Two-phase flow, Superhydrophobic surfaces, Drag reduction


Superhydrophobic surfaces have been shown to reduce drag in single-phase channel flow; however, little work has been done to characterize their drag-reducing ability found in two-phase flows. Adiabatic, airwater mixtures were used to explore the influence of hydrophobicity on two-phase flows and the hydrodynamics which might be present in flow condensation environments. Pressure drop measurements in a rectangular channel with one superhydrophobic wall (cross-section approximately 0.37 x 10 mm) and three transparent hydrophilic walls were obtained. Data for air/water mixtures with superficial Reynolds numbers ranging from 22–215 and 55–220, respectively, were obtained for superhydrophobic surfaces with three different cavity fractions. Agreement between experimentally obtained two-phase pressure drop data and correlations in the literature for conventional smooth control surfaces was better than 20 percent, which is within the accuracy of the correlations. The data reveal a reduction in the pressure drop for two-phase flow in a channel with a single superhydrophobic wall compared to a control scenario. The observed reduction is approximately 10 percent greater than the reduction that is observed for single-phase flow (relative to a classical channel).

Original Publication Citation

Stevens, K., Crockett, J., Maynes, R. D., and Iverson, B. D., 2017, "Two-phase flow pressure drop in superhydrophobic channels," International Journal of Heat and Mass Transfer, Vol. 110, pp. 515-522.

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Peer-Reviewed Article

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Ira A. Fulton College of Engineering and Technology


Mechanical Engineering