The thermal-hydraulic impact of delta-wing vortex generators on the performance of a plain-fin-and-tube heat exchanger

This paper reports on experiments to evaluate the effectiveness of delta-wing vortex generators applied to fin-and-tube heat exchangers. For air flowing at Reynolds numbers from about 700 to 2300, Colburn j and friction factor f data are obtained for a conventional refrigerator evaporator with and without a single row of delta-wing vortex generators placed at the inlet face of the test heat exchanger. Colburn j factor enhancements up to 31% over the baseline were obtained, without any pressure-drop penalties. The data confirm the promise for this method of heat transfer augmentation in plain-fin-and-tube heat exchanger applications, and provide a basis for improving heat exchanger performance.