NUMERICAL INERTIA AND DAMPING COEFFICIENTS DETERMINATION OF A TUBE-BUNDLE IN INCOMPRESSIBLE VISCOUS LAMINAR FLUID

Abstract

IN THIS PAPER, WE COMPARE THE PERFORMANCES OF TRANSPIRATION AND ALE METHODS. THE APPROACH ALE (ARBITRARY LAGRANGIAN EULERIAN) IS A POWERFUL TOOL TO TREAT COUPLED PROBLEMS, MORE PRECISELY, THE APPROACH ALE IN FINITE ELEMENTS OF DONEA AND HUGHES. HOWEVER, ALE PERFORMANCE FOR DETERMINING FLUID-ELASTIC FORCES AT SMALL VIBRATIONS AMPLITUDES IS STILL IGNORED. TRANSPIRATION METHOD IS A SIMPLIFIED APPROACH FOR CALCULATION OF FLUID-ELASTIC FORCES AT RELATIVELY SMALL VIBRATIONS AMPLITUDES. BASED ON A FIRST ORDER DEVELOPMENT OF VELOCITY BOUNDARY CONDITIONS, THIS METHOD ALLOWS THE USE OF A FLUID DOMAIN FIXED IN TIME DURING A DYNAMIC COMPUTATION, BY AVOIDING HENCE THE PROBLEMS DUE TO THE MESH DISTORTIONS. THE METHODS HAVE BEEN VALIDATED WITH HELP OF ANALYTICAL SOLUTION OF A VIBRATING CYLINDER IMMERSED IN STOKES CONFINED FLUID MEDIUM. WE MADE OTHERS ANALYSIS OF DYNAMICS CHARACTERISTICS IN TUBE-BUNDLE COMPARING WITH LITERATURE. THIS METHODS ARE IMPLEMENTED IN CAST3M A NUMERICAL PLATFORM OF FRENCH NUCLEAR AGENCY - CEA-SACLAY -.