DOI: 10.1615/ICHMT.1995.RadTransfProc
ISBN Print: 978-1-56700-068-9
ISSN Online: 2642-5629
ISSN Flash Drive: 2642-5661
RADIATION-CONVECTION INTERACTIONS IN SOLIDIFICATION OF SEMI-TRANSPARENT CRYSTALS
要約
Radiation exchange in semitransparent crystals often dominates heat transfer during the growth process. A combined conduction-convection-radiation model is presented for solidification of two important oxide crystals BSO and YAG which are transparent to radiation below 6 microns and opaque to radiation in the rest of the spectrum. The numerical model tracks the solidification front and as the geometry changes, the necessary exchange factors for computing radiation heat transfer inside the crucible are updated. Numerical results show that, for both materials, radiation is the dominant heat transfer mechanism through the solid crystal. Nonuniform radiative loss from the solidification front determines the shape of the interface and increases its curvature significantly. The extent of the interface stretching and its curvature depend strongly on the value of the refractive index. Numerical simulations indicate that the flow structure in the melt is also indirectly affected by radiation heat transfer.