Engine airfoils and methods for reducing airfoil flutter

Patent metadata

Field	Value
Publication number	US-9879539-B2
Application number	US-201414546186-A
Country	US
Kind code	B2
Filing date	Nov 18, 2014
Priority date	Nov 18, 2014
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

A method is provided for designing an airfoil. The method includes considering a baseline airfoil having a first camber distribution and a first aerodynamic efficiency; reducing the first camber distribution to result in a reduced camber airfoil with a second camber distribution and a second aerodynamic efficiency such that the second aerodynamic efficiency is approximately equal to the first aerodynamic efficiency; and producing the airfoil with the second camber distribution.

First claim

What is claimed is:

1. A method for designing an airfoil, the method comprising the steps of:
considering a baseline airfoil having a first camber distribution and a first aerodynamic efficiency;
reducing the first camber distribution to result in a reduced camber airfoil with a second camber distribution and a second aerodynamic efficiency, wherein the second aerodynamic efficiency is approximately equal to the first aerodynamic efficiency; and
producing the airfoil with the second camber distribution,
wherein the reducing step includes reducing the first camber distribution in one or more areas within a range between approximately 25% to approximately 75% along a radial height and maintaining the first camber distribution outside of the range.

2. The method of claim 1 , wherein the baseline airfoil has a first chord length, and wherein the producing step further includes producing the airfoil with the first chord length.

3. The method of claim 2 , wherein the baseline airfoil has a first thickness distribution, and wherein the producing step further includes producing the airfoil with the first thickness distribution.

4. The method of claim 3 , wherein the baseline airfoil has a first leading edge angle and a first trailing edge angle, and wherein the producing step further includes producing the airfoil with the first leading edge angle and the first trailing edge angle.

5. The method of claim 1 , wherein the baseline airfoil has a leading edge and a trailing edge, and wherein the reducing step includes reducing the camber distribution while maintaining the leading edge and the trailing edge.

6. The method of claim 1 , wherein the baseline airfoil has a first twist to flex ratio, and wherein the reducing step includes reducing the twist to flex ratio.

7. The method of claim 6 , wherein the reducing step is repeated until the twist to flex ratio reaches a predetermined value.

8. The method of claim 6 , wherein the reducing step is repeated until the twist to flex ratio is minimized.

9. The method of claim 1 , wherein the reducing step includes reducing the first camber distribution in one or more areas within a range between approximately 25% to approximately 75% along a chord length and maintaining the first camber distribution outside of the range.

10. A method for designing an airfoil, the method comprising the steps of:
considering a baseline airfoil having a first camber distribution and a first aerodynamic efficiency;
reducing the first camber distribution to result in a reduced camber airfoil with a second camber distribution and a second aerodynamic efficiency, wherein the second aerodynamic efficiency is approximately equal to the first aerodynamic efficiency; and
producing the airfoil with the second camber distribution,
wherein the reducing step includes reducing the first camber distribution in one or more areas within a range between approximately 25% to approximately 75% along a chord length and maintaining the first camber distribution outside of the range.

11. The method of claim 10 , wherein the baseline airfoil has a first leading edge angle and a first trailing edge angle, and wherein the producing step further includes producing the airfoil with the first leading edge angle and the first trailing edge angle.

12. The method of claim 10 , wherein the baseline airfoil has a first twist to flex ratio, and wherein the reducing step includes reducing the twist to flex ratio.

13. The method of claim 12 , wherein the reducing step is repeated until the twist to flex ratio reaches a predetermined value.

14. The method of claim 12 , wherein the reducing step is repeated until the twist to flex ratio is minimized.

15. A method for designing an airfoil, the method comprising the steps of:
considering a baseline airfoil having a first camber distribution and a first aerodynamic efficiency;
reducing the first camber distribution to result in a reduced camber airfoil with a second camber distribution and a second aerodynamic efficiency, wherein the second aerodynamic efficiency is approximately equal to the first aerodynamic efficiency; and
producing the airfoil with the second camber distribution,
wherein the reducing step includes reducing the first camber distribution in one or more areas within a first range between approximately 25% to approximately 75% along a radial height and within a second range between approximately 25% to approximately 75% along a chord length.

16. The method of claim 15 , wherein the reducing step further includes maintaining the first camber distribution outside of the first range and the second range.

17. The method of claim 15 , wherein the baseline airfoil has a first twist to flex ratio, and wherein the reducing step includes reducing the twist to flex ratio.

18. The method of claim 17 , wherein the reducing step is repeated until the twist to flex ratio reaches a predetermined value.

19. The method of claim 17 , wherein the reducing step is repeated until the twist to flex ratio is minimized.

Assignees

• Honeywell Int Inc

Inventors

• Lentz Jeff

Classifications

• F05D2250/70

  Shape · CPC title

• F05D2220/36

  specially adapted for the fan of turbofan engines · CPC title

• F01D5/141 Primary

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

• F01D5/16

  for counteracting blade vibration · CPC title

• F04D29/324

  Blades · CPC title