Full Description

This paper presents the results of an experimental study of pressure drop and heat transfer for turbulent flow inside 12 different doubly-fluted tubes. All the tubes used in the study were fabricated from a single base tube using a single manufacturing process and represent a range of geometries. The experiments covered a range of Reynolds numbers from 10,000 to 100,000. All the data were obtained using water flowing inside a horizontal tube with steam condensing on the external surface of the tube. Internal convective heat transfer and external condensation coefficients were obtained using a modified Wilson-plot technique. Friction factor and Nusselt number correlations are presented for each tube. The performance of the tubes is examined by determining the volume reduction that can be achieved using doubly-fluted tubes. Volume reductions of 20% can be achieved for designs where the tubeside resistance is limiting.

Units: Dual

Citation: Symposium, ASHRAE Transactions, 1987, vol. 93, pt. 2, Nashville, TN