FLUID-FLOW MACHINE - BLADE WITH HYBRID PROFILE CONFIGURATION

• US 20120148396A1
• Filed: 12/08/2011
• Published: 06/14/2012
• Est. Priority Date: 12/08/2010
• Status: Active Grant

• Current Assignee: Rolls-Royce Deutschland Limited & Company KG (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce Deutschland Limited & Company KG (Rolls-Royce Holdings Plc)
• Inventors: GUEMMER, Volker
• Granted Patent: US 9,394,794 B2
• Time in Patent Office: Days
• US Class Current: 415/208.2
• CPC Class Codes: F01D 5/145 Means for influencing boundary layers or secondary circulations for compressors F04D29/68
• CPC Class Codes: F01D 5/146 of blades with tandem configuration, split blades or slotted blades
• CPC Class Codes: F04D 29/324 Blades
• CPC Class Codes: F04D 29/384 characterised by form
• CPC Class Codes: F04D 29/544 Blade shapes
• CPC Class Codes: F04D 29/682 by fluid extraction
• CPC Class Codes: F04D 29/684 by fluid injection
• CPC Class Codes: F05D 2240/301 Cross-sectional characteristics
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A blade for use in a fluid-flow machine, where at least one of the meridional flow line profile sections MSLi and MSLo is provided at a distance of max. 35% of the main flow path width from the respective inner and outer main flow path boundaries. The blade has in at least parts of a central area a multi-profile configuration such that at least two partial profiles (7, 9, 10) arranged one behind the other in the flow direction are provided, of which each has substantially the shape of a blade profile, where a passage (8) is provided between each two partial profiles and is passed through by fluid from the blade pressure side to the blade suction side.

Claims

1. A blade of a rotor or stator row with hybrid profile configuration for use in a fluid-flow machine,

the blade being configured for positioning in a main flow path confined by an inner and an outer main flow path boundary and having a main flow path width W, where the blade is split in a direction of its blade height into an inner boundary area IRB (defined between the inner main flow path boundary HBi and a nearby inner meridional flow line profile section MSLi), an outer boundary area ARB (defined between the outer main flow path boundary HBo and a nearby outer meridional flow line profile section MSLo) and a central area ZB (defined between the inner meridional flow line profile section MSLi and the outer meridional flow line profile section MSLo),

wherein at least one of the meridional flow line profile sections MSLi and MSLo is provided at a distance of max. 35% of the main flow path width from its associated main flow path boundary,

wherein the blade has in at least parts of the central area a multi-profile configuration such that at least two partial profiles arranged one behind the other in the flow direction are provided, of which each has substantially a blade profile shape,

wherein at least one passage is provided between each of the two partial profiles and is passed through by fluid from the blade pressure side to the blade suction side,

wherein the at least one passage has, along the blade height, a variable passage width d,

wherein a local value of the at least one passage width d is measured by a smallest distance that can be determined by inscribing a circle between contours of the two adjacent partial profiles on the same radius,

wherein the passage width d along the blade height has a maximum value in at least one of the inner and outer boundary areas IRB and ARB,

wherein in at least one of the inner and outer boundary areas IRB and ARB, a changeover from the multi-profile configuration to a single-profile configuration is provided when viewing a blade profile section geometry in a direction of the main flow path boundary adjoining the respective boundary area (IRB or ARB) and the at least one passage ends at the point of changeover confined by a flank surface FF,

wherein a part of an edge of the flank surface FF is designed as a SSFFK edge on the blade suction side,

wherein a part of the edge of the flank surface FF is designed as a DSFFK edge on the blade pressure side and a distance greater than zero is provided between the DSFFK edge and the main flow path boundary,

wherein at least one of the boundary areas IRB and ARB is provided at a fixed blade end provided with a shroud or blade root.

2. The blade of claim 1, wherein at least one of the meridional flow line profile sections MSLi and MSLo is provided at a distance of max. 20% of the main flow path width from its associated main flow path boundary.

