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ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

OSCILLATORY FLOW TRANSITION OF THERMOCAPILLARY CONVECTION IN A MELTED POOL

Get access (open in a dialog) DOI: 10.1615/IHTC10.1660
pages 91-96

Sinopsis

A two-dimensional laser surface remelting problem is numerically simulated The mathematical formulation of this multiphase problem is obtained using a continuum model, constructed from classical mixture theory. This formulation permits to construct a set of continuum conservation equations for pure or binary, solid-liquid phase change systems. The numerical resolution of this set of coupled partial differential equations is performed using a finite volume method associated with a PISO algorithm. The numerical results show the modifications caused by an increase of the free surface shear stress (represented by the Reynolds number Re) upon the stability of the I hermocapillary flow in the melting pool. The solutions exhibit a symmetry - breaking flow transition, oscillatory behavior at higher values of Re. The spectral analysis of temperature and velocity signals for particular points situated in the melted pool, show that these oscillations are at first mono -periodic then new frequencies appear generating a quasi -periodic behavior. These oscillations of the flow in the melted pool could induced the deformation of the free surface which could explain the formation of surface ripples observed during laser surface treatments (surface remelting, cladding) or laser welding.