29-08-2017, 02:45 PM
Helicopters are extremely versatile vehicles that have many unique capabilities not available for fixed wing aircraft. However, helicopters are ineffective in flying forward with respect to a fixed wing aircraft. The fastest production helicopter, the Westland Lynx, has the helicopter's record speed of 216 knots, or about 250 mph, while commercial jets regularly cruise efficiently at speeds of over 600 mph. One of the challenges for efficient forward flight in helicopters is the rapid increase in induced power at high speeds, in part because of the need to maintain the roll cut. Previous studies have shown that composite helicopters, such as the coaxial rotor used in the X2 technology demonstrator or the wing rotor system used in the Cheyenne helicopter, offer large power reductions relative to conventional single-rotor helicopters.
We are investigating the optimal aerodynamic design of the rotor for conventional and composite helicopters. This includes determining the rotation of the blade, chord, and root entrances that produce the most efficient flight. We are also exploring the benefits of higher harmonic root control to reduce power. The control of the conventional cyclic plate presents a cyclic step variation of 1 / rev. Previous research has shown that greater harmonic control (2 / rev, 3 / rev, etc.) can provide benefits both in terms of vibration suppression and power reduction.
We seek to develop computationally efficient methods that can serve as useful tools in the conceptual or preliminary design phases, as well as gain insight into the underlying aerodynamics of the helicopter's rotor.
We are investigating the optimal aerodynamic design of the rotor for conventional and composite helicopters. This includes determining the rotation of the blade, chord, and root entrances that produce the most efficient flight. We are also exploring the benefits of higher harmonic root control to reduce power. The control of the conventional cyclic plate presents a cyclic step variation of 1 / rev. Previous research has shown that greater harmonic control (2 / rev, 3 / rev, etc.) can provide benefits both in terms of vibration suppression and power reduction.
We seek to develop computationally efficient methods that can serve as useful tools in the conceptual or preliminary design phases, as well as gain insight into the underlying aerodynamics of the helicopter's rotor.