Method for modeling a non-streamlined propeller blade

1. A method for manufacturing a blade of a non-streamlined propeller, the method comprising:

modeling said blade, using a data processor or a piece of equipment, at least one portion of the blade having a tangential offset along a direction orthogonal to a longitudinal axis of said blade, said modeling comprising:

(a) parameterizing at least one Bezier curve representing a deformation of said blade characterizing the tangential offset, depending on a position along a section at a given height in the blade, the curve being defined by:

a. A first and second end control point (PCU1, PCUK) defining the extent of said section of the blade;

b. At least one intermediate control point (PCUi, i∈[[2,K−1]]) positioned between the end points (PCU1, PCUK),

the parameterization being performed according to at least one deformation parameter and said height of the section in the blade, as a function of which the abscissa of the intermediate control point (PCUi) and the ordinate of the second end point (PCUK) are expressed;

(b) determining optimized values of the deformation parameter(s);

(c) outputting to an interface of said piece of equipment the thereby determined values;

(d) manufacturing said blade according to the modeling of the at least one portion of the blade obtained by said modeling.

2. The method according to claim 1 , wherein the deformation parameters are a relative height at the onset of deformation (h 0 ) and a maximum offset (d max ) at the end of the blade, the at least one parameterized Bezier curve being associated with a relative height h of a section in the blade, h∈[h 0 , 1].

3. The method according to claim 2 , wherein the ordinate (y K ) of the second end control point (PCU K ) is given by

y

K

=

d

max

*

(

h

-

h

0

1

-

h

0

)

2

.

4. The method according to claim 2 , wherein the abscissa (x i ) of the at least one intermediate control point (PCU i ) is proportional to

x

rel

=

1

-

(

h

-

h

0

1

-

h

0

)

2

.

5. The method according to claim 1 , wherein K≥4, the i ith (i∈[[2, K−2]]) intermediate control points (PCU i ) being movable points for which the abscissa depends on the height of said section in the blade, the K−2 th intermediate control point (PCU K-1 ) being set.

6. The method according to claim 4 , in which the abscissa (x i ) of the K−3 movable intermediate control points (PCU i ) is given by

x

i

∈

〚

2

,

K

-

2

〛

=

x

K

-

1

*

i

-

1

K

-

3

*

x

rel

with (x K-1 ) the abscissa of the set intermediate control point (PCU K-1 ).

7. The method according to claim 6 , wherein x K-1 =0.75.

8. The method according to claim 5 , wherein K=7, so as to have four movable intermediate control points (PCU i ).

9. The method according to claim 1 , wherein the ordinate of the first end control point (PCU 1 ) and of each intermediate control point (PCU i ) is equal to zero.

10. The method according to claim 9 , wherein the derivative of the Bezier curve at the first end control point (PCU 1 ) is zero.

11. The method according to claim 1 , wherein a plurality of Bezier curves corresponding to sections at different heights in the blade is parameterized in said step (a).

12. The method according to claim 1 , wherein the optimized values determined in said step (b) are values of the deformation parameters for which the intensity of a marginal vortex generated by the blade is a minimum.

13. A non-streamlined propeller comprising a plurality of blades obtained via the method according to claim 1 .