW DEVELOPMENTS IN FREQUENCY DOMAIN OPTICAL TOMOGRAPHY. PART II. APPLICATION WITH A L-BFGS ASSOCIATED TO AN INEXACT LINE SEARCH