3. The blade of claim 2, wherein, when viewing the blade along its blade height the changeover from the multi-profile configuration to the single-profile configuration is such that a profile contour of the single profile encloses the partial profiles of the multi-profile arrangement and forms at least partially joint contour sections with the partial profiles of the multi-profile arrangement and that when viewing the blade along its blade height the changeover from the multi-profile configuration to the single-profile configuration is such that at least one of the trailing and leading edges of the partial profiles of the multi-profile arrangement projects beyond the profile contour of the single profile.

4. The blade of claim 3, wherein at least one of the flank surface edges SSFFK and DSFFK is provided substantially or exactly in a meridional flow line profile section.

5. The blade of claim 4, wherein at least one of the following applies:

the suction-side flank surface edge SSFFK is at least partially closer to the main flow path boundary of the respective boundary area (IRB or ARB) than the pressure-side flank surface edge DSFFK, resulting in a course of the flank surface FF inclined relative to at least one of the circumferential direction u or the meridional direction m and—

in a flow direction—

to the main flow path boundary;

or that the suction-side flank surface edge SSFFK is at least partially provided at the main flow path boundary at or upstream of a trailing edge of a partial profile and that thus a single profile configuration is provided in the respective boundary area (IRB or ARB) only in the meridional flow line profile section directly at the main flow path boundary.

6. The blade of claim 5, wherein at least one of the following applies:

at least one section of one of the flank surface edges DSFFK and SSFFK approaches in the flow direction a main flow path boundary and is thus inclined relative to meridional flow line profile sections of the blade;

or that a course of the pressure-side flank surface edge DSFFK, when viewed in the flow direction,

a) includes a first section, in which the DSFFK is substantially or exactly provided along a meridional flow line profile section, and

b) includes a second section adjoining the first one in the flow direction, in which the DSFFK is inclined relative to the meridional flow direction and thereby approaches the main flow path boundary adjoined by the boundary area IRB or ARB including the DSFFK.

7. The blade of claim 6, wherein the flank surface FF is substantially or precisely provided as part of a conical surface whose axis of symmetry is defined by an axis of the fluid-flow machine, such that a projection of the flank surface FF into the meridional plane x-r results in a projection line PL, having an S-shaped course.

8. The blade of claim 7, wherein at least one of the following applies:

a pressure-side flank surface edge DSFFK starts in the immediate vicinity of or directly at the leading edge of at least one of a partial profile or the blade;

or a suction-side flank surface edge SSFFK starts in the immediate vicinity of or directly at the leading edge of at least one of the partial profile or the blade.

9. The blade of claim 8, wherein:

the multi-profile configuration includes an arrangement with at least two partial profiles,

a meridional distance Am between a trailing edge of a partial profile and a leading edge of an adjacently arranged downstream partial profile is defined,

the meridional distance Am in at least one part of the main flow path width is provided with negative values and thus adjacent partial profiles overlap in the meridional flow direction and form a duct-like flow passage between them,

the overlap at least in a partial section of the blade increases towards the main flow path boundary of the respective blade end, and the trailing edge HKT1 of a front partial profile extends in the direction of the main flow path boundary increasingly far downstream of a leading edge VKT2 of a rear partial profile, and

at least one of the following;

a decreasing overlap is provided, starting from a point in the central area ZB of the blade and extending in a direction of at least one blade end up to the point of changeover from the multi-profile configuration to the single-profile configuration;

or the suction-side flank surface edge SSFFK is provided at the main flow path boundary such that the meridional flow line profile section of the blade includes a ledge in its suction-side course directly on the main flow path boundary at a point upstream of or directly at the trailing edge of at least one of the partial profile or the blade.

10. The blade of claim 9, wherein a distribution of the passage width d/dmin=fkt (w/W) in the central area ZB assumes a minimum value, and a maximum value of the passage width is greater than the minimum value of the passage width by at least a factor of 1.5, in accordance with dmax/dmin>

1.5.

