US 2020/0049127 A1Published application

Method For Designing A Wind Turbine Or A Water Turbine Blade

AssigneesUniversite Paris Diderot—Paris 7, Ecole Superieure De Physique Et De Chimie Industrielles De La Ville De Paris, Centre National de la Recherche Scientifique (CNRS), Universite Pierre Et Marie Curie (Paris 6)

InventorsVincent Cognet, Sylvain Courrech Du Pont, Benjamin Thiria

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Abstract

The invention relates to a method for designing a flexible blade or an articulated rigid blade with one or more torsion springs, for a wind turbine or a water turbine, the flexible blade being designed to passively control the pitch angle of the wind turbine or of the water turbine during operation, the method comprising the following steps: a) receiving the known geometric profile; b) determining a change in the optimal pitch angle, 0o opt rigid, as a function of the specific speed λ; c) determining the local behaviour of the flexible blade or of the articulated blade and local ratios relating to the aerodynamic loading and to the centrifugal force being exerted on the blade; d) determining local values of the bending modulus B of the flexible blade/the stiffness of the torsion spring and of the mass density p of the blade; and e) providing information relating to the selection of the material.

Claims38

Dependent claims

A method for designing a predefined wind turbine or water turbine flexible blade, the flexible blade having a known geometrical profile:

a known span as well as a thickness and a chord that are known and variable in the spanwise direction, a pitch angle at rest, the flexible blade being designed to be flexible at least according to the chord, for passively regulating the pitch angle of the wind turbine or water turbine in operation,
the method comprising the following steps:
a) receiving the known geometrical profile,
b) determining, for said geometrical profile applied to a reference rigid blade, a change of the optimum pitch angle of the rigid blade θ0 opt rigid as a function of the specific speed λ equal to the ratio between the speed considered at the end of the blade and the incident fluid speed, for a speed regime of the fluid flowing around the reference rigid blade,
c) determining the local behavior of the flexible blade, deforming under the effect, on the one hand, of the aerodynamic loading of the fluid circulating around flexible blade and, on the other hand, of the centrifugal force exerted on the flexible blade in rotation, and determining local ratios relating to the aerodynamic loading and to the centrifugal force exerted on the flexible blade,
d) determining local values of bending modulus B and mass density ρ, using the local ratios and the behavior of the flexible blade determined in step c) so that the change of a effective pitch angle θ0 eff of the flexible blade, conferred by the flexibility at least according to the chord of the flexible blade, as a function of the specific speed λ, corresponds to the change determined in the previous step b), and
e) restituting an information relating to the choice of the material, determined from the local values of bending modulus B and mass density ρ calculated in step d) and from the geometrical profile received in step a).

4 more elements

A method for designing a predefined wind turbine or water turbine rigid blade, the rigid blade having a known geometrical profile:

a known span as well as a thickness and a chord that are known and variable in the spanwise direction, a pitch angle at rest, the rigid blade being hinged around an arm of the wind turbine/water turbine, the rigid blade being able to perform a rotational movement around the arm according to its span, at least one torsion spring connecting the rigid blade with the arm whose stiffness K is chosen for passively regulating the pitch angle of the wind turbine or water turbine in operation, the method comprising the following steps:
a) receiving the known geometrical profile,
b) determining, for said geometrical profile applied to a reference rigid blade, a change of the optimum pitch angle of the rigid blade θ0 opt rigid as a function at least of the specific speed λ equal to the ratio between the speed considered at the end of the blade and the incident fluid speed, for a speed regime of the fluid flowing around the rigid blade,
c) determining the behavior of the hinged rigid blade with torsion spring, the hinged rigid blade moving under the effect of the aerodynamic loading of the fluid circulating around this rigid blade, of the elastic return force of the torsion spring and of the centrifugal force exerted on this rigid blade in rotation,
and determining local ratios relating to the aerodynamic loading, to the elastic return force and to the centrifugal force exerted on this hinged rigid blade,
d) determining the stiffness K of the torsion spring and local values of the mass density ρ of the hinged rigid blade, using the local ratios and the behavior of the rigid blade determined in step c) so that the change of an effective pitch angle θ0 eff of the rigid blade, conferred by the torsion of the spring of the rigid blade, as a function of the specific speed λ, corresponds to the change determined in the previous step b), and
e) restituting an information relating to the choice of the material of the hinged rigid blade, and the stiffness K of the torsion spring.

4 more elements

Dependencies are inferred from the claim text.