Natural Convection Heat Transfer in Two-Dimensional Semicircular Slice Pool

Abstract

This paper presents results from the Mini-SIGMA (Simulation of Internal Gravity-driven Melt Accumulation) tests concerned with high Rayleigh number turbulent natural convection in a molten pool. Tests are conducted to check on functionality of a custom-designed heater and to obtain correlations in terms of the Rayleigh and Nusselt numbers. The internal heating method is adopted in the tests utilizing the cable-type heater. This study concentrates on the thermal load, angular heat flux distribution, and temperature distribution inside the molten pool. The test section is a two-dimensional slice whose diameter, height, and thickness are 250 mm, 125 mm, and 50mm, respectively. The pool's curved wall, with a 23 mm thick copper plate, is cooled by a regulated water loop. A water-cooling system is used to maintain the temperature of water surrounding the test section as constant as practicable with time. Four thin cable-type heaters, each with a diameter of 2.4 mm and a length of 900 mm, are used to simulate internal heating in the pool. They are uniformly distributed in the semicircular section to supply a maximum of 1 kW power to the pool. The Rayleigh number is obtained from these test data up to 1010.