Assembly for a fluid flow machine

Abstract

A structural assembly for a fluid-flow machine includes a main flow path boundary a row of relatively rotating blades with a gap existing between the blade ends and the main flow path boundary. A secondary flow duct is connected to the main flow path via two openings. A structural assembly has at least one support component and at least one insertion component. A structure extending in the circumferential direction and receiving or holding at least one insertion component along the circumference is provided in the support component. Each insertion component forms with at least some of its faces at least part of the main flow path boundary. Each secondary flow duct is jointly limited along at least part of its course by faces of at least two components of the structural assembly.

Claims

1. A structural assembly for a turbofan engine comprising: a main flow path boundary confining a main flow path of a fluid-flow machine, where at least one row of blades each with one blade end is arranged in the main flow path, where a gap exists between the blade ends of the at least one row of blades and the main flow path boundary, and where there is a rotating relative movement between the blades of a blade row and the main flow path boundary, and at least one secondary flow duct, having in the main flow path boundary, two openings, one opening each at ends spaced apart in a flow direction, such that the at least one secondary flow duct is connected to the main flow path via the two openings, wherein: the structural assembly has at least one support component and a separate at least one insertion component, the at least one support component includes a structure extending in a circumferential direction and receiving or holding the at least one insertion component along a circumference thereof, the structure extending in the circumferential direction is at least one chosen from a recess, a projection and a ridge, a face of the at least one insertion component forms a first part of the main flow path boundary, and the at least one secondary flow duct is jointly limited along at least part of a course thereof by faces of the at least one support component and the at least one insertion component, a face of the at least one support component forms a second part of the main flow path boundary; wherein the at least one support component is at least one chosen from an annular casing and a half-shell casing of the turbofan engine and encloses at least one further component of the structural assembly from outside the at least one further component.

2. The assembly in accordance with claim 1, wherein the structural assembly includes at least one auxiliary component with a face limiting the at least one secondary flow duct along at least part of its course.

3. The assembly in accordance with claim 1, wherein at least one auxiliary component is arranged in an axial direction in front of or behind the at least one insertion component and forms together with a further face of the at least one insertion component a section of the at least one secondary flow duct.

4. The assembly in accordance with claim 1, wherein the at least one support component is annular or semi-annular on a hub of the turbofan engine and braces at least one further component of the structural assembly from inside the at least one further component.

5. The assembly in accordance with claim 2, wherein at least one chosen from the at least one insertion component and the at least one auxiliary component of the assembly is a complete ring or a ring sector.

6. The assembly in accordance with claim 1, wherein both the at least one support component and the at least one insertion component are annular casings.

7. The assembly in accordance with claim 1, wherein the at least one secondary flow duct is provided predominantly in the at least one insertion component and a further face of the at least one support component completes the at least one secondary flow duct.

8. The assembly in accordance with claim 7, wherein the further face of the at least one support component completing the at least one secondary flow duct is at least one chosen from part of a plane, a cone, a circular cylinder and a cylinder such that sections of the at least one secondary flow duct in the at least one insertion component that are still open are closed flush.

9. The assembly in accordance with claim 1, wherein the at least one secondary flow duct is provided predominantly in the at least one support component and a further face of the at least one insertion component completes the at least one secondary flow duct.

10. The assembly in accordance with claim 9, wherein the further face of the at least one insertion component completing the at least one secondary flow duct is at least one chosen from part of a plane, a cone, a circular cylinder and a cylinder such that sections of the at least one secondary flow duct in the at least one support component that are still open are closed flush.

11. The assembly in accordance with claim 1, wherein a side of the at least one insertion component facing away from the main flow path is in a meridional view surrounded predominantly by the at least one support component.

12. The assembly in accordance with claim 1, wherein the at least one insertion component includes a shape and surface finish permitting insertion into the at least one support component in an axial direction of the turbofan engine.

13. The assembly in accordance with claim 1, wherein the at least one support component and the at least one insertion component are connected by a common flange.

