Experimental Study of the Steady Natural Convection in a Horizontal Annulus with Irregular Boundaries

摘要

The natural convective heat transfer across an annulus with irregular boundaries was studied using a Mach-Zehnder interferometer. The annulus was formed by an inner hexagonal cylinder and an outer concentric circular cylinder. This configuration models, in two dimensions, a liquid metal fast breeder reactor spent fuel subassembly inside a shipping container. During the test, the annulus was filled with a single gas, either neon, air, argon, krypton, or xenon, at a pressure of about 0.5 MPa. From temperature measurements, both local and mean Nusselt numbers (Nu/sub delta /) at the surface of the inner cylinder were evaluated, with the mean Rayleigh number (anti Ra/sub delta /) varying from 4.54 x 10 exp 4 to 0.915 x 10 exp 6 ( delta is the local gas width). The data correlation for the mean Nusselt and Rayleigh numbers is given by anti Nu/sub delta / = 0.183 anti Ra/sub delta / exp 0 exp 310 . (ERA citation 05:026230)