Meeting Abstract

79-4  Sunday, Jan. 6 08:45 – 09:00  Computational fluid dynamics simulations of a 10m North Atlantic right whale (Eubalaena glacialis) WU, C*; HOWLE, LE; MCGREGOR, AE; MCGREGOR, R; NOWACEK, DP; Marine Science and Conservation, Duke University, USA; Mechanical Engineering and Materials Science, Duke University, USA; School of Life Sciences, University of Glasgow, UK; High Def Aerial Surveying Ltd, UK; Marine Science and Conservation, Duke University, USA chen.yi.wu@duke.edu

Drag occurs when an object moves through a fluid due to the viscosity of the fluid. Accurate estimations of drag on marine animals are required if one wants to investigate the locomotive cost, the propulsive efficiency, and, in our case, the impacts of entanglement while the animal is carrying fishing gear. In this study, we performed computational fluid dynamics (CFD) analysis over a 10m (length of animal, LOA) static right whale model in a commercial flow solver (SolidWorks Fluid Simulation 2015) to obtain baseline measurements of drag on the animal. Swimming speeds covering known right whale speed range (0.125 m/s to 8 m/s) were tested. We found a weak dependence between drag coefficient and Reynolds number. At a swimming speed of 2 m/s, we analyzed the boundary layer thicknesses, the flow regimes, and drag components. We found the thickest boundary layer at the lateral sides of the peduncle whereas the boundary layer thickness over the outer part of the flukes was less than 1.7cm. Laminar flow occurred over the anterior ~0.6 LOA and fully turbulent flow from ~0.8 LOA to the fluke notch. On surfaces of the flukes outside of the body wake region, flow was laminar. Our most significant finding is that the drag coefficient (0.0071-0.0059) of a right whale, which is associated with the morphology the animal, for swimming speeds ranging from 0.25 m/s to 2 m/s is approximately twice that of many previous drag coefficient estimates for cetaceans.