14. The assembly in accordance with claim 1, wherein wetted surfaces of the at least one secondary flow duct are split between the at least one support component and the at least one insertion component such that a central section of the at least one secondary flow duct, which when seen in a meridional view, runs substantially along a direction of the main flow path boundary, is provided in the at least one support component and is covered by a surface of the at least one insertion component, while at least one section of the at least one secondary flow duct provided in an area of the two openings on the main flow path boundary includes all wetted faces completely inside the at least one insertion component.

15. The assembly in accordance with claim 1, and further comprising a replaceable plug that passes through at least one chosen from the at least one support component and the at least one insertion component from a side facing away from the main flow path, where the replaceable plug contains a section of the at least one secondary flow duct such to connect to a remaining section of the at least one secondary flow duct not extending inside the replaceable plug.

16. The assembly in accordance with claim 15, wherein a top face of the replaceable plug forms part of the main flow path boundary and the top face includes one of the two openings of the at least one secondary flow duct.

17. The assembly in accordance with claim 2, wherein a central section of the at least one secondary flow duct, which when seen in a meridional view runs substantially along a direction of the main flow path boundary, is provided in at least one chosen from the at least one support component and the at least one insertion component, and at least one further section of the at least one secondary flow duct, which is formed by a combination of faces of the at least one insertion component and the at least one auxiliary component, is provided in an area of the two openings on the main flow path boundary.

18. The assembly in accordance with claim 2, wherein the at least one auxiliary component can be pushed in an axial direction together with the at least one insertion component into the at least one support component.

19. The assembly in accordance with claim 1, wherein, when viewing a section of the at least one secondary flow duct in an area of the two openings on the main flow path boundary, one line with continuously convex curvature and one line with continuously concave curvature exist along the inner contour of the at least one secondary flow duct, the lines being substantially opposite each other inside a section of the at least one secondary flow duct.

20. A fluid-flow machine including an assembly in accordance with claim 1.

21. The assembly in accordance with claim 1, wherein the at least one support component and the at least one insertion component form an entirety of the at least one secondary flow duct.

22. A structural assembly for a turbofan engine comprising: a main flow path boundary confining a main flow path of a fluid-flow machine, where at least one row of blades each with one blade end is arranged in the main flow path, where a gap exists between the blade ends of the at least one row of blades and the main flow path boundary, and where there is a rotating relative movement between the blades of a blade row and the main flow path boundary, and at least one secondary flow duct, having in the main flow path boundary, two openings, one opening each at ends spaced apart in a flow direction, such that the at least one secondary flow duct is connected to the main flow path via the two openings, wherein: the structural assembly has at least one support component and a separate at least one insertion component, the at least one support component includes a structure extending in a circumferential direction and receiving or holding the at least one insertion component along a circumference thereof, the structure extending in the circumferential direction is at least one chosen from a recess, a projection and a ridge, a face of the at least one insertion component forms a first part of the main flow path boundary, and the at least one secondary flow duct is jointly limited along at least part of a course thereof by faces of the at least one support component and the at least one insertion component, a face of the at least one support component forms a second part of the main flow path boundary; wherein the at least one secondary flow duct is provided predominantly in the at least one insertion component and a further face of the at least one support component completes the at least one secondary flow duct.

23. The assembly in accordance with claim 22, wherein the further face of the at least one support component completing the at least one secondary flow duct is at least one chosen from part of a plane, a cone, a circular cylinder and a cylinder such that sections of the at least one secondary flow duct in the at least one insertion component that are still open are closed flush.

24. The assembly in accordance with claim 22, and further comprising a replaceable plug that passes through at least one chosen from the at least one support component and the at least one insertion component from a side facing away from the main flow path, where the replaceable plug contains a section of the at least one secondary flow duct such to connect to a remaining section of the at least one secondary flow duct not extending inside the replaceable plug.

25. The assembly in accordance with claim 24, wherein a top face of the replaceable plug forms part of the main flow path boundary and the top face includes one of the two openings of the at least one secondary flow duct.

