Flow machine with a flow channel

Abstract

The invention relates to a turbomachine (10) having a flow channel (11) with an annular inlet opening (31) and an annular outlet opening (41), wherein the inlet opening (31) and the outlet opening (41) are connected by means of an inner and an outer circumferential surface (24, 25) which radially delimit the flow channel (11), wherein the flow channel (11) has a plurality of radially extending struts (21) arranged distributed in the circumferential direction, the leading edges (21a) of which are arranged at a distance (D1) from trailing edges (22b) of upstream guide vanes (22) and the trailing edges (21b) of which are arranged at a distance (D2) from leading edges (23a) of downstream guide vanes (23).

Description

[0001] The invention relates to a turbomachine having a flow channel with an annular inlet opening and an annular outlet opening, wherein the inlet opening and the outlet opening are connected by means of an inner and an outer circumferential surface which radially delimit the flow channel, wherein the flow channel has a plurality of radially extending struts distributed in the circumferential direction which are arranged between upstream and downstream guide vanes.

[0002] Turbomachines, for example for aircraft propulsion, typically have multiple compressors, multiple turbines, and a combustion chamber. The multiple compressors are usually a low-pressure compressor and a high-pressure compressor, while the multiple turbines are a high-pressure turbine and a low-pressure turbine. Flow through the turbomachine is axial, with the low-pressure compressor positioned upstream of the high-pressure compressor and the high-pressure turbine upstream of the low-pressure turbine. For example, a transition duct can be arranged between the low-pressure compressor and the high-pressure compressor to guide the flow between these two compressors. A similar transition duct can be positioned between the high-pressure turbine and the low-pressure turbine.A flow guidance of a gas flow within the turbomachine and thus also in such a transition channel can have particularly favorable effects on the efficiency of the turbomachine.

[0003] Based on this, it is an object of the present invention to propose an improved turbomachine, particularly for aircraft propulsion. In particular, the turbomachine is intended to enable a reduction in overall length and / or an improvement in efficiency. This is achieved according to the invention by the teaching of the independent claim. Advantageous embodiments of the invention are the subject of the dependent claims.

[0004] To achieve this object, a turbomachine, in particular for aircraft propulsion, is proposed, comprising a flow channel with an annular inlet opening and an annular outlet opening, wherein the inlet opening and the outlet opening are connected by means of an inner and an outer casing surface which radially delimit the flow channel. The flow channel has a plurality of radially extending struts distributed in the circumferential direction, the leading edges of which are arranged at a distance from the trailing edges of upstream guide vanes and the trailing edges of which are arranged at a distance from the leading edges of downstream guide vanes. The inlet opening and the outlet opening of the flow channel are each arranged half the distance between the leading and trailing edges.Trailing edges of the struts and the leading and trailing edges of the adjacent guide vanes are arranged along a central geometry extending between the guide vanes, with each point of the central geometry being arranged at an equal distance from the inner and outer surface in a direction perpendicular thereto. An axial length of the flow channel, relative to the rotational axis of the turbomachine, extends from an intersection point of the inlet opening with the central geometry in the axial direction to an intersection point of the outlet opening with the central geometry, and a radial height of the flow channel extends from the intersection point of the inlet opening with the central geometry in the radial direction to an intersection point of the outlet opening with the central geometry.In this case, a length ratio of the axial length and the radial height and a cross-sectional ratio of the cross section of the inlet opening and the cross section of the outlet opening are in a range having a cross-sectional ratio between approximately 1 and approximately 1.2 and a length ratio between approximately 0.9 and approximately 1.5.

[0005] Due to the proposed specifications for the length ratio, the flow channel can have a comparatively steep or aggressive gradient, which enables a shortening of the overall length. The proposed specifications regarding the cross-sectional ratio can provide a, in particular predetermined, deceleration of a gas flow through the flow channel in order to reduce the risk of flow separation. The resulting shortening of the overall length of the turbomachine can achieve a reduction in fuel consumption and / or an improvement in the efficiency of the turbomachine.

[0006] A turbomachine proposed here can be intended for use in aircraft propulsion and, in particular, has a fan, a compressor, a combustion chamber, and a turbine, and can be designed, for example, as a turbofan engine. By means of the fan, ambient air can be drawn in as a working fluid or gas flow and compressed in the compressor to increase the pressure, in particular progressively in the direction of flow. In the combustion chamber arranged downstream of the compressor in the flow direction of the engine, the compressed working fluid can be burned with a fuel to generate combustion gases at high pressure and high temperature. The combustion gases flow as a gas flow from the combustion chamber to the turbine, where they expand to perform work. In particular, the expansion of the combustion gases in the turbine section drives a rotor or shaft.For example, a high-pressure turbine can drive a high-pressure compressor of the compressor via a high-pressure shaft and / or a low-pressure turbine can drive the fan via a low-pressure shaft.

[0007] In one embodiment, the flow channel is configured to connect at least two components of a turbomachine through which a gas flow can flow. Accordingly, the flow channel can be configured to connect two compressors of the turbomachine, and in particular to connect a high-pressure compressor and a low-pressure compressor of the turbomachine arranged downstream of it in the direction of flow of the gas flow. Accordingly, the flow channel can be arranged between two components through which the gas flow can flow, between two compressors, or between the low-pressure compressor and the high-pressure compressor.

[0008] The annular inlet opening is configured to connect, in particular continuