In January, scientists of the Central Aerohydrodynamic Institute named after Professor N. E. Zhukovsky (part of the NRC “Institute named after N. E.Zhukovsky”) discussed the problems of the helicopter at the meeting of the research seminar of the Department of aerodynamics and dynamics of helicopters, spin and aerodynamics of aircraft at high angles of attack.
Specialists of the Institute have presented research in the field of rotorcraft, including on the subject of high-speed helicopters. An example is the study of the scheme of rotary wing aircraft with a stop in flying rotor-wing. Details of these achievements described in the report of the leading engineer of the Department of aerodynamics and dynamics of helicopters, spin and aerodynamics of aircraft at high angles of attack the FGUP TSAGI Valery Gorban.
“Significant restrictions speed capabilities of the helicopter are determined by the aerodynamic properties of the traditional rotor. Effective way of solving this problem could be stopped in flight the rotor wing. During vertical takeoff, it works like a normal rotor, then, after dialing a certain speed, the screw stops and then works like a traditional airplane wing, providing the opportunity to substantially increase the speed of flight. A key difficulty in the implementation of this scheme is to ensure the stability and controllability of the aircraft at the moment of transition from “helicopter” flight mode to “airplane” and back. In the Institute we have developed several technical solutions that we hope will help to cope with the described problem,” — said Valery Gorban. Last autumn snap in the wind tunnel of the Institute was tested, experimentally confirmed the possibility of stable and efficient operation of the carrier system of the apparatus with stop screw-wing on such transient conditions. The application of this concept, according to preliminary estimates of specialists, able to increase the maximum speed of the helicopter from 400 to 600-700 km/h.
Another way of solving the problem of creating a high-speed single-rotor helicopters with articulated rotor has been presented in the report by the acting head of the Department of aerodynamics and dynamics of helicopters, spin and aerodynamics of aircraft at high angles of attack FGUP “TSAGI” Yevgeny Borisov. He spoke about studies of helicopter rotor with negative removal of the horizontal joints. “In many cases, disrupting the flow with the retreating main rotor blades is the main obstacle to increase the speed of flight of a single-rotor helicopter, as it leads to a deterioration of the aerodynamic characteristics of the rotor, a sharp increase in loads in the control system and increase the vibration of the helicopter. The most effective method of solving the problem of flow separation is the use of different methods increases the aerodynamic load on the advancing blade and decrease it on the retreating”, — said the scientist. According to him, increasing the load on the advancing blade and decrease it on the retreating leads to an increase of the lateral moment of the helicopter, to compensate for which you want to apply additional solutions. TSAGI proposed a new concept of the rotor with a negative removal of the horizontal joints, which allows you to balance the single-rotor helicopter at high flight speeds without the use of additional structural solutions.
Meeting of the scientific-technical seminar on problems of the helicopter are held regularly — twice a month. The event is organized by TSAGI and is held at the site of the Department of aerodynamics and dynamics of helicopters, spin and aerodynamics of aircraft at high angles of attack. To participate in the seminar representatives of JSC “Kamov”, JSC “mil im. Ml Mile” and other enterprises specializing in the research and development of helicopters.