Rotor for developing sustaining and propelling forces in a fluid, steering process, and aircraft equipped with such rotor

A process for controlling a rotor connected to an airframe movable in a fluid, for exerting at each instant on said airframe sustaining and/or propelling forces desired, said rotor comprising a carrier structure (5, 10, 11) mounted on said airframe (1) in such a manner as to be able to be rotationally driven about an axis of rotation (O) and at least one profiled blade (9) extending parallel to the axis of rotation (O) and articulated on said carried structure by a pivot connection on the axis (8) essentially parallel to said axis of rotation (O) at a rotational speed (.omega.), and being characterized in that it comprises:

• preliminarily storing data representative of the following structural parameters of the rotor:
• nE (the equivalent wingspan equal to the product of the number of profiled blades n of the rotor and the spread E of each profiled blade);
• R (the distance between the axis of rotation O and the axis B of the pivot connection);
• r (the distance on the chord of the profiled blade between the axis B and a point P situated essentially one quarter to the rear of the profile);
• a (coefficient of the congruent transformation of the profiled blade);
• ##EQU14## where a.sub.1, a.sub.2 . . . a.sub.i are the terms of the congruent transformation developed in the Laurent series, A.sub.-1, A.sub.1, . . . A.sub.i are the terms of the product of the congruent transformation and its conjugate developed in the Laurentian series and S the surface normal to the profile,
• measuring and determining at each instant the relative speed (V) of displacement of the airframe with respect to the fluid, the speed of rotation .omega. of the rotor and the volumic mass .rho. of the fluid from measurements of the dynamic pressure, the static pressure and the temperature of the fluid,
• measuring and permanently determining during rotation, the aerodynamic azimuth .phi. of each profiled wing for generating a corresponding measurement signal, said aerodynamic azimuth being the algebraic angle formed by the direction of the relative wind and the plane M containing the axis of rotation O and the axis B of the pivot connection of the profiled wing considered,
• generating reference signals representative of the desired forces on the airframe (algebraic forces translated by their projections P and T respectively according to a direction perpendicular to the relative wind and according to the direction of the relative wind),
• determining permanently, for each profiled wing, from the stored parameters, from the measured and determined values, and from the reference signals, the instantaneous geometric angle .PSI. defined by the chord of the profiled wing and by the plane M corresponding to within .+-.0.2 radians to the following relationships (all angles being defined in the trigonometric sense):
• ##EQU15## and controlling the instantaneous geometric angle of each profiled wing at the value of the angle .PSI. obtained for said wing.