11. The blade of claim 1, wherein, when viewing the blade along its blade height the changeover from the multi-profile configuration to the single-profile configuration is such that a profile contour of the single profile encloses the partial profiles of the multi-profile arrangement and forms at least partially joint contour sections with the partial profiles of the multi-profile arrangement and that when viewing the blade along its blade height the changeover from the multi-profile configuration to the single-profile configuration is such that at least one of the trailing and leading edges of the partial profiles of the multi-profile arrangement projects beyond the profile contour of the single profile.

12. The blade of claim 11, wherein at least one of the flank surface edges SSFFK and DSFFK is provided substantially or exactly in a meridional flow line profile section.

13. The blade of claim 12, wherein at least one of the following applies:

the suction-side flank surface edge SSFFK is at least partially closer to the main flow path boundary of the respective boundary area (IRB or ARB) than the pressure-side flank surface edge DSFFK, resulting in a course of the flank surface FF inclined relative to at least one of the circumferential direction u or the meridional direction m and—

in a flow direction—

to the main flow path boundary;

or that the suction-side flank surface edge SSFFK is at least partially provided at the main flow path boundary at or upstream of a trailing edge of a partial profile and that thus a single profile configuration is provided in the respective boundary area (IRB or ARB) only in the meridional flow line profile section directly at the main flow path boundary.

14. The blade of claim 13, wherein at least one of the following applies:

at least one section of one of the flank surface edges DSFFK and SSFFK approaches in the flow direction a main flow path boundary and is thus inclined relative to meridional flow line profile sections of the blade;

or that a course of the pressure-side flank surface edge DSFFK, when viewed in the flow direction,

a) includes a first section, in which the DSFFK is substantially or exactly provided along a meridional flow line profile section, and

b) includes a second section adjoining the first one in the flow direction, in which the DSFFK is inclined relative to the meridional flow direction and thereby approaches the main flow path boundary adjoined by the boundary area IRB or ARB including the DSFFK.

15. The blade of claim 14, wherein the flank surface FF is substantially or precisely provided as part of a conical surface whose axis of symmetry is defined by an axis of the fluid-flow machine, such that a projection of the flank surface FF into the meridional plane x-r results in a projection line PL, having an S-shaped course.

16. The blade of claim 15, wherein at least one of the following applies:

a pressure-side flank surface edge DSFFK starts in the immediate vicinity of or directly at the leading edge of at least one of a partial profile or the blade;

or a suction-side flank surface edge SSFFK starts in the immediate vicinity of or directly at the leading edge of at least one of the partial profile or the blade.

17. The blade of claim 16, wherein:

the multi-profile configuration includes an arrangement with at least two partial profiles,

a meridional distance Am between a trailing edge of a partial profile and a leading edge of an adjacently arranged downstream partial profile is defined,

the meridional distance Am in at least one part of the main flow path width is provided with negative values and thus adjacent partial profiles overlap in the meridional flow direction and form a duct-like flow passage between them,

the overlap at least in a partial section of the blade increases towards the main flow path boundary of the respective blade end, and the trailing edge HKT1 of a front partial profile extends in the direction of the main flow path boundary increasingly far downstream of a leading edge VKT2 of a rear partial profile, and

at least one of the following;

a decreasing overlap is provided, starting from a point in the central area ZB of the blade and extending in a direction of at least one blade end up to the point of changeover from the multi-profile configuration to the single-profile configuration;

or the suction-side flank surface edge SSFFK is provided at the main flow path boundary such that the meridional flow line profile section of the blade includes a ledge in its suction-side course directly on the main flow path boundary at a point upstream of or directly at the trailing edge of at least one of the partial profile or the blade.

18. The blade of claim 17, wherein a distribution of the passage width d/dmin=fkt (w/W) in the central area ZB assumes a minimum value, and a maximum value of the passage width is greater than the minimum value of the passage width by at least a factor of 1.5, in accordance with dmax/dmin>

1.5.