Comparative study of required power of coaxial rotor and equivalent single rotor at the hover and forward flight modes
https://doi.org/10.26467/2079-0619-2026-29-2-121-132
Abstract
A coaxial main rotor (MR), consisting of upper (UR) and lower (LR) rotors with a spacing of planes and a different direction of rotation, has a number of advantages in aerodynamic characteristics compared to an equivalent single rotor of the same radius, having a double number of blades and solidity. The equivalent MR model is often used in approximate methods of aerodynamic calculation. In this case, the features of the coaxial MR are taken into account using special corrections. This requires data on the coaxial and equivalent MR aerodynamic characteristics in various operating modes. The article is dedicated to comparative study of the coaxial and equivalent MR aerodynamic characteristics. The Ka-226 helicopter coaxial MR is considered. The research was performed on the basis of the free vortex wake model of a rotor. The modes of hovering and forward flight in the speed range of V = 0–60 m/s were considered. The calculations were performed taking into account the rotor trim and compensation of aerodynamic loads occurring on the helicopter airframe, assumed to be the same for both rotors. It was found that the required power of a coaxial MR at hovering (V = 0) is 6% less than that of an equivalent MR with equal thrust. At V = 20 m/s, the advantage of the coaxial MR reaches 8%, and then gradually decreases. At V > 60 m/s, the required power of the coaxial and equivalent MR, all other things being equal, does not differ. The results obtained complement the available information on the features of the coaxial and equivalent MR aerodynamics and can also be used to refine approximate methods for calculating flight performance and flight dynamics models of coaxial helicopters using the equivalent MR model.
About the Author
P. V. Makeev
Moscow Aviation Institute (National Research University)
Russian Federation
Russian Federation
Pavel V. Makeev, Candidate of Technical Sciences, Associate Professor, Associate Professor of the Design and Certification of Aviation Equipment Chair
Moscow
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For citations:
Makeev P.V. Comparative study of required power of coaxial rotor and equivalent single rotor at the hover and forward flight modes. Civil Aviation High Technologies. 2026;29(2):121-132. (In Russ.) https://doi.org/10.26467/2079-0619-2026-29-2-121-132
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