Force measurement in heaving and pitching foils

This study analyzes the efficiency of a cambering hydrofoil built to simulate the movement of flukes on cetaceans. The mechanism is a 10 bar assembly that allows a hydrofoil to move in a cambered pitching and heaving motion similar to that of a dolphin. The mechanism sits on a force-balance with six strain gages that together measure the three forces and three moments experienced by the fin during a cycle of motion. These gages are attached to a traveling mechanism that rest on a water flume. To analyze the efficiency of the hydrofoil we took measurements at various Reynolds and Strouhal numbers. These measurements were done twice were compared to the thrust produced by a rigid (non-cambered) hydrofoil at the same conditions.