Generating optimum hovering behavior
As far as the rotor tips were concerned, the researchers used Simcenter Star-CCM + simulations to investigate the effect of the tip shape on the hovering performance of a Sikorsky S-76 baseline rotor. The result shows that rotors with an anhedral tip produce the best performance. Other studies on anhedral tip shapes are in progress.
Anhedral = negative V-position in the aircraft. This reduces the inherent stability of the aircraft, but increases maneuverability and the achievable roll rate.