Microbubble Drag Reduction at High Reynolds Number

This paper presents the preliminary results from a friction drag reduction experiment conducted at high Reynolds numbers. The experiments were conducted in two phases at the U. S. Navy’s William B. Morgan Large Cavitation Channel (LCC) in Memphis, TN on a flat, hydraulically smooth plate (12.9 meters long by 3.0 meters wide by 0.18 meters thick) at flow speeds ranging from 0.5 to 20 m/s. The employed drag reduction technique involved the injection of microbubbles into the boundary from a line source over a range of injection flow rates from 100 to 800 scfm. These results include mean velocity data and spatially averaged shear stress data acquired in the single-phase flow, as well as spatially averaged shear stress data, bubble images, and void fraction measurements made in the bubble-injected flow.