EP3431708A1 - Flow assembly, corresponding turbomachine and use - Google Patents

Abstract

The invention relates to a bypass arrangement (20) for arranging in the hot gas duct of a turbomachine (1), having a first flow structure (6) and a second flow structure (21), which flow structures (6, 21) with respect to the flow around in the hot gas channel Leading edge (6a, 21a) and downstream thereof have a trailing edge (6b, 21b), wherein the second Umströmungsstruktur (21) is provided as a turning vane with a suction side and a pressure side and a smaller profile thickness than the first flow around structure (6), which on the second Umströmungsstruktur (21) is arranged, and wherein the second Umströmungsstruktur (21) with respect to a longitudinal axis (2) of the turbomachine (1) with the first Umströmungsstruktur (6) Although a partial axial overlap, but at the same time the trailing edge ( 21b) of the second bypass structure (21) to the trailing edge (6b) of the first bypass structure (6) axially downstream is offset.

Description

Technical area

The present invention relates to a Umströmungsanordnung with Umströmungsstrukturen for arranging in the hot gas duct of a turbomachine.

State of the art

When the turbomachine may, for example. To act a jet engine, z. B. a turbofan engine. Functionally, the turbomachine is divided into compressor, combustion chamber and turbine. For example, in the case of the jet engine, sucked air is compressed by the compressor and burned in the downstream combustion chamber with added kerosene. The resulting hot gas, a mixture of combustion gas and air, flows through the downstream turbine and is thereby expanded. The volume flowed through by the hot gas, ie the path from the combustion chamber via the turbine to the nozzle, is referred to as "hot gas channel".

The presently in question Umströmungsanordnung is provided for arranging in the hot gas channel and has a plurality of Umströmungsstrukturen. Of these, at least some are designed as turning vanes, while others are preferably struts or corresponding linings. Like the above reference to a jet engine, this is intended to illustrate the present subject matter, but not to limit its generality at first. The turbomachine may, for example, also be a stationary gas or steam turbine.

Presentation of the invention

The present invention is based on the technical problem of specifying a particularly advantageous flow-through arrangement for arranging in the hot gas duct of a turbomachine.

According to the invention this object is achieved with the Umströmungsanordnung according to claim 1. This has a first and a second Umströmungsstruktur, wherein the second Umströmungsstruktur is provided as a Umlenkschaufel and has a smaller profile thickness than the first Umströmungsstruktur, which is arranged on the suction side of the second Umströmungsstruktur. Further, although the Umströmungsstrukturen are arranged with a partial axial overlap, but at the same time the trailing edge of the second Umströmungsstruktur offset from the first Umströmungsstruktur axially downstream. Figuratively speaking, with the present Umströmungsanordnung initially different Umströmungsstrukturen that are provided axially successively in a conventional design in separate sections, pushed a piece far into each other (axial overlap), but not completely.

By the rear edge of the second Umströmungsstruktur (hereinafter also "thin turning vane") is offset to the rear, at the trailing edge of the first Umströmungsstruktur (hereinafter also "thick blade"), a suction can be generated. Thus, the flow can be accelerated away from the trailing edge of aerodynamically unfavorable thick blade and can refine the caster or even, which, for example, reduce harmful secondary flows and can also reduce noise. Figuratively speaking, the thin turning vane causes a discharge and a smooth outflow at the trailing edge of the thick blade (Kutta condition). This can be advantageous in view of the uniformity of the flow to the downstream rotor or also help improve the efficiency of the turbine as a whole, for example. By about 0.25% to 0.5%.

Preferred embodiments are to be found in the dependent claims and the entire description, wherein in the representation of the features is not always distinguished in detail between the Umströmungsanordnung or a corresponding turbomachine or associated uses, in any case, implicitly, the disclosure in terms of all claim categories to read.