26. A structural assembly for a turbofan engine comprising: a main flow path boundary confining a main flow path of a fluid-flow machine, where at least one row of blades each with one blade end is arranged in the main flow path, where a gap exists between the blade ends of the at least one row of blades and the main flow path boundary, and where there is a rotating relative movement between the blades of a blade row and the main flow path boundary, and at least one secondary flow duct, having in the main flow path boundary, two openings, one opening each at ends spaced apart in a flow direction, such that the at least one secondary flow duct is connected to the main flow path via the two openings, wherein: the structural assembly has at least one support component and a separate at least one insertion component, the at least one support component includes a structure extending in a circumferential direction and receiving or holding the at least one insertion component along a circumference thereof, the structure extending in the circumferential direction is at least one chosen from a recess, a projection and a ridge, a face of the at least one insertion component forms a first part of the main flow path boundary, and the at least one secondary flow duct is jointly limited along at least part of a course thereof by faces of the at least one support component and the at least one insertion component, a face of the at least one support component forms a second part of the main flow path boundary; wherein the at least one support component and the at least one insertion component are connected by a common flange.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention is described in the following with reference to the figures of the accompanying drawing, showing several exemplary embodiments.

(2) FIG. 1 shows a rotor casing with an integrated nozzle for injecting fluid into a running gap in accordance with the state of the art.

(3) FIG. 2A shows, in meridional sectional view, an exemplary embodiment of a rotor casing of a fluid-flow machine having a secondary flow duct.

(4) FIG. 2B shows, in a three-dimensional view, an exemplary embodiment of a rotor casing of a fluid-flow machine having a secondary flow duct.

(5) FIG. 3A shows a first exemplary embodiment of a structural assembly for a fluid-flow machine forming a secondary flow duct.

(6) FIG. 3B shows a second exemplary embodiment of a structural assembly for a fluid-flow machine forming a secondary flow duct.

(7) FIG. 3C shows a third exemplary embodiment of a structural assembly for a fluid-flow machine forming a secondary flow duct.

(8) FIG. 3D shows a fourth exemplary embodiment of a structural assembly for a fluid-flow machine forming a secondary flow duct.

(9) FIG. 3E shows a fifth exemplary embodiment of a structural assembly for a fluid-flow machine forming a secondary flow duct.

(10) FIG. 3F shows, in perspective view, some of the support components of the exemplary embodiment of FIG. 3E.

DETAILED DESCRIPTION

(11) The teachings in accordance with the state of the art for injection of fluid from a fluid supply chamber into a flow duct by means of a nozzle system were described at the outset on the basis of FIG. 1.

(12) FIG. 2A shows an arrangement of a blade row 3 with free end and running gap 5 in the meridional plane established by the axial direction x and the radial direction r. The running gap 5 separates the blade tip from a component 2 associated with the main flow path on the hub or casing of the fluid-flow machine. The component 2 forms here a main flow path boundary 4 towards the main flow path.

(13) There is a rotating relative movement between the blade tip and the component 2 associated with the main flow path. The illustration thus applies equally for the following arrangements:

(14) 1) rotating blade on stationary casing,

(15) 2) stationary blade on rotating hub,

(16) 3) stationary blade on rotating casing, and

(17) 4) rotating blade on stationary hub.

(18) The main flow direction in the main flow path is indicated by an arrow A. Further blade rows can be located upstream and/or downstream of the blade row 3 with running gap. Inside the component 2 associated with the main flow path, a row of secondary flow ducts 1 distributed over the circumference is provided in the area of the running gap 5, said ducts having an opening at each of their ends (supply opening and discharge opening).

(19) The openings of the secondary flow ducts are located on the main flow path boundary 4. FIG. 2A shows the outline or projection of a single secondary flow duct 1 in the meridional plane (x-r). Viewed spatially, each duct 1 has a three-dimensional and spatially winding course, shown by way of example in FIG. 2B.

