HEAT-TRANSFER AND PRESSURE-DROP CHARACTERISTICS OF 10 RADIATOR TUBES

The thermal and hydraulic performance of ten radiator tubes has been i nvestigated. The tubes tested are one smooth tube, two rib-roughened t ubes, five dimpled tubes and two offset strip fin tubes. The tubes are representative of flat tube geometries applied in automotive heat exc hangers, for example radiators. Isothermal pressure drop data were tak en for Reynolds numbers in the range of 500-6000. These data are prese nted as Fanning friction factors and inlet loss coefficients. Heal tra nsfer data were taken in the same Reynolds number range and the result s are presented as Colburn j factors, as well as Nusselt numbers. The tubes are compared by considering the flow area goodness factor and th e volume goodness factor. The rib-roughened tubes showed the best perf ormance. The offset strip fin tube results could be correlated within 20% by correlations available in the literature. For all tubes, simple correlations of the results are provided. Copyright (C) 1996 Elsevier Science Ltd.