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ISSN Online: 2377-424X

ISBN Print: 0-89116-909-1

International Heat Transfer Conference 9
August, 19-24, 1990 , Jerusalem, Israel

THERMOCAPILLARY CONVECTION DURING LASER SURFACE TREATMENT A NUMERICAL STUDY

Get access (open in a dialog) DOI: 10.1615/IHTC9.1500
pages 381-383

要約

A two-dimensional numerical model concerning the Laser surface melting of material is presented. The hydrodynamical and thermal problems, which include a phase-change zone, are solved using a fixed grid method. The basic feature of the proposed method lies in the representation of the melted material in the solid liquid mushy zone as a flow in a porous medium. This can be obtained by the addition of suitably chosen source terms in dynamical equations which introduce progressively this particular behaviour. The energy absorbed or released during the phase change is enclosed by the enthalpy formulation for the energy equation. The convective flow which expands in the melted pool is induced by thermocapillary effects (Marangoni convection) which modify the heat flow in the work piece and the dimensions of the thermal affected zone. The authors have studied numerically the influence of experimental conditions, as Laser power distribution and scanning velocity of the Laser beam, on the intensity of thermocapillary convection cells. The flow pattern and the modification introduced by the convective motions on the heat flow are represented by streamlines and isothermal plots which can be compared with the results obtained for a purely conductive problem.