Heat Transfer in Beds of Oriented Spheres [Thesis]

Experiments have been performed to show how the fluid-solid heat transfer at various positions in beds of oriented spheres is influenced by a jet which impinges on the first row. Heat transfer coefficients have been determined at several radial and axial positions in two arrangements of 1 15/16 inch spheres. One was a regular cubic arrangement with a void fraction of 0.478 and the other was a dense cubic orientation with a void fraction of 0.261. The heat transfer medium was pressurized water at about 240°F and a Reynolds number range of 3,000 to 70,000 was covered. The coefficients for individual spheres in the front rows of both beds have been found to be influenced strongly by the radial position and the nature of the entering jet. The effect appeared to be dissipated completely ahead of the fifth row of the regular cubic bed and the third row of the dense cubic bed. Beyond these rows, over the entire range of Reynolds numbers investigated, the regular cubic arrangement yielded the relationship j_H = 0.992 Re^-0.33 and the dense cubic arrangement yielded j_H = 0.940 Re^-0.30.