Each of the Umströmungsstrukturen has a front and a rear edge, in between each extending two opposite side surfaces of the respective Umströmungsstruktur. The profile thickness is taken between the side surfaces. In detail, the skeleton line extends centrally between the side surfaces between the leading and trailing edges of the respective flow structure, and then the profile thickness results as the largest circle diameter on the skeleton line (the circle touches the side surfaces, the center is on the skeleton line). The thin deflecting blade may, for example, have a profile thickness that is at least 50%, 60%, 70% or 80% lower than the first circulating structure, with possible (independent) upper limits at, for example, at most 99%, 97% or 95% ( each increasingly preferred in the order of entry).

As far as in the context of this disclosure, different structures are compared with each other, such as the Umströmungsstrukturen with each other or with other blades of the turbine (see below), the design of the respective structure is based in their respective radial center. In each case, the shape at half the height (taken radially) of the corresponding circulating structure or the deflecting blade or of the airfoil is considered. Radially in the middle of the gas channel, the influence on the flow can be greatest. Preferably, however, the respective structures are nevertheless configured correspondingly over their entire height relative to one another (in any case when compared in each case with the same percentage of height).

In general, in the context of this disclosure, "axial" refers to the longitudinal axis of the turbomachine, which, for example, coincides with an axis of rotation of the rotors. "Radial" refers to the perpendicular to it, pointing away radial directions, and a "circulation" or "circumferential" or the "direction of rotation" relate to the rotation about the longitudinal axis. The first and the second flow around structure are, for example, due to the axial overlap, arranged successively in the direction of rotation. In other words, "axial" overlap, for example, means that a projection of the first circulating structure radially on the longitudinal axis with a projection of the second circulating structure radially on the longitudinal axis has an overlap.

Within the scope of this disclosure "one" and "one" are to be read as indefinite articles and thus always as "at least one" or "at least one". Over a complete circulation around the longitudinal axis the Umströmungsanordnung can of course have a plurality of first and second Umströmungsstrukturen, eg. At least 4, 5 or 6, with possible (independent) upper limits for example. At most 30, 20 or 15. In each case with each other are the first and the second Umströmungsstrukturen then preferably identical and arranged rotationally symmetrical. As will be apparent in detail below, there may also be third and possibly fourth or even further Umströmungsstrukturen, which are then also designed as thin deflection vanes. Thus, for example, there may be at least two and preferably no more than nine, eight, seven, six, five, four or three thin deflecting vanes running around each other between two thick blades.

In a preferred embodiment, the first flow around structure is provided as a supporting strut or as a lining, in particular as a lining of a supporting strut support. The support strut is a load-bearing component of the turbomachine, preferably it (together with further peripherally arranged support struts) supports the bearing of the turbine shaft, in particular the high-pressure turbine shaft. The bearing is preferably arranged in the turbine intermediate housing, in the so-called. Mid Turbine Frame. The support struts can each extend away from the bearing radially outward and keep the bearing centered in the housing, so to speak spoke-shaped.

Preferably, the first Umströmungsstruktur is a panel in which, for example. A supply line may be performed, it is preferably a panel of a support strut, it is therefore attached for aerodynamic reasons to the actually bearing component. Also in this case, additional supply lines etc. can then be performed. Such a panel is also known as fairing. The supporting function or enclosing the support strut require a certain structure size, ie large profile thickness. This is aerodynamically disadvantageous, but this is at least partially compensated by the combination with the thin turning vane.

The first flow-around structure may generally also be non-deflecting, preferably it is slightly deflecting at less than 5 °, but it has no effect on the flow (due to radius change and spin set, no momentum is transferred to the flow). The thin turning vane is the first flow around structure (thick vane) with its bottom surface facing. At the bottom of the thick blade more deflection is necessary because its bottom surface due to the high thickness substantially axially into the trailing edge runs, for example. Not tilted by more than 10 ° or 5 ° to the axial direction. The thin turning vane creates at the trailing edge the thick blade once an acceleration (nozzle effect). Next, the tail is "sucked away" from the trailing edge.

In a preferred embodiment, the thin turning vane has its maximum curvature where it has the axial overlap with the first flow around structure. This high-curvilinear design is similar to a wing with the Fowler flap extended, further increasing the suction created at the trailing edge of the thick blade.

In a preferred embodiment, the trailing edge of the thin turning vane is at least 0.5 times, more, and most preferably at least 0.7 or 0.9 times the axial length of the blading of a downstream rotor directly downstream of the trailing edge first Umströmungsstruktur offset (axially downstream). Preferred upper limits, which in general may also be of interest independently of the lower limits, are at most 4 times, more, and particularly preferably at most 2.6 or 2.2 times. The "axial length" results as the axial portion of the chord length of the blades of the rotor (if it is equipped with different blades, a mean value formed over this is considered).

In a preferred embodiment, the leading edge of the thin turning vane is offset axially downstream of that of the thick vane. Preferably, an offset of at least 0.4, 0.5 or 0.6 times the axial length of the first flow structure (thick blade), ie the axial portion of the chord length. Advantageous upper limits are (also independent of) at preferably at most 1.2 times, more preferably at most 0.9 times.

In a preferred embodiment, the thin turning vane has a chord length that is at least 1 times, preferably at least 1.5 times, a chord length of the blading of the downstream immediately downstream rotor. Should this be equipped with different blades, again an average value is considered. Advantageous upper limits of the chord length of the thin turning vane are in the order of naming increasingly preferred at most 8, 7, 6, 5, 4, or 3 times the chord length of the subsequent rotor. Thus, a tendon length of about 2 to 3 times is particularly preferred.

In a preferred embodiment, the Umströmungsanordnung on a third Umströmungsstruktur which analogous to the second Umströmungsstruktur provided as a thin Umlenkschaufel, to the second Umströmungsstruktur but not identical. The third flow-around structure is arranged on the upper side of the thick blade (the thick blade lies on the suction side of the third flow-around structure). Circumferentially between two thick blades, at least two different thin deflection vanes are then provided in each case. The trailing edge of the third flow-around structure is preferably axially offset downstream of that of the thick blade, with respect to that of the second flow-around structure it is preferably axially offset-free (not offset), which preferably also applies to a fourth or generally further flow-around structures.

In a preferred embodiment, the third circulating structure has a smaller chord length than the second circulating structure. As stated above, more diversion may be required at the bottom of the first bypass structure, which is achieved with the greater chord length of the second bypass structure. If more than two different thin deflection vanes are provided circumferentially between two first flow-around structures, they preferably have a decreasing chord length overall from the underside of one thick blade to the upper side of the other thick blade. With the variable chord length, the free flow cross-section can be adjusted so that a uniform flow of the subsequent rotor is achieved.

In a preferred embodiment, the third flow structure has a smaller curvature than the second. It is thus achieved with a more curved second Umströmungsstruktur at the bottom of the thick blade more deflection, see the front. If more than two different thin deflection blades are provided circumferentially between two first flow-around structures, they preferably have a decreasing curvature overall from the underside of one thick blade to the upper side of the other thick blade.

In a preferred embodiment, a further thin deflection vane is provided (fourth flow around structure), wherein the second, third and fourth Umströmungsstruktur are not identical to each other. The fourth flow around structure is the suction side of the arranged third Umströmungsstruktur. If exactly three different thin deflecting vanes are arranged circumferentially between two thick blades, a fourth circulating structure is also arranged on the pressure side of the second circulating structure.

In a preferred embodiment, the fourth Umströmungsstruktur has a greater chord length than the third Umströmungsstruktur or it is more curved, preferably both. The chord length and / or curvature preferably increases from the third circulating structure via the fourth to the second circulating structure.

