Directional stability of foils and swimming performance measures
Bill Schultz, University of Michigan


This will be an informal conversation about ongoing and proposed future experiments and analyses of swimming.  As such, it will raise more questions than answers. Among those questions are: How can we best determine the directional stability of (rigid and swimming) foils?  How much of swimming stability can be captured by a 2D potential flow analysis of a Joukowsky airfoil? What constraints does this make on experiments?  Can a Floquet-type analysis  be performed for a periodically deforming (swimming) foil? To what extent can an energetics analysis measure swimming performance in replacement of Froude-efficiency arguments?  Answering these questions will determine if fish can sleep while migrating and how they might optimize burst and coast gaits.