EP2927503A1 - Gas turbine compressor, aircraft engine and design method - Google Patents

Abstract

The present invention relates to a gas turbine compressor with at least one blade tip (10) and a radially opposite flow channel wall (20), in which a circumferential groove (31-33) is arranged, in which at least one web (40) is arranged, which is a radial A cutback (44), wherein an upstream beginning (41) of the cutback axially downstream of an upstream groove edge (21) between said groove edge and an upstream leading edge (11) of the blade tip and a downstream end (42) of the cutback in a blade tip closer half (21). 34) of a radial height (35) of the circumferential groove is arranged.

Description

The present invention relates to a gas turbine compressor and an aircraft engine with such a gas turbine compressor and a method for designing such a gas turbine compressor.

From the US 2010/0014956 A1 For example, a gas turbine compressor with a casing treatment ("CT") is known. This comprises a circumferential or interrupted circumferential groove, which is arranged axially in the region of a circumferential blade tip and are arranged in the deflection means in the form of webs. In various embodiments, the webs on arbitrary radial recesses.

An object of an embodiment of the present invention is to improve a gas turbine compressor.

This object is achieved by a gas turbine compressor with the features of claim 1. Claims 15, 16 provide an aircraft engine with such a gas turbine compressor or a method for designing such a gas turbine compressor under protection. Advantageous embodiments of the invention are the subject of the dependent claims.

According to one aspect of the present invention, one, in particular axial, gas turbine compressor has one or more circumferentially juxtaposed blades with, in particular deckbandlosen, blade tips and this radially opposite flow channel wall.

In one embodiment, the gas turbine compressor is a gas turbine compressor for an aircraft engine or an aircraft engine; in particular, it may be a low-pressure compressor arranged upstream of another gas turbine compressor in a gas turbine or a high-pressure compressor arranged downstream of another gas turbine compressor. The blades are in a version a rotating rotatably mounted rotor, rotating in operation blades whose radially outer blade tips the housing-fixed flow channel wall radially outwardly opposite. In another embodiment, the blades are fixed to the housing vanes, which faces the rotating in operation, rotatably mounted Strömungskanalwandung radially inward.

In the Strömungskanalwandung a circumferential groove is arranged. In one embodiment, this has an upstream groove flank which merges into the flow channel wall in an upstream groove edge, a downstream groove flank which merges into a flow channel wall in a downstream groove edge, and a groove base which connects these groove flanks. In one embodiment, a groove edge may have a sharp-edged or angular or even rounded or have a radius, in which case the center edge or intersection of its two outermost tangents may define the groove edge for dimensions.

In one embodiment, the upstream groove flank and / or the downstream groove flank has an axial undercut whose cross-sectional area in a meridian section in a development is less than 10% of a cross-sectional area of the circumferential groove between its upstream and downstream groove edge.

A meridian section in the sense of the present invention is a plane section which contains the axis of rotation of the compressor. An axial undercut of the upstream groove flank is a region of this groove flank which is arranged in the axial direction upstream of the upstream groove edge. Correspondingly, an axial undercut of the downstream groove flank is a region of this groove flank which is arranged downstream in the axial direction behind the downstream groove edge. A cross-sectional area of the circumferential groove between its upstream and downstream groove edges is correspondingly the area delimited in the meridian section by the groove bottom, a straight connecting line between the upstream and downstream groove edges, and perpendiculars by the upstream and downstream groove edges.

The circumferential groove extends in one embodiment, in particular continuously or without interruption, over the full circumference of the flow channel wall or over 360 °. In other words, in one embodiment, the upstream and downstream groove edges are each a continuous edge that extends uninterrupted 360 °. As a result, in one embodiment, the production and / or aerodynamics of the circumferential groove can be improved.

In the circumferential groove one or more webs are arranged. A plurality of adjacent, in particular all, webs can be designed identically in one embodiment, in particular, at least substantially, have identical dimensions and contours. As a result, in one embodiment, the production and / or aerodynamics of the circumferential groove can be improved. Similarly, adjacent webs can be designed differently in one embodiment, in particular have different dimensions and / or contours. As a result, targeted asymmetries can be displayed or compensated in one embodiment. Three or more, in particular all, webs can be spaced equidistantly in the circumferential direction. Similarly, three or more, in particular all, webs in the circumferential direction in pairs have different distances from each other.

