NATURAL-CONVECTION BETWEEN A VERTICAL CYLINDER AND A SURROUNDING ARRAY

The generic situation considered is natural convection between a singl e heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temp erature to the cooling tube temperature was varied up to 2.6 by adjust ing the electrical power. The Rayleigh number, based on test section d iameter and air properties evaluated at cooling tube temperature, rang ed from 2.9 X 10(4) to 4.6 X 10(5). Results indicate that the convecti ve heat transfer data could be approximated as Nu(D)(T(ts)/T(ct))0.14 = 0.156 Ra(D)1/3 in the apparent turbulent region for Ra(L) > 1.2 X 10 (11).