Effects of Nonuniform Passages on Deepfold Heat Exchanger Performance

Abstract

To realize the maximum convective transfer of heat or mass, the fins in a plate-fin type heat exchanger must be exactly spaced for an unsupported length at least eight times the fin spacing. Manufacturing tolerances cause imperfect fin spacing and fin shape. These imperfections have been statistically modeled as either nonuniform fin spacing or “bulginess.” By statistically combining nonuniform fin spacing and bulginess into a unique “total channel deviation” parameter, convective transfer penalties and flow pressure drop gains can be predicted. Predictions are supported by experimental measurements.