One or more, preferably all webs have a radial pruning. In the present case, a radial pruning means, in particular, an empty space between a blade-side end face of the web and its projection into a reference surface which extends from the upstream groove edge to the downstream groove edge, wherein the curvature of the reference surface in the meridian sections through the end face is equal to infinity or to the upstream and downstream groove edge is the same as the curvature of the flow channel wall and is continuously linear therebetween in the axial direction. In a meridian section, the radial cutback is understood as meaning the free area between a blade tip side upper edge of the cross section of the web and a reference curve extending from the upstream groove edge to the downstream groove edge, the curvature of the reference curve being equal to infinity or at the upstream and downstream groove edge equal to the curvature of the Strömungskanalwandung and between them in the axial direction is continuously linear. With others Words is a radial cutback in one embodiment, the empty space or the free surface between the blade-side end or upper edge of the web and a virtually on the circumferential groove away away flow channel contour understood, said virtual continuation contour be a straight connection level or line the groove edges can connect with a curvature which corresponds to the groove edges of the curvature of the flow channel contour and interpolated linearly therebetween.

According to one aspect of the present invention, in particular in one or more, preferably all, meridian sections through the blade tip side face of the web, an upstream beginning of the cutback is axially downstream of the upstream groove edge between that groove edge and the upstream leading edge of the blade tip and disposed downstream end of the cutback in a blade tip nearer half of a radial height of the circumferential groove.

Surprisingly, it has been found that an inventive pruning starting downstream of the upstream groove edge and upstream of the upstream leading edge of the blade tip and terminating in the blade tip nearer half of the circumferential groove, in one embodiment, has the advantages of casing structuring in non-flattening mode ("off-design "), at least substantially, while at the same time in the design mode or under nominal operating conditions unwanted flow phenomena can be reduced.

In an embodiment, an upstream start of the cutback is understood to be that axial position beyond which the blade-side end face or upper edge of the web deviates from the virtually continuous flow channel contour or the reference surface or curve away from the blade tip towards the groove bottom. In another embodiment, an upstream beginning of the cutback section is understood to be the axial position from which the blade-side end face or upper edge of the web from the straight reference surface or curve in the radial direction to the groove base by at least 1%, in particular at least 5% of a maximum Radial distance between a blade tip closer groove edge and the groove bottom deviates.

The upstream start of the cutback is arranged axially downstream of the upstream groove edge and upstream of the upstream leading edge of the blade tip according to the above aspect. Until the beginning of the cutback, the blade-side end face (or in one or more, preferably all, meridian sections through the blade tip side end face of the web, the upper edge) of the web in one embodiment, the flow channel contour with continuous curvature or without abrupt change in the curvature continues.

In a corresponding embodiment, a downstream end of the cutback section is understood to be that axial position at which the blade-side end face or upper edge of the web opens again into the reference surface or curve or into the downstream groove flank. In another embodiment, a downstream end of the recut section is understood to be that axial position from which the blade-side end face or upper edge of the web from the straight reference surface or curve to the groove bottom in the radial direction again by less than 5%, in particular less than 1 % of the maximum radial distance between the blade tip closer groove edge and the groove bottom deviates.

The downstream end of the cutback is arranged in a blade tip nearer half of a radial height of the circumferential groove according to the above aspect. In the sense of the present invention, a radial height of the circumferential groove is in particular a maximum distance between the groove base and the reference surface or curve, in particular a maximum distance between the groove base and the groove edge closer to the blade tip, in the radial direction or in a direction perpendicular to the connecting line understood upstream and downstream groove edge, wherein such a distance perpendicular to the connecting line generalizing is referred to as the radial height of the circumferential groove.

In one embodiment, the radial pruning terminates in the reference surface or curve, in a further embodiment axially upstream of or downstream of the upstream one Leading edge of the blade tip. Until the end of the cutback, the blade-side end face (or the upper edge in one or more, preferably all, meridian sections through the blade tip-side end face of the web) sets the flow channel contour with a continuous curvature or without an abrupt change in the curvature from the downstream in one embodiment Groove edge upstream.

In another embodiment, the radial cutback ends in the radially upper half of the downstream groove flank, the web is continuously cut back radially from the beginning of the cutback. As the radially upper half is generally referred to the part of the downstream groove flank extending in the radial direction or a direction perpendicular to the line connecting the upstream and downstream groove edge over 50% of the maximum distance of the downstream groove edge from the groove bottom in this direction.

In one embodiment, the web opens into the upstream and / or the downstream groove flank of the circumferential groove, so it can thus extend in particular axially through the groove or its maximum axial length.

Then, as already stated above, in one or more, in particular all meridian sections through the blade tip-side end face of the web, a blade tip-side upper edge of the web at the upstream groove edge may have the same curvature as the flow channel contour, i. at the upstream groove edge have a continuous curvature, and continue steadily until the beginning of the re-cut.

In a development, the web can be straight or curved or run. In particular, in one embodiment, the blade-side end face of the web, at least substantially, open axially into the upstream groove edge. Additionally or alternatively, the blade-side end face in or against a direction of rotation of the blade tip curved into the downstream groove edge open. Preferably, the surface of the cutback is limited in at least one meridian section to at most 30%, in particular at most 25% of the cross-sectional area of the circumferential groove. Accordingly, in one embodiment, the web in one or more, in particular all meridian sections through the blade tip side end face of the web on a cross-sectional area which is at least 70%, in particular at least 75%, the cross-sectional area of the circumferential groove in this meridian section. A cross-sectional area of the circumferential groove is, according to the above-described definition, the area delimited in the meridian section by the groove bottom, the groove flanks and a straight connecting line between the upstream and downstream groove edge.

In one embodiment, the circumferential groove encloses in one or more, in particular all meridian sections through the blade tip side end face of the web at the upstream edge of the groove with the flow channel wall at an angle which is between 60 ° and 90 °. In this way, in particular, an advantageous axial undercut can be represented.

In one embodiment, an axial distance between the upstream groove edge and the downstream edge of the blade tip downstream therefrom is greater than an axial distance between the downstream groove edge and the leading edge of the blade tip disposed therefrom. In other words, the leading edge of the blade tip is disposed between the upstream and downstream groove edges and closer to the downstream groove edge.

In one embodiment, an axial distance between the upstream and downstream groove edges is at least 25% of an axial distance between the upstream leading edge and a downstream trailing edge of the blade tip.

In a section perpendicular to a rotational axis of the compressor, the web may be straight or curved, wherein it or its tangents may be radial or inclined to the radial direction. Accordingly, in one embodiment in one or more, in particular all sections perpendicular to the axis of rotation of the compressor inclined by the blade tip side end face of the web of the web to the groove bottom of the circumferential groove in the direction of rotation of the blade tip, in particular by at least 25 ° and / or at most 65 ° to the radial direction.

Fig. 1

einen Teil eines Gasturbinenverdichters nach einer Ausführung der vorliegenden Erfindung in einem Meridianschnitt.

Further advantageous developments of the present invention will become apparent from the dependent claims and the following description of preferred embodiments. This shows, partially schematized, the only:

Fig. 1

a portion of a gas turbine compressor according to an embodiment of the present invention in a meridian section.

Fig. 1 shows in a meridian section a part of a gas turbine compressor according to an embodiment of the present invention and a designed according to an embodiment of the present invention gas turbine compressor. The meridian section contains the axis of rotation of the compressor (horizontal in Fig. 1 ), in the Fig. 1 vertical direction is a radial direction.

The gas turbine compressor has in the circumferential direction (perpendicular to the plane of the Fig. 1 ) juxtaposed blades with uncovered blade tips, of which in the meridian section of the Fig. 1 a blade tip 10 is partially shown, and a radially outwardly opposite housing fixed flow channel wall 20 on.

In the Strömungskanalwandung a circumferential groove is arranged, which has an upstream groove flank 31, which merges into an upstream groove edge 21 in the Strömungskanalwandung, a downstream groove flank 32, which merges in a downstream groove edge 22 in the flow channel wall, and a groove bottom 33 connecting these groove flanks.

The upstream groove flank has an axial undercut whose cross-sectional area in the meridian section is less than 10% of a cross-sectional area of the circumferential groove between its upstream and downstream groove edges. This cross-sectional area of the circumferential groove between its upstream and The downstream edge of the groove is the area that is in the meridian section of the Fig. 1 is limited by the groove bottom, a straight connecting line 24 between the upstream and downstream groove edge and perpendicular through the upstream and downstream groove edge, which in Fig. 1 dash-dotted lines are indicated, the cross-sectional area of the undercut corresponding to the area between the upstream groove flank 31 and the in Fig. 1 left dotted vertical lines on the connecting line 24th

In the circumferential groove a plurality of webs in the circumferential direction (perpendicular to the plane of the Fig. 1 ), of which in the meridian section of the Fig. 1 a web 40 is shown cut.

At 24 is in Fig. 1 As already explained above, a straight connecting line 24 between the upstream and downstream groove edge 21, 22 is designated. This thus represents a reference curve which extends from the upstream groove edge to the downstream groove edge, their curvature being equal to infinity.

At 23 is in Fig. 1 another reference curve, which also extends from the upstream groove edge to the downstream groove edge, wherein the curvature of this reference curve at the upstream and downstream groove edge is equal to the curvature of Strömungskanalwandung and therebetween in the axial direction is continuously linear, ie the curvature of Strömungskanalwandung 20th interpolated linearly between the groove edges 21, 22. This reference curve 23 thus continues the flow channel contour 20 virtually over the circumferential groove.

The reference curves 23, 24 each provide a corresponding reference surface 23, 24 extending in the circumferential direction in the meridian section of FIG Fig. 1 by a blade tip-side end face or upper edge 43 of the web 40.

As in the meridian section of the Fig. 1 recognizable, deviates the blade tip side end face or upper edge 43 from a point or a circumferential line 41 up to a further point or a further circumferential line 42 from the reference curve or surface 23 or the virtually continuous flow channel contour away from the blade tip towards the groove bottom radially (upward in FIG Fig. 1 ).

From the point or the circumferential line 41, the blade-side end face or upper edge 43 also deviates from the straight reference surface or curve 24 toward the groove base by at least 1% of a maximum radial distance between the groove edge 22 closer to the blade tip and the groove base 33.

The point or circumferential line 41 thus defines an upstream beginning of a radial cut-back 44 of the web.

Up to this beginning 41 of the cut-back 44, the blade-side end face or upper edge of the web continues the flow channel contour 20 with a continuous curvature.

The point or circumferential line 42 defines a downstream end of the radial cut-back 44, at which the blade-side end or upper edge 43 of the web opens into the downstream groove flank 32.

In a modification, not shown, the blade-side end face or upper edge 43 of the web, on the other hand, opens again into the reference surface or curve 23. Then, the point or the circumferential line on which or the blade-side end face or upper edge 43 of the web again opens into the reference surface or curve 23, or the point or the circumferential line, from which or the blade-side end face or upper edge of the web of the straight reference surface or curve 24 to the groove bottom 33 again by less than 1% the maximum radial distance between the blade tip closer groove edge 22 and the groove bottom 33 deviates, the downstream end of the radial cutback.

In this modification, not shown, the blade-side end face or upper edge of the web, the flow channel contour with continuous curvature of the downstream groove edge 22 upstream (to the left in Fig. 1 ) until this end of the pruning, as shown analogously for the area between the upstream groove edge 21 and the upstream beginning 41 of the pruning.

The empty space or the free area between the blade-side end face or upper edge 43 of the web and the reference surface or curve 23 thus defines the radial cutback 44 with its upstream end 41 and its downstream end 42.

As in the meridian section of the Fig. 1 recognizable, this upstream beginning 41 of the cutback 44 becomes axially downstream (right in FIG Fig. 1 ) from the upstream groove edge 21 between this groove edge 21 and the upstream leading edge 11 of the blade tip 10 and the downstream end 42 of the cutback 44 are located in a blade tip nearer half 34 of a radial height 35 of the circumferential groove.

In this case, the maximum distance between the groove base 33 and the blade tip closer groove edge 22 in the radial direction (vertically in Fig. 1 ) or, as in Fig. 1 indicated, the maximum distance 35 between the groove base 33 and the blade tip closer groove edge 22 may be defined in a direction perpendicular to the straight connecting line 24 of the upstream and downstream groove edge.

In the illustrated embodiment, the radial cutback ends in the radially upper half 34 of the downstream groove flank 32, the web is continuously cut back radially from the beginning 41. The radially upper half is the part or region of the downstream groove flank 32 which extends in the radial direction or the direction perpendicular to the connecting line 24 of the upstream and downstream groove edge over 50% of the maximum distance of the downstream groove edge 22 from the groove base 33 in this direction ,

In the execution of Fig. 1 the web 40 terminates in the upstream and downstream groove flanks 31, 32 of the circumferential groove, thus extending axially through the groove.

As already explained above, the blade tip-side end face or upper edge of the web at the upstream groove edge 21 has the same curvature as the flow channel contour 20 and steadily continues it until the beginning 41 of the cut-back 44.

In the execution of Fig. 1 the web 40 has an in Fig. 1 hatched indicated cross-sectional area, which is at least 75% of the cross-sectional area of the circumferential groove in this meridian section, which is defined by the groove flanks 31, 32, the groove bottom 33 and the connecting line 24 between the two groove edges 21, 22.

In the execution of Fig. 1 closes the circumferential groove at the upstream groove edge 21 with the Strömungskanalwandung 20 an angle α, which is between 60 ° and 90 °.

In the execution of Fig. 1 is an axial distance between the upstream groove edge 21 and the downstream thereof (right in FIG Fig. 1 ) disposed leading edge 11 of the blade tip 10 is greater than an axial distance between the downstream groove edge 22 and the front edge 11 thereof arranged upstream.

In the execution of Fig. 1 For example, an axial distance between the upstream and downstream groove edges 21, 22 is at least 25% of an axial distance between the upstream leading edge 11 and a downstream trailing edge (not shown) of the blade tip 10.

Although exemplary embodiments have been explained in the foregoing description, it should be understood that a variety of modifications are possible. It should also be noted that the exemplary embodiments are merely examples of the scope, applications and applications should not limit the structure in any way. Rather, the expert is given by the preceding description, a guide for the implementation of at least one exemplary embodiment, with various changes, in particular with regard to the function and arrangement of the components described, can be made without departing from the scope, as it turns out according to the claims and these equivalent combinations of features.

LIST OF REFERENCE NUMBERS

10

blade tip

11

leading edge

20

Flow channel contour

21

upstream groove edge

22

downstream groove edge

23

Reference surface / curve

24

straight reference surface / curve

31

upstream groove flank

32

downstream groove flank

33

groove base

34

blade tip closer half of the circumferential groove

35

radial height of the circumferential groove

40

web

41

upstream beginning of the cutback

42

downstream end of the cutback

43

blade tip side face / top edge

44

pruning

α

angle

Claims (16)

Gas turbine compressor, with at least one blade tip (10) and one of these radially opposite Strömungskanalwandung (20), in which a circumferential groove (31-33) is arranged, in which at least one web (40) is arranged, which has a radial cutback (44) ;
characterized in that
an upstream start (41) of the cutback axially downstream of an upstream groove edge (21) between said groove edge and an upstream leading edge (11) of the blade tip and a downstream end (42) of the cutback in a blade tip closer half (34) of a radial height (35) ) of the circumferential groove is arranged. Gas turbine compressor according to claim 1, characterized in that the web opens into an upstream and / or a downstream groove flank (31, 32) of the circumferential groove. Gas turbine compressor according to the preceding claim, characterized in that in at least one meridian section a blade tip side upper edge (43) of the web at the upstream groove edge, in particular to the beginning of the cutback, has a continuous curvature. Gas turbine compressor according to one of the two preceding claims, characterized in that a blade-side end face (43) of the web, at least substantially, axially opens into the upstream groove edge and / or in or against a rotational direction of the blade tip curved in the downstream groove edge. Gas turbine compressor according to one of the preceding claims, characterized in that the web in at least one meridian section has a cross-sectional area which is at least 70%, in particular at least 75%, of a cross-sectional area of the circumferential groove. Gas turbine compressor according to one of the preceding claims, characterized in that the circumferential groove extends over the full circumference of the flow channel wall. Gas turbine compressor according to one of the preceding claims, characterized in that the circumferential groove in at least one meridian section at the upstream groove edge with the Strömungskanalwandung an angle (α) includes, which is between 60 ° and 90 °. Gas turbine compressor according to one of the preceding claims, characterized in that an axial distance between the upstream edge of the groove and the downstream edge of the blade tip is greater than an axial distance between the downstream edge of the groove and the leading edge of the blade tip arranged upstream thereof. A gas turbine compressor according to any one of the preceding claims, characterized in that an axial distance between the upstream and downstream groove edges is at least 25% of an axial distance between the upstream leading edge and a downstream trailing edge of the blade tip. Gas turbine compressor according to one of the preceding claims, characterized in that the web is inclined in at least one section perpendicular to a rotational axis of the compressor to a groove bottom of the circumferential groove in the direction of rotation of the blade tip, in particular by at least 25 ° and / or at most 65 ° against a radial Direction. Gas turbine compressor according to one of the preceding claims, characterized in that in the circumferential groove at least three identical or different webs are arranged in the circumferential direction equidistant or with different distances from each other. Gas turbine compressor according to one of the preceding claims, characterized in that the blade tip is a radially outer blade tip (11) of a blade (10), which faces the Strömungskanalwandung radially outward. Gas turbine compressor according to one of the preceding claims 1 to 12, characterized in that the blade tip is a radially inner blade tip of a vane, which faces the flow channel wall radially inward. Gas turbine compressor according to one of the preceding claims 1 to 12, characterized in that an upstream groove flank (31) and / or a downstream groove flank (32) of the circumferential groove having an axial undercut whose cross-sectional area in a meridian section less than 10% of a cross-sectional area of the circumferential groove between its upstream and downstream groove edge. An aircraft engine with a gas turbine compressor according to one of the preceding claims. A gas turbine compressor design according to any one of the preceding claims, characterized in that an upstream start (41) of the rear cut axially downstream of an upstream groove edge (21) between said groove edge and an upstream leading edge (11) of the blade tip and a downstream end (42) ) of the cutback is located in a blade tip nearer half (34) of a radial height (35) of the circumferential groove.

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