BUOYANCY, LOCOMOTION, AND MOVEMENT IN FISHES | Experimental Hydrodynamics

Abstract

Fish physiologists use experimental hydrodynamics techniques to visualize and quantify the way water moves around swimming fishes. Studying water motion provides information about forces that fishes produce, along with external forces, such as eddies, for which they must compensate. This article introduces the basic principles of fluid dynamics necessary for understanding such measurements, and describes several standard techniques for measuring and interpreting fluid flow fields. Special emphasis is given to planar flow fields, such as those estimated using the technique called particle image velocimetry. Both vortex and momentum-based techniques for estimating force from flow patterns are described.