Method of optimizing the profile of a composite material blade for rotor wheel of a turbine engine, and a blade having a compensated tang

Patent metadata

Field	Value
Publication number	US-10539028-B2
Application number	US-201113884682-A
Country	US
Kind code	B2
Filing date	Nov 8, 2011
Priority date	Nov 10, 2010
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

A method optimizing a composite material blade profile for a rotor wheel of a turbine engine, and a blade including a tang compensated by the method. The method includes: compensating a blade airfoil by subdividing the airfoil into slices, and for each airfoil slice and a predetermined rotation speed of a disk of the wheel, calculating centrifugal force applied to the slice, calculating an aerodynamic force moment acting on a bottom section of the slice, and calculating shift values to be applied to a center of gravity of the slice to cancel the aerodynamic force moment; and compensating the blade tang by calculating centrifugal force applied to a blade portion situated beyond the airfoil neck, calculating an aerodynamic force moment acting on a bottom section of the blade tang, and calculating shift values to be applied to a center of gravity of the blade tang to cancel the aerodynamic force moment.

First claim

The invention claimed is:

1. A method of manufacturing a composite material blade having an optimized profile for a rotor wheel of a turbine engine, the blade including an airfoil including a plurality of blade sections stacked in a radial direction of the wheel, a root for mounting on a disk of the wheel and extended by a tang, and an inner platform situated between the tang and the airfoil, the root being connected to the tang by a neck, the method comprising:
entering values relating to a geometrical profile of the blade, to dimensions of the blade, and to a mass of the blade into calculation software;
optimizing the profile of the blade by shifting centers of gravity of various blade sections in tangential and longitudinal directions, said optimizing of the profile of the blade comprising:
compensating the blade airfoil, including subdividing the airfoil into slices, each slice defined between a bottom section and a top section, and for each airfoil slice and for a predetermined speed of rotation of the wheel disk, calculating centrifugal force to which the slice is subjected, calculating moment of aerodynamic force acting on the bottom section of the slice, and calculating shift values to be applied to a center of gravity of the slice in tangential and longitudinal directions to cancel a moment of aerodynamic force acting on the bottom section of the slice; and
compensating the blade tang, including calculating centrifugal force to which a portion of the blade situated above the neck is subjected, which portion is constituted by the airfoil, by the inner platform, and by the tang, calculating a moment of the aerodynamic force acting on a bottom section of the tang of the blade, and calculating shift values to be applied to a center of gravity of the blade tang along tangential and longitudinal directions to cancel a moment of aerodynamic force acting on the bottom section of the blade tang; and

manufacturing the blade having the optimized profile.

2. A method according to claim 1 , wherein the shift values to be applied to the centers of gravity of the airfoil slices and to the blade tang are smoothed over a full height of the blade.

3. A method according to claim 1 , wherein the centrifugal force F C to which each airfoil slice is subjected is given by formula:
F C =M T ×R COG ×ω 2

with M T being mass of the airfoil slice; R COG being distance between the axis of rotation of the disk and the center of gravity of the airfoil slice; and w being speed of rotation of the disk at the predetermined speed.

4. A method according to claim 1 , wherein shift values δ X , δ Y for application to the center of gravity of an airfoil slice are given by formulas:
δ X =M Y−faero /F C

δ Y =M X−faero /F C

with: M X−faero being a component of the moment of the aerodynamic force acting on the bottom section of the slice in the longitudinal direction; and M Y−faero being a component of the moment of the aerodynamic force acting on the bottom section of the slice in the tangential direction.

5. A method according to claim 1 , wherein shift values δ′ X , δ′ Y for application to the center of gravity of the blade tang are given by formulas:
δ′ X =M′ Y−faero /F′ C

δ′ Y =M′ X−faero /F′ C

with: M ′X−faero being a component of the moment of the aerodynamic force acting on the bottom section of the blade tang in the longitudinal direction; and M′ Y−faero being a component of the moment of the aerodynamic force acting on the bottom section of the blade tang in the tangential direction.

6. A method according to claim 1 , wherein the blade also includes an outer platform in a vicinity of the free end of the airfoil, and the compensating the tang applies to a portion of the blade including the airfoil, the inner platform, the tang, and the outer platform of the blade.

7. A method according to claim 1 , wherein, in the compensating the blade airfoil, the airfoil is subdivided into ten slices, each occupying 10% of total height of the airfoil.

8. A composite material blade for a rotor wheel of a turbine engine, the blade having an optimized profile and comprising:
an airfoil including a plurality of blade sections stacked in a radial direction of the wheel;
a root for mounting on a disk of the wheel and extended by a tang, the rotor wheel being centered on a longitudinal axis of the turbine engine; and
an inner platform situated between the tang and the airfoil;
the root being connected to the tang by a neck;
wherein the blade without the optimized profile has a geometrical profile for which the coordinates of a center of gravity of the blade tang are D X , D Y , and D Z and in an O, X, Y, Z orthogonal reference frame defined by the rotor wheel, the longitudinal axis X being parallel to the longitudinal axis of the turbine engine and O being centered on the longitudinal axis of the engine, the blade with the optimized profile has an optimized geometrical profile for which coordinates of a center of gravity of the blade tang are given by formulas:
D′ X =D X +δ′ X

D′ Y =D Y +δ′ Y

D′ Z =D Z

where:
δ′ X and δ′ Y are compensation values for the tang given by formulas:
δ′ X =M′ Y−faero /F′ C

δ′ Y =M′ X−faero /F′ C

with:
M′ X−faero being a component of the moment of the aerodynamic force acting on a bottom section of the blade tang in the longitudinal direction X; and
M′ Y−faero being a component of the moment of the aerodynamic force acting on the bottom section of the blade tang in the tangential direction Y.

Assignees

• Duval Sylvain Yves Jean
• Roussille Clement
• Schweitzer Alain
• Girard Patrick Joseph Marie
• Snecma
• Herakles

Inventors

• Duval Sylvain Yves Jean
• Roussille Clement
• Schweitzer Alain
• Girard Patrick Joseph Marie

Classifications

• F01D5/282 Primary

  Selecting composite materials, e.g. blades with reinforcing filaments · CPC title

• F05D2260/941

  particularly aimed at mechanical or thermal stress reduction · CPC title

• F01D5/141 Primary

  Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147) · CPC title

• G06F30/00

  Computer-aided design [CAD] · CPC title

• F01D5/148

  Blades with variable camber, e.g. by ejection of fluid · CPC title