Numerical Study of stall delay on humpback whale flippers

The low Reynolds numbers (< 5 × 10) flows over wings have some unique features specially concerning separation. A comprehensive knowledge about this flight regime is extremely important for the autonomous aircrafts (UAV), since a large percentage of these vehicles operated in this regime. In this report we simulate numerically the wind-tunnel experiments for two different wings inspired in the humpback whale flipper. One of the flippers displays a scalloped leading edge whereas the other one has a smooth leading edge. The experimental study revealed a significant increase in the aerodynamic performance for the scalloped flipper close to the separation. The detailed numerical solution allows for the complete characterization of the flow for both flippers. The simulated Reynolds is (5 × 10) which allowed for the visualization of some of the low Reynolds effects. The comparison between the two geometries gives some indications about how to improve the aerodynamic performance of UAV’s wings.