Meeting Abstract

P3.14  Thursday, Jan. 6  Swimming hydrodynamics at intermediate Reynolds numbers in water boatmen NGO, V.*; MCHENRY, M.J.; Univ. of California, Irvine vngo3@uci.edu

A tremendous diversity of swimming animals are a few millimeters in length. Understanding the fluid dynamics at this scale is complicated because neither viscous nor inertial forces may be assumed to be negligible. In order to resolve the relative importance of these fluid forces, we tested a hydrodynamic model of swimming in water boatmen (Corixa punctata) that range in size from about 1 to 10 mm and generate a more than 20-fold range of intermediate Reynolds numbers. The model that we evaluated uses a blade-element approach. Our measurements of the shape and high-speed kinematics of the propulsive legs provided parameters for this model to calculate thrust. Simulations considered this force,the body mass, and drag to calculate changes in the speed and position of the center of mass over time. We found that the model accurately predicts the kinematics of the center of mass over a range of body sizes. The forces predicted by the model indicate differences in the hydrodynamics of swimming for species over their range of sizes.