Structures and Methods for Forcing Coupling of Flow Fields of Adjacent Bladed Elements of Turbomachines, and Turbomachines Incorporating the Same

• US 20140205458A1
• Filed: 01/23/2014
• Published: 07/24/2014
• Est. Priority Date: 01/23/2013
• Status: Active Grant

• Current Assignee: Concepts NREC, LLC
• Original Assignee: Concepts ETI Incorporated (Concepts NREC, LLC)
• Inventors: Japikse, David
• Granted Patent: US 8,926,276 B2
• Time in Patent Office: Days
• US Class Current: 416/179
• CPC Class Codes: B23P 15/006 turbine wheels
• CPC Class Codes: F01D 25/06 for preventing blade vibration means on blade-carrying members or blades F01D5/00
• CPC Class Codes: F01D 5/142 of the blades of successive rotor or stator blade-rows
• CPC Class Codes: F01D 5/145 Means for influencing boundary layers or secondary circulations for compressors F04D29/68
• CPC Class Codes: F01D 5/225 by shrouding
• CPC Class Codes: F01D 9/041 using blades F01D5/148 takes precedence
• CPC Class Codes: F01D 9/045 for radial flow machines or engines
• CPC Class Codes: F04D 1/00 Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps adapted for pumping specific fluids F04D7/00; priming or boosting F04D9/00
• CPC Class Codes: F04D 17/10 for compressing or evacuating
• CPC Class Codes: F04D 29/162 of a centrifugal flow wheel
• CPC Class Codes: F04D 29/167 of a centrifugal flow wheel
• CPC Class Codes: F04D 29/245 for special effects
• CPC Class Codes: F04D 29/281 for fans or blowers
• CPC Class Codes: F04D 29/284 for compressors
• CPC Class Codes: F04D 29/324 Blades
• CPC Class Codes: F04D 29/325 for axial flow fans blade mountings F04D29/34, blades F04D29/38
• CPC Class Codes: F04D 29/384 characterised by form
• CPC Class Codes: F04D 29/444 Bladed diffusers
• CPC Class Codes: F04D 29/448 bladed diffusers
• CPC Class Codes: F04D 29/542 Bladed diffusers fixing blades to stators F01D9/042
• CPC Class Codes: F04D 29/544 : Blade shapes
• CPC Class Codes: F04D 29/666 : by means of rotor construction or layout, e.g. unequal distribution of blades or vanes
• CPC Class Codes: F04D 29/685 : Inducing localised fluid recirculation in the stator-rotor interface
• CPC Class Codes: F05D 2240/121 : related to the leading edge of a stator vane
• CPC Class Codes: F05D 2240/126 : Baffles or ribs
• CPC Class Codes: F05D 2240/303 : related to the leading edge of a rotor blade
• CPC Class Codes: F05D 2250/52 : Outlet
• CPC Class Codes: Y10T 29/49229 : Prime mover or fluid pump making

Abstract

Turbomachines having close-coupling flow guides (CCFGs) that are designed and configured to closely-couple flow fields of adjacent bladed elements. In some embodiments, the CCFGs may be located in regions extending between the adjacent bladed elements, described herein as coupling avoidance zones, where conventional turbomachine design would suggest no structure should be added. In yet other embodiments, CCFGs are located upstream and/or downstream of rows of blades coupled to the bladed elements, including overlapping one of more of the rows of blades, to improve flow coupling and machine performance. Methods of designing turbomachines to incorporate CCFGs are also provided.

Claims

1. A turbomachine, comprising:

a primary flow path;

a first bladed element having a first blade region containing a plurality of first blades in said primary flow path;

a second bladed element having a second blade region containing at least one second blade in said primary flow path, wherein said second blade region is located adjacent to and downstream from said first blade region; and

a close-coupling flow guide (CCFG) that is designed and configured to, during use, couple a primary flow field of said first bladed element within said primary flow path with a primary flow field of said second bladed element within said primary flow path to thereby increase at least one of a work input coefficient and relative impeller diffusion.

