An experimental investigation of a staggered array of heatsinks in the hydrodynamic and thermal entrance regions of a duct

Experimental research was carried out to develop correlations that can be used to predict heat transfer coefficients and thus temperatures of electronic packages in a staggered array in the hydrodynamic and thermal entrance regions of a duct. The ten components in the array are mounted on one wall of the duct to simulate a printed circuit board in a card cage. Results are presented for three values of Reynolds number (20250, 50000, and 65000) for a range of H/B (duct height to package height ratio) from one to five by increments of two while L/D (longitudinal to latitudinal spacing) is varied from one to three by increments of 0.5. Comparisons are made between upstream and downstream packages. It was determined that one correlation could be used to predict the Nusselt number for upstream heatsinks. This correlation is a function of Reynolds number and H /B. The results also indicate that three correlations are necessary to predict the Nusselt number of downstream heatsinks