In a preferred embodiment, at least four Umströmungsstrukturen are arranged between two first Umströmungsstrukturen which are adjacent to each other in the circumferential direction, which are each formed as a Umlenkschaufel. Upper limits independent of this lower limit may be more preferably at most twelve, eleven, ten or nine deflection vanes in the order of entry. Particularly preferred may be exactly four deflecting vanes. The second, third, fourth and fifth bypass flow structures can therefore preferably be arranged between the first bypass flow structures adjacent to one another, cf. also the above description with further details.

As far as a plurality of deflecting vanes are generally provided between two first Umströmungsstrukturen, the latter can be offset from each other with their trailing edges, so be staggered. With reference to the direction of rotation, an equidistant arrangement of the trailing edges of the deflecting vanes is generally also possible, but a non-equidistant arrangement may be preferred.

In a preferred embodiment, at least the deflection vanes arranged between the two adjacent first circulation flow structures in the direction of circulation are formed as a multiple segment. The first flow-around structure may also be provided as part of the multiple segment. On the other hand, a subdivision can be advantageous in that only the deflecting vanes are combined in multiple segments or in a ring, wherein the first Umströmungsstrukturen are then assembled with it. The first Umströmungsstruktur or structures are then poured so for themselves; then to the axial overlap realize, in each case a recess can then be introduced into the trailing edges of the first Umströmungsstrukturen, z. B., in which then the segment or the wreath is inserted with the turning vanes. The flow-around structures of the multiple segment or ring are integrally with each other, that is not non-destructively separable, preferably they can be monolithic, in particular formed from a cast.

The invention also relates to a turbomachine with a presently disclosed Umströmungsanordnung, this may be arranged in particular in the turbine intermediate housing.

Likewise, the invention relates to the use of a presently disclosed Umströmungsanordnung in a turbomachine, in particular an aircraft engine.

Brief description of the figures

In the following, the invention will be explained in more detail with reference to an exemplary embodiment, wherein the individual features in the context of the independent claims in another combination may be essential to the invention and continue to distinguish not in detail between the different claim categories.

Figur 1a

ein Strahltriebwerk in einem Schnitt;

Figur 1b

eine schematische Detailansicht zu Figur 1a;

Figur 2

eine erfindungsgemäße Umströmungsanordnung im Turbinenzwischengehäuse des Strahltriebwerks gemäß Figur 1.

Figur 3

die Lage der Teilkanäle mit Beschleunigung (Düse) sowie das Sogfeld der Umlenkschaufeln.

In detail shows

FIG. 1a

a jet engine in a section;

FIG. 1b

a schematic detail view too FIG. 1a ;

FIG. 2

a Umströmungsanordnung invention in the turbine intermediate housing of the jet engine according to FIG. 1 ,

FIG. 3

the position of the sub-channels with acceleration (nozzle) and the suction field of the turning vanes.

Preferred embodiment of the invention

FIG. 1a shows a turbomachine 1 in section, specifically a jet engine. FIG. 1b shows a schematic detail view thereto, the following comments relate to both figures. Functionally, the turbomachine 1 is divided into compressor 1a, combustion chamber 1b and turbine 1c. Both the compressor 1a and the turbine 1c are each constructed of several stages, each stage is usually composed of a guide and a blade ring. During operation, the rotor blade rings rotate about the longitudinal axis 2 of the turbomachine 1. The turbine shaft 3 is guided in a bearing 4, which is held by struts 5 (partially dashed) in the remaining turbomachine 1. In the area of the hot gas channel, each of the support struts 5 is jacketed for aerodynamic and thermal reasons, namely from a first Umströmungsstruktur 6, illustrating a cover and is also known as fairing. This section is a so-called Turbinenzwischengehäuse. In the turbomachine according to the invention this is carried out integrally with the subsequent vane ring.

FIG. 2 shows a portion of the Umströmungsanordnung 20 of the invention, which is arranged in the turbine intermediate housing in the hot gas duct. Shown is a section, the cut surface is radially in the middle in the hot gas channel and parallel to the longitudinal axis 2. In addition to the first flow structures 6 (fairings) second Umströmungsstrukturen 21 and third Umströmungsstrukturen 22 can be seen, each as a Umlenkschaufel with a suction side (in the figure above ) and a pressure side (in the figure below) are formed. The profile thickness of these thin deflection vanes is only about 30% of the profile thickness of the first flow structures 6 (in the schematic representation according to FIG FIG. 2 the thin vanes are simplified as lines without profile thickness reproduced).

The flow-around structures 6, 21, 22 each have a front edge 6a, 21a, 22a and, downstream thereof, a respective trailing edge 6b, 21b, 22b. Although the thin deflecting vanes are provided axially with an overlap with respect to the first circulating structures 6, they are also offset a little. The trailing edges 21b, 22b of the second and third circulating structures 21, 22 are offset axially downstream from the trailing edges 6b of the first circulating structures 6. In addition, the second Umströmungsstruktur 21 has its strongest curvature in the axial overlap with As a result, a strong suction is generated and the flow accelerated away from the trailing edge 6b of the aerodynamically rather unfavorable first flow structure 6. The caster becomes finer and more uniform, cf. also the presentation in the introduction to the description.

At the bottom of the first bypass structure 6 (in the figure below), the flow must be deflected more strongly than at the top, because the lower side surface substantially axially into the trailing edge 6b due to the larger wedge angle or the large thickness. Therefore, the second bypass structure 21 is more curved than the third bypass structure 22 and has a greater chord length. The first flow around structure 6 is arranged on the pressure side of the third flow around structure 22, this presses the flow at the trailing edge 6b a little way down and thus relieves the trailing edge 6b.

FIG. 3 shows an enlarged view of the configuration FIG. 2 with the suction field 23 on the upper side of the thin deflecting vane 21. Both deflecting vanes 21, 22 form with the circulating structure 6 in their inlet region narrowing flow channels 24, 25, which lead to a further relief of the flow at the trailing edge 6b. Downstream of the trailing edge 6b, close to the narrow gap 26, there is a further narrowing flow channel, which generates the suction field together with the blade curvature. There are so Umströmungsstrukturen 6 with high thickness and thickness reserves x _d / L> 50% possible, which can accommodate more and larger supply lines and support elements. A reduction in the number of blades, friction loss and weight is possible.

In this example, the bypass arrangement 20 is constructed in total (over the entire circulation) from in each case 9 first, second and third flow-around structures 6, 21, 22, ie has 18 thin deflection vanes. It could also be provided in addition a fourth, also designed as a thin Umlenkschaufel Umströmungsstruktur, so that would be arranged between two first Umströmungsstrukturen 6 each three different thin deflection vanes (in this case, a total of 27 thin deflection vanes are provided), see. also the description introduction. Independently of this, a group-by-group combination of the flow-around structures 6, 21, 22 in multiple segments is preferred. In this regard, the axial offset manufacturing technology advantageous or would be vice versa sometimes considerably more expensive to achieve the same flow guide at the trailing edge 6b of the first Umströmungsstruktur 6 by a long drawn back to the first Umströmungsstruktur 6.

The axial offset between the trailing edges 21b, 22b of the second and third flow structures 21, 22 to the trailing edges 6b of the first flow structures 6 corresponds to approximately 1.5 axial lengths of a subsequent rotor 30, specifically its blading 31. The described refinement and homogenization of the flow is also advantageous for the operation of the rotor 30.

