Compound Cooling Flow Turbulator for Turbine Component
Multi-scale turbulation features, including first turbulators (46, 48) on a cooling surface (44), and smaller turbulators (52, 54, 58, 62) on the first turbulators. The first turbulators may be formed between larger turbulators (50). The first turbulators may be alternating ridges (46) and valleys (48). The smaller turbulators may be concave surface features such as dimples (62) and grooves (54), and/or convex surface features such as bumps (58) and smaller ridges (52). An embodiment with convex turbulators (52, 58) in the valleys (48) and concave turbulators (54, 62) on the ridges (46) increases the cooling surface area, reduces boundary layer separation, avoids coolant shadowing and stagnation, and reduces component mass.
This application is a continuation-in-part of U.S. patent application Ser. No. 12/536,869 (attorney docket 2009P10468US) filed on 6 Aug. 2009 and incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED DEVELOPMENTDevelopment for this invention was supported in part by Contract Number DE-FC26-05NT42644, awarded by the United States Department of Energy. Accordingly the United States Government may have certain rights in this invention.
FIELD OF THE INVENTIONThis invention relates to turbulators in cooling channels of turbine components, and particularly in gas turbine airfoils.
BACKGROUND OF THE INVENTIONStationary guide vanes and rotating turbine blades in gas turbines often have internal cooling channels. Cooling effectiveness is important in order to minimize thermal stress on these airfoils. Cooling efficiency is important in order to minimize the volume of air diverted from the compressor for cooling.
One cooling technique uses serpentine cooling channels with turbulators. An example is shown in U.S. Pat. No. 6,533,547. The present invention provides improved turbulators with features at multiple scales in combinations that increase surface area, increase boundary layer mixing, and control boundary layer separation.
The invention is explained in the following description in view of the drawings that show:
Herein, the terms “larger” and “smaller” refer to relative scales such that a smaller feature has less than ⅓ of the transverse sectional area of a respective “first” feature, and a larger feature has at least 3 times the sectional area of a respective first feature. For example, if a first ridge has a transverse sectional area of 1 cm2, then a respective smaller ridge has a transverse sectional area of less than ⅓ cm2. The term “transverse sectional area” of a bump or dimple is defined as the area of a projection of the bump or dimple onto a plane normal to the channel surface 44 at the apex of the bump or at the bottom of the dimple.
The term “convex turbulation feature” herein includes ridges 46, 50, 51, and 52, and bumps 58. For example
Each additional scale of turbulation features increases the convective area of the channel inner surface 44. For example, if a planar surface is modified with semi-cylindrical ridges separated by tangent semi-cylindrical valleys, the surface area is increased by a factor of about 1.57. If the surfaces of these ridges and valleys are then modified with smaller scale ridges, grooves, bumps, or dimples, the surface area is further increased. In the exemplary configuration of
Smaller features may be described herein as being on a top or side surface of a first feature. A “top surface” of a turbulator is a surface distal to the cooling surface to which the turbulator is attached, and is generally parallel to or aligned with the cooling surface. On a convex turbulator with a rectangular cross section, the top surface may be a planar surface 60, as shown in
Alternately forming smaller grooves in the valleys 48 may create some coolant stagnation in some embodiments and is not illustrated here. However, forming smaller convex features on first convex features, and/or forming smaller concave features in first concave features, reduces crowding of the smaller features, since they extend toward the outside of the sectional curvatures of the first features.
Other combinations of multi-scale turbulation features are possible. For example in
While various embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions may be made without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.
Claims
1. A turbine component with an interior cooling surface comprising:
- a first plurality of surface features separated by a first plurality of valleys, the first plurality of surface features configured to increase turbulence in a coolant flowing adjacent to the interior cooling surface;
- a second plurality of surface features separated by a second plurality of valleys, each of the second plurality of surface features smaller than each of the first plurality of surface features, the second plurality of surface features located between and non-parallel to the first plurality of surface features; and
- a third plurality of surface features, each smaller than each valley from second plurality of valleys;
- wherein: the first plurality of surface features comprise first ridges.
2. The turbine component of claim 1, wherein:
- the second plurality of surface features comprises grooves.
3. The turbine component of claim 1, wherein:
- the second plurality of surface features comprises second ridges.
4. The turbine component of claim 1, wherein:
- the second plurality of surface features comprises bumps.
5. The turbine component of claim 1, wherein:
- the second plurality of surface features comprises dimples.
6. The turbine component of claim 1, wherein:
- the second plurality of surface features are convex.
7. The turbine component of claim 1, wherein:
- the second plurality of surface features are concave.
8. The turbine component of claim 1, wherein:
- one or more of the second plurality of surface features is convex.
9. The turbine component of claim 1, wherein:
- one or more of the second plurality of surface features is concave.
10. The turbine component of claim 1, wherein:
- one or more of the second plurality of surface features comprises a gap.
11. The turbine component of claim 1, wherein:
- one or more of the second plurality of surface features is configured to increase a surface area of the interior cooling surface.
12. The turbine component of claim 1, wherein:
- one or more of the second plurality of surface features is configured to increase turbulence in a coolant flowing adjacent to the interior cooling surface.
13. The turbine component of claim 1, wherein:
- one or more of the second plurality of surface features is configured to decrease a mass of the turbine component.
14. The turbine component of claim 1, wherein:
- the third plurality of surface features comprises grooves.
15. The turbine component of claim 1, wherein:
- the third plurality of surface features comprises third ridges.
16. The turbine component of claim 1, wherein:
- the third plurality of surface features comprises bumps.
17. The turbine component of claim 1, wherein:
- the third plurality of surface features comprises dimples.
18. The turbine component of claim 1, wherein:
- the third plurality of surface features are convex.
19. The turbine component of claim 1, wherein:
- the third plurality of surface features are concave.
20. The turbine component of claim 1, wherein:
- one or more of the third plurality of surface features is convex.
21. The turbine component of claim 1, wherein:
- one or more of the third plurality of surface features is concave.
22. The turbine component of claim 1, wherein:
- one or more of the third plurality of surface features comprises a gap.
23. The turbine component of claim 1, wherein:
- one or more of the third plurality of surface features is configured to increase a surface area of the interior cooling surface.
24. The turbine component of claim 1, wherein:
- one or more of the third plurality of surface features is configured to increase turbulence in a coolant flowing adjacent to the interior cooling surface.
25. The turbine component of claim 1, wherein:
- one or more of the third plurality of surface features is configured to decrease a mass of the turbine component.
26. The turbine component of claim 1, wherein:
- the third plurality of surface features is located between and non-parallel to the second plurality of surface features.
27. The turbine component of claim 1, wherein:
- the second plurality of surface features have a sinusoidal geometry.
28. The turbine component of claim 1, wherein:
- the second plurality of surface features comprise alternating convex ridges and concave valleys.
29. The turbine component of claim 1, wherein:
- the second plurality of surface features are substantially perpendicular to the first plurality of surface features.
30. The turbine component of claim 1, wherein:
- each of the second plurality of surface features is elongated and defines a longitudinal axis that is oriented substantially parallel to a flow direction of the coolant.
Type: Application
Filed: Nov 18, 2014
Publication Date: Mar 19, 2015
Inventors: Ching-Pang Lee (Cincinnati, OH), Nan Jiang (Jupiter, FL), John J. Marra (Winter Springs, FL), Ronald J. Rudolf (Jensen Beach, FL)
Application Number: 14/546,153
International Classification: F01D 5/18 (20060101);