(20) It is pointed out that the cross-sectional shape of the secondary flow ducts 1 in FIG. 2B is illustrated as rectangular only by way of example. The cross-section of the secondary flow ducts 1 in other design variants can for example be designed without corners, in particular circular or elliptical.

(21) FIG. 3A shows a structural assembly in accordance with the present invention in the area of a blade row with running gap in the meridional view (x-r). The main flow direction is indicated by an arrow A. The blade row is no longer shown here for the sake of a simpler illustration.

(22) In the structural assembly, at least one secondary flow duct 1 is provided which has two openings 111, 112 in the main flow path boundary 4 and is connected via these openings to the main flow path. It is pointed out here that in the exemplary embodiment of FIG. 3A the secondary flow duct 1 is designed as a one-way path, having one opening through which fluid flows out of the main flow duct into the secondary flow duct 1 and a second opening through which fluid exits the secondary flow duct 1. Through which of the openings 111, 112 fluid flows in, and through which of the openings 111, 112 fluid flows out, depends here on the precise positioning of the openings 111, 112 relative to the blades of the blade row 3 (cf. FIG. 2B).

(23) In alternative embodiments, it can be provided that at least one of the secondary flow ducts is formed by an arrangement in which a single duct splits along its course into at least two part-ducts and thereby forms a type of Y-configuration. In this case, an inflow opening and several outflow openings associated with the secondary flow duct are provided. According to a further alternative embodiment, it can be provided that at least one of the secondary flow ducts is formed by an arrangement in which at least two ducts converge into one duct, with several inflow openings and one outflow opening then being associated with the secondary flow duct.

(24) According to FIG. 3A, the secondary flow duct 1 is achieved using two components connected to one another, a support component 21 and an insertion component 22.

(25) The support component 21 is used for structural implementation in the area of the inner or outer main flow path boundary and can be part of the outward casing or of the inward hub of the fluid-flow machine. It can be provided that it forms with some of its faces part of the main flow path boundary 4. In the exemplary embodiment shown, the support component 21 represents a part of the outward casing of the fluid-flow machine. In principle, the support component 21 can in particular be a part of the fluid-flow machine design in the following areas: part of a single-shell or multi-shell casing of blade rows or stages with fixed blade geometry, part of a single-shell or multi-shell casing of blade rows or stages with variable blade geometry, part of rotor drums, rotor disks or blisk modules, part of inner shroud assemblies in the hub area of stator vanes.

(26) In the exemplary embodiment of FIG. 3A, the support component is designed as an annular casing of a fluid-flow machine or as a half-shell casing of a fluid-flow machine. With an appropriate arrangement in the hub area, it is for example designed annular on the hub of a fluid-flow machine or semi-annular on the hub of a fluid-flow machine.

(27) The support component 21 has a concave structure in the circumferential direction, which in the exemplary embodiment under consideration is designed as a recess and forms an outer face 210. The insertion component 22 having a convex shape is inserted into the recess along the circumference of the support component 21. It is provided here that the insertion component 22 forms with some of its faces part of the main flow path boundary 4.

(28) The secondary flow duct 1 is limited along its course on the one hand by faces of the support component 21 and on the other hand by faces of the insertion component 22, which together, i.e. in the assembled state, completely surround the secondary flow duct 1. In the exemplary embodiment shown of FIG. 3A, the insertion component 22 forms recesses in the shape of ducts 221 which are for example designed as grooves or the like on the outside of the insertion component 22. These ducts 221 are closed by the outer face 210 of the support component 21, so that overall completely closed secondary flow ducts 1 are created. The secondary flow ducts 1 are only opened via the openings 111, 112 to the main flow duct.

(29) The faces of the secondary flow ducts 1 wetted by flowing fluid are thus jointly formed by faces of different components of the structural assembly, in the exemplary embodiment of FIG. 3A by faces of the support component 21 and by faces of the insertion component 22. The insertion component 22 is here completely inserted into a recess of the support component 21.

