Velocity and temperature fields in gas-cooled rod bundles

Measurements were made of the velocity and temperature fields in an air flow along a bundle of 7 heat generating rods arranged in a triangular array with a pitch of 1.35 inside a smooth and adiabatic hexagonal shell with displacers; the surface of the rods was roughened with microscopic elements of trapezoidal form. It was found that for the most part the flow was displaced to the cells around the periphery of the bundle, the more so, the greater the heating of the rods. The application of the equivalent ring method to the analysis of the tests allowed the development of the technique to determine the pressure drop in a channel with a mixed, partially smooth and partially rough, surface