OSCILLATORY NATURAL-CONVECTION OF A LIQUID-METAL IN CIRCULAR-CYLINDERS

An experimental study is made of natural convection oscillations in ga llium melts enclosed by right circular cylinders with differentially h eated end walls. Cases heated from below are examined for angles of in clination (phi) ranging from 0 deg (vertical) to 75 deg with aspect ra tios Ar (height/diameter) of 2, 3, and 4. Temperature measurements are made along the circumference of the cylinder to detect the oscillatio ns, from which the oscillatory flow structures are inferred. The criti cal Rayleigh numbers and oscillation frequencies are determined. For A r = 3 and phi = 0 deg, 30 deg the supercritical flow structures are di scussed in detail.