(30) FIG. 3B shows a further exemplary embodiment of a structural assembly in the area of a blade row with running gap in the meridional view (x-r). The exemplary embodiment of FIG. 3B differs from the exemplary embodiment of FIG. 2A in that the grooves or ducts forming a secondary flow duct 1 are provided not in the insertion component 22, but in the support component 21. Accordingly, the support component includes grooves or ducts 211 which structure the outer face of the support component 21 in the area under consideration. An appropriate structuring of the support component 21 for the provision of grooves or ducts 211 can be achieved for example by milling or similar methods. The grooves or ducts 211 are closed by a substantially closed outer face 220 of the convex insertion component 22.

(31) While external grooves or the like for forming the secondary flow ducts 1 are provided in the insertion component 22 in FIG. 3A, they are provided in the support component 21 in FIG. 3B. In all other respects the exemplary embodiments of FIGS. 3A and 3B match one another.

(32) FIG. 3C shows a further exemplary embodiment of a structural assembly in the area of a blade row with running gap in the meridional view (x-r). In the exemplary embodiment of FIG. 3C, the insertion component 22 and the support component 21 form two annular or partially annular casings which are slid one above the other in the axial direction and adjoin one another in the radial direction when in the assembled state, with the insertion component 22 being surrounded on its side not facing the main flow path by the support component 21. This design variant has the advantage that the insertion component 22 is relatively easy to assemble in that it is slid in the axial direction of the fluid-flow machine into the support component 21.

(33) A flange section 215 of the support component 21, on which a flange section 225 of the insertion component 22 is positioned and fastened, for example, is used here for axial positioning. It is in turn provided that the insertion component 22 forms with some of its outer faces part of the main flow path boundary 4.

(34) The secondary flow duct 1 includes three sections: a central section 11, which as in the exemplary embodiment in FIG. 3B is formed by grooves or ducts 211 in the support component 21, and two sections 12, 13, which discharge into the openings 111, 112 respectively of the secondary flow duct 1 to the main flow path and which are designed as passages or openings 222, 223 in the insertion component 22.

(35) In this exemplary embodiment, the secondary flow duct 1 is therefore limited only along a part of its course, i.e. in its central section 11, jointly by faces of two components of the structural assembly, i.e. by faces 211 of the support component 21 and by the face 220 of the insertion component 22. The other sections 12, 13 of the secondary flow duct 1 are provided solely inside the insertion component 22.

(36) In the exemplary embodiment of FIG. 3C, the situation is therefore such that a split of the wetted surfaces of the secondary flow duct 1 between the support component 21 and the insertion component 22 is selected in a way that the central section 11 of the secondary flow duct 1, which when seen in the meridional view (x-r) runs substantially along the direction of the main flow path boundary, is provided in the support component 21 and is covered with a surface 220 of the insertion component 22, while the sections of the secondary flow duct 1 in the area of the openings 111, 112 on the main flow path boundary 4 are completely provided by all the wetted faces in the insertion component 22.

(37) FIG. 3D shows a further exemplary embodiment of a structural assembly in the area of a blade row with running gap in the meridional view (x-r). The structural assembly includes in turn a support component 21 and an insertion component 22, with the support component 21 being designed as an annular projection onto which the insertion component 22 is fitted in the axial direction, i.e. against the flow direction. The insertion component 22 here adjoins the support component 21 in the radial direction on the inside and on the outside.

(38) The structural assembly furthermore includes a replaceable plug 6 which passes through at least one of the two componentssupport component 21 and insertion component 22from the side facing away from the main flow path. In the present exemplary embodiment, both the support component 21 and the insertion component 22 are passed through by the plug 6 in the radial direction. It is furthermore provided that the replaceable plug 6 contains a section 12 of the secondary flow duct 1, such that it connects to a section 11 of the secondary flow duct 1 not running inside the plug 6, with the top face of the replaceable plug 6 forming part of the main flow path boundary 4 and one of the openings 111 of the secondary flow duct 1 being provided in the top face.

