Laminar Flow in the Open Thermosyphon, with Special Reference to Small Prandtl Numbers

Abstract

By use of approximate methods, the rates of heat transfer are predicted for laminar flow due to natural convection in heated vertical cylinders closed at the lower end and opening at the top into a reservoir of cool fluid. Most interest is shown in the flow found for small values of Prandtl number associated with mercury and liquid metals. The type of flow is found to depend upon the Prandtl number as well as the product of the Rayleigh number and radius/length ratio.