LIST OF REFERENCE NUMBERS

flow machine 1 Longitudinal axis (the turbomachine) 2 turbine shaft 3 Bearing (the turbine shaft) 4 support struts 5 First flow around structure 6 Leading edge of it 6a Trailing edge of it 6b Umströmungsanordnung 20 Second flow structure 21 Leading edge of it 21a Trailing edge of it 21b Third flow structure 22 Leading edge of it 22a Trailing edge of it 22b Sogfeld 23 flow channels 24, 25 Engabstand 26 rotor 30 Blading (of the rotor) 31

Claims (15)

Umströmungsanordnung (20) for placing in the hot gas duct of a turbomachine (1), with a first flow around structure (6) and a second flow around structure (21), which flow-around structures (6, 21) have a front edge (6a, 21a) with respect to the flow around the hot-gas channel and a trailing edge (6b, 21b) downstream thereof, wherein the second bypass structure (21) is provided as a deflecting blade with a suction side and a pressure side and has a smaller profile thickness than the first bypass structure (6), which is arranged on the suction side of the second bypass structure (21), and wherein the second Umströmungsstruktur (21) with respect to a longitudinal axis (2) of the turbomachine (1) with the first Umströmungsstruktur (6) Although a partial axial overlap, but at the same time the trailing edge (21b) of the second Umströmungsstruktur (21) to the trailing edge (6b) of the first flow around structure (6) is offset axially downstream. The bypass arrangement (20) according to claim 1, wherein the first flow-around structure (6) is provided as a supporting strut or casing of such. The bypass arrangement (20) according to claim 1 or 2, wherein the second bypass structure (21) has a maximum curvature where it has the axial overlap with the first bypass structure (6). The bypass arrangement (20) according to any one of the preceding claims, wherein the trailing edge (21b) of the second bypass structure (21) to the trailing edge (6b) of the first bypass structure (6) by at least 0.5 times and at most the 4.0- is offset axially downstream of an axial length of the blading (31) of a rotor (30) arranged downstream immediately downstream. The bypass assembly (20) of any of the preceding claims, wherein the leading edge (21a) of the second bypass structure (21) is offset axially downstream from the leading edge (6a) of the first bypass structure (6) by at least 0.4 times and at most 1.2 times an axial length of the first bypass structure (6). The bypass arrangement (20) according to any one of the preceding claims, wherein the second flow around structure (21) has a chord length at least 1 times and at most 8 times a chord length of the blading (31) of a downstream rotor (30). accounts. Umströmungsanordnung (20) according to any one of the preceding claims with a third Umströmungsstruktur (22), which is provided as a turning vane with a suction side and a pressure side and a smaller profile thickness than the first Umströmungsstruktur (6), while the second and the third Umströmungsstruktur ( 21, 22) are shaped differently, wherein the first Umströmungsstruktur (6) on the pressure side of the third Umströmungsstruktur (22) is arranged. The bypass arrangement (20) of claim 7, wherein the third Umströmungsstruktur (22) has a smaller chord length than the second Umströmungsstruktur (21). The bypass arrangement (20) according to claim 7 or 8, wherein the third bypass structure (22) has a smaller curvature than the second bypass structure (21). 8. Umströmungsanordnung (20) according to any one of claims 7 to 9 with a fourth Umströmungsstruktur, which is provided as a turning vane with a suction side and a pressure side and a smaller profile thickness than the first Umströmungsstruktur (6), while the second, third and fourth Umströmungsstruktur ( 21, 22) are shaped differently, wherein the fourth Umströmungsstruktur on the suction side of the third Umströmungsstruktur (22) is arranged. The bypass arrangement (20) according to claim 10, wherein the fourth flow around structure has a greater chord length and / or curvature than the third flow around structure (22). Umströmungsanordnung (20) according to any one of the preceding claims, wherein at least two and not more than twelve each provided as a Umlenkschaufel with a suction side and a pressure side Umströmungsstrukturen (21, 22) are arranged circumferentially between two circumferentially adjacent first Umströmungsstrukturen (6). Umströmungsanordnung (20) according to claim 12, wherein at least the Umströmungsstrukturen (21, 22) arranged between the two next Umströmungsstrukturen next adjacent in the circumferential direction (21) are formed as a multi-segment. Turbomachine (1) with a bypass arrangement (20) according to one of the preceding claims, in particular arranged in a turbine intermediate housing. Use of a bypass arrangement (20) according to one of claims 1 to 13 in a turbomachine (1), in particular in an aircraft engine.

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