Flow Visualization of Dolphin Swimming Using Bioluminescent Marine Plankton

摘要

Interest in visualizing the flow field around a swimming dolphin is motivated byspeculation that dolphins are able to maintain laminar boundary layer flow at Reynolds numbers (ReL l0 7) significantly higher than those achieved by man-made vehicles. This possibility was first proposed by Sir James Gray as a result of a comparison analysis of the propulsive powers of a dolphin. Over the last 50 years many 'resolutions' to Gray's paradox have been proposed, including: greater estimates of available muscle power for burst speeds, smaller estimates of burst speed, novel low drag hypothese, as well as a fundamental reevaluation of the paradox in terms of the efficiency of the propulsive mechanism. Whether the flow over a dolphin is laminar or turbulent, we address this subject using a novel flow visualization technique.