Aerodynamic interference characteristics of a new compound configuration helicopter

By combining the characteristics of high hovering performance and control efficiency of coaxial-rotor helicopters and the advantage of high-speed forward flight performance of double-thrust-propeller compound configuration helicopters, the coaxial rotor was applied to the double-thrust-propeller compound configuration helicopter. The single rotor was changed to a coaxial rotor based on the configuration of the X3 compound helicopter. To study the influence of coaxial rotors on the aerodynamic characteristics of compound configuration helicopters, a fast trim method was established. On this basis, the aerodynamic characteristics of different configuration helicopters were analyzed. The results indicate that the aerodynamic characteristics of the coaxial-rotor helicopter have good symmetry compared with the single-rotor configuration. In the case of maintaining good high-speed forward flight performance, the coaxial-rotor configuration can significantly improve the hovering and low-speed flight performance. When the hovering efficiency is increased by 6.8%, and the forward flight speed is 100 km/h, the total required power is reduced by 23.1%. The aerodynamic interference of the coaxial rotor to the propeller at low speeds is greatly lower than that of the single rotor.