Ebook: Helicopters. Calculation and Design. Volume I. Aerodynamics

Washington: National Aeronautics and Space Administration, 1967. - 506 p.Translation of "Vertolety . Raschet i proyektirovaniye.
Aerodinamika." Izdatel'stvo Mashinostroyeniye, Moscow, 1966.
The work "Helicopters (Calculation and Design)" is published in three volumes.
Aerodynamics;
Vibrations and Dynamic Strength;
Design.
The first volume is devoted to ways of developing helicopters, the basic principles of their design, and the position occupied by helicopters among other means of aviation not requiring airfields. Various theories of rotors and corresponding methods of determining their aerodynamic characteristics are presented: the classical theory of a rotor with hinged blades in the general case of curvilinear flight of the helicopter; the momentum theory of an ideal rotor and its application to the energy method of calculation; the classical theory when using methods of numerical quadrature; the vortex theory and methods of experimental determination of rotor performance in flight tests and in wind tunnels. Various methods of aerodynamic calculation of a helicopter and the theory of blade flutter are presented in detail. This volume gives an account of methods of calculating flutter in hovering and in forward flight. Particular attention is devoted to consideration of friction in the axial hinges of the hub and to the transfer of blade vibrations through the automatic pitch control mechanism. Experimental investigations of flutter are described.
The book is intended for engineers of design offices, scientific workers, graduate students, and teachers of higher institutes of learning. It might be useful to engineers of helicopter manufacturers and to students for furthering their knowledge of the aerodynamics and mechanical strength of helicopters. Many sections of the book will be a useful tool also to flight and technical staffs of helicopter flight units.