2. A turbomachine according to claim 1, further comprising a coupling avoidance zone extending between said first blade region and said second blade region, and wherein said CCFG is located in said coupling avoidance zone.

3. A turbomachine according to claim 1, wherein said second bladed element comprises a plurality of second blades arranged and configured into a low solidity blade row.

4. A turbomachine according to claim 3, wherein said second bladed element further comprises a plurality of third blades arranged and configured into a tandem blade row positioned downstream of said low solidity blade row, said tandem blade row having a lower blade count than said low solidity blade row.

5. A turbomachine according to claim 3, wherein said low solidity blade row comprises a plurality of flat plates.

6. A turbomachine according to claim 1, wherein said first bladed element comprises a centrifugal impeller and said second bladed element comprises a diffuser.

7. A turbomachine according to claim 1, wherein said CCFG comprises a contoured surface.

8. A turbomachine according to claim 7, wherein said contoured surface has a leg overlapping said first blade region.

9. A turbomachine according to claim 8, wherein a portion of said contoured surface is located in said second blade region.

10. A turbomachine according to claim 7, wherein said contoured surface is asymmetric.

11. A turbomachine according to claim 7, wherein said contoured surface includes a twisted surface.

12. A turbomachine according to claim 1, wherein said CCFG comprises a rib.

13. A turbomachine according to claim 12, wherein a first portion of said rib is located in said first blade region and a second portion of said rib is located in said second blade region.

14. A turbomachine according to claim 12, wherein said CCFG further comprises a second rib and a trough, said trough located between said rib and said second rib.

21. A turbomachine according to claim 1, wherein said first bladed element has a rotational axis and each of said plurality of first blades has a trailing edge located at a radius, r₂, from said rotational axis, said CCFG having a leading edge located at a radius, r_c, from said rotational axis, and wherein r_c/r₂ is less than about 1.08.

22. A turbomachine according to claim 21, wherein r_c/r₂ is equal to or less than about 0.

23. A turbomachine according to claim 1, wherein said turbomachine is an axial flow machine, said plurality of first blades each having a chord length, C, and a trailing edge, and wherein said CCFG has a leading edge, and wherein a distance between said leading edge and said trailing edge is less than about C/4.

15. A turbomachine, comprising:

a primary flow path;

a first blade row positioned adjacent to a second blade row, said second blade row located downstream of said first blade row in said primary flow path of said turbomachine; and

a close-coupling flow guide (CCFG) located proximate to at least one of said first blade row and said second blade row, said CCFG being designed and configured to couple a primary flow field of said first blade row within said primary flow path with a primary flow field of said second blade row within said primary flow path so as to provide a non-negligible increase in at least one of a work input coefficient and relative impeller diffusion.

16. A turbomachine according to claim 15, wherein said first blade row includes a first blade region and said second blade row includes a second blade region, and wherein said CCFG overlaps one of said first blade region and said second blade region.

17. A turbomachine according to claim 16, wherein said turbomachine includes a coupling avoidance zone extending between said first blade region and said second blade region, and wherein a portion of said CCFG is located in said coupling avoidance zone.

18. A turbomachine according to claim 15, further comprising a hub surface and shroud surface, and wherein said CCFG is formed in at least one of said hub surface and said shroud surface.

19. A turbomachine according to claim 18, wherein said CCFG is a trough formed in said shroud surface.

20. A turbomachine according to claim 19, wherein said trough overlaps both said first blade row and said second blade row.

24. A turbomachine according to claim 15, wherein said first blade row has a plurality of first blades and a rotational axis and each of said plurality of first blades has a trailing edge located at a radius, r₂, from said rotational axis, said CCFG having a leading edge located at a radius, r_c, from said rotational axis, and wherein r_c/r₂ is less than about 1.08.

25. A turbomachine according to claim 24, wherein r_c/r₂ is equal to or less than about 0.

26. A turbomachine according to claim 15, wherein said turbomachine is an axial flow machine, said first blade row including a plurality of first blades each having a chord length, C, and a trailing edge, and wherein said CCFG includes a leading edge, and wherein a distance between said leading edge and said trailing edge is less than about C/4.