Optimizing foil shape for fish-like propulsion Part I: Experimental performance*

Fish have a remarkable ability to swim with high speed and efficiency. Typically, swimming animals use an unsteady foil-like tail or fin to propel themselves. Recent findings suggest that the quasi-steady drag of a foil impacts the peak swimming efficiency because it acts as an offset to the thrust produced. Here we optimize the foil shape computationally in XFOIL to minimize drag under a range of steady angles of attack for Reynolds numbers 1x10^5 to 10x10^5. These results guide our experiments, where we explore the impact of foil shape on fully-unsteady fish-like propulsion characteristics, and also will compliment unsteady simulations conducted by collaborators at the University of Virginia.