Laminar Flow Across a Bank of Low Aspect Ratio Micro Pin Fins

Pressure drops and friction factors associated with the forced flow of de-ionized water over staggered and in-line circular/diamond shaped micro pin-fin bundles 100μm long with hydraulic diameter of 50 and 100μm have been experimentally investigated over Reynolds number ranging from 5 to 128. Pin fins were arranged according to two different horizontal and vertical pitch ratios (1.5 and 5). The applicability of conventional scale correlations to evaluate micro flow tests results has been assessed. It is shown that the available large-scale correlations do not adequately predict the pressure drop obtained at the micro scale. A modified correlation, based on the experimental results obtained using micro scale devices, has been proposed. The refined correlation accounts for fin density and the endwall effects encountered in micro scale configurations.