31 March 1995 Oscillatory flow transition and thermocapillary convection during laser surface treatment
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Proceedings Volume 2502, Gas Flow and Chemical Lasers: Tenth International Symposium; (1995) https://doi.org/10.1117/12.204985
Event: Gas Flow and Chemical Lasers: Tenth International Symposium, 1994, Friedrichshafen, Germany
Abstract
A 2D 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 thermocapillary 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.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
D. Morvan, D. Morvan, Philippe Bournot, Philippe Bournot, } "Oscillatory flow transition and thermocapillary convection during laser surface treatment", Proc. SPIE 2502, Gas Flow and Chemical Lasers: Tenth International Symposium, (31 March 1995); doi: 10.1117/12.204985; https://doi.org/10.1117/12.204985
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