Marangoni flow regimes in liquid metals

Abstract

Marangoni flows in liquid metals are studied in two complementary ways: 1. 1. An order of magnitude analysis of the flow regimes is performed on the basis of the concepts of the boundary layer theory, as previously performed for the case of buoyancy driven flows in Bridgman solidification. This analysis is applied to the case of a planar liquid layer under 1 g conditions. Particularly, the parameter range (layer thickness d and thermal gradient G) under which pure Marangoni flows can be observed at 1 g is thus determined. 2. 2. An experimental method is developed to measure the velocities of inert particles at the surface of thin liquid metal layers at 1 g. Experimental results for liquid tin with 0.3 < H < 4 mm and 5 < G < 40 K/cm are reported, and their consistency with the predicted scaling laws is discussed.