(39) The secondary flow duct 1 thus includes two sections 11, 12, where one section 11 is jointly limited by faces of two components of the structural assembly, i.e. the support component 21 and the insertion component 22, and where a further section 22 is provided completely inside the plug 6.

(40) The plug 6 is preferably designed non-elastic. It is for example bolted into the support component 21 and/or the insertion component 22.

(41) The design variant of FIG. 3D has the advantage that the reverse flow mechanism provided by the secondary flow duct 1 can be interrupted or switched on and off by replacing the plug 6. This also permits, in the case of wear in the area 12 of the secondary flow duct 1, renewal of this area 12 by replacing the plug 6.

(42) FIG. 3E shows a further exemplary embodiment of a structural assembly in the area of a blade row with running gap in the meridional view (x-r). Initially, the exemplary embodiment of FIG. 3E is similar to the exemplary embodiment of FIG. 3A to the extent that a central section 11 of the secondary flow duct 1 is provided which is formed by ducts or external grooves 221 in an insertion component 22 which is inserted into a recess of a support component 21, where the outer face of the support component closes said ducts or external grooves 221, respectively. In the central section 11, the secondary flow duct 1 is thus formed by faces of two components of the structural assembly, i.e. by faces of the support component 21 and by faces of the insertion component 22.

(43) Unlike in the exemplary embodiment of FIG. 3A, the secondary flow duct 1 includes two further sections 12, 13 in which the secondary flow duct 1 is likewise limited by faces of two components of the structural assembly, with however two additional components, i.e. two auxiliary components 71, 72, being provided which are arranged in the axial direction in front of and behind the insertion component 22 for limitation. The insertion component 22 and the two auxiliary components 71, 72 form to that extent a structural sub-assembly which is inserted into a recess extending in the circumferential direction inside the support component 21, for example in the axial direction.

(44) It can be provided as shown that the sections 12, 13 formed by faces of the insertion component 22 and of an auxiliary component 71, 72, and each discharging into one of the openings 111, 112 of the secondary flow duct 1, have a heavily curved course. Here the auxiliary components 71, 72 have in the exemplary embodiment shown, however not necessarily, a continuously concave curvature 113 and the corresponding faces of the insertion component 22 have a continuously convex curvature 114, for achieving the inner contour of the secondary flow duct 1 in the area of the sections 12, 13, i.e. in the area close to the opening. The corresponding concave and convex faces 113, 114 are substantially opposite each other.

(45) It is pointed out that instead of two auxiliary components, as shown in FIG. 3E, it is also possible to provide only one auxiliary component or a larger number of auxiliary components in alternative exemplary embodiments.

(46) FIG. 3E thus shows an exemplary embodiment in which the outer contours of the secondary flow duct 1 in the area close to the opening are provided by the insertion component 22 and by auxiliary components 71, 72, which are also part of the structural assembly.

(47) FIG. 3F shows in a perspective view the one auxiliary component 72 and the insertion component 22 of FIG. 3E, without the further components 21, 71 of FIG. 3E being shown too. The circumferential direction u is also shown, and it can be discerned that the insertion component 22 like the auxiliary component 72 (and of course also the support component, not shown) extend in the circumferential direction, either over part of the circumference of the main flow path boundary or over the entire circumference of the main flow path boundary, where the structures repeat themselves to form a secondary flow duct 1 along the circumference.

(48) FIG. 3F shows the recesses 221 in the insertion component 22, which form some of the faces of the secondary flow duct 1. Also, the faces with continuously concave curvature 113 and with continuously convex curvature 114 on the auxiliary component 72 and on the insertion component 22 can be discerned.

(49) The present invention, in its design, is not restricted to the exemplary embodiments presented above, which are only to be understood as examples. The shape and the embodiment of the secondary flow ducts and of the components constituting them (support component, insertion component and auxiliary component) can for example be designed in a different manner than that shown.