Enhanced Thermal-Hydraulic Performance of a Wavy-Plate-Fin Compact Heat Exchanger: Effect of Corrugation Severity

Enhanced forced-convective heat transfer behavior of air flows (Pr ~ 0.7) in a compact heat exchanger with three-dimensional, sinusoidal-wavy-plate fins is investigated both experimentally and computationally. Plate-fins with three different corrugation aspect ratio γ = (2A/L) = 0.0667, 0.1333, and 0.2667 are explored. Experimental j and f measurements are presented for flow rates in the range 500 < Re < 5000. Computational results, based on control-volume techniques, are obtained for periodically-fully-developed flows with 10 ≤ Re ≤ 1000. The numerically simulated local temperature and flow field map shows the complex influence of corrugation aspect-ratio γ, and the concomitant j and f predictions are in good agreement with experimental measurements. Both j and f increase with γ to reflect the relatively stronger flow recirculation in the wall-trough regions, and spatially more frequent periodic boundary-layer disruptions upstream of the corrugation peaks that enhance heat transfer in plate-fin channels. The relative enhancement, as measured by the Area Goodness Factor (j/f), however is found to be highest with γ = 0.0667.