An experimental study of an airfoil undergoing cycloidal motion

Abstract

Experimental data were obtained for several sets of airfoils moving along cycloidal paths into an otherwise still fluid. This configuration can be used to simulate a two dimensional Darrieus turbine. In this experiment the rotor was towed through a tank filled with water. The use of water instead of air as a working fluid facilitated both the ability to measure aerodynamic blade forces and the utilization of flow visualization techniques. Well-known scaling laws were used to relate the operation in water to that in air. Flow visualization techniques using dye injection and solid particle markers were used to examine details of the flow structure. These details were compared, along with blade loading measurements to predictions of an analytical model developed as a joint part of this effort.