Standing-oscillatory natural convection computed for molten silicon in Czochralski configuration

Numerical computations were carried out for transient natural convection in molten silicon (Pr = 0.016) in a relatively shallow crucible heated on the wetted surface and cooled by a crystal rod and at the free surface. At Ra = 10(5), six separate roll cells appeared with triangular isotherms. In eac h cell, a coaxial double spiral streak line was found to exist. At Ra = 10( 6), the convection became oscillatory with eight peak temperatures in a cir cumferential direction. The oscillation was found to consist of simultaneou s movement of the roll cells in both the vertical and circumferential direc tions. (C) 1998 Elsevier Science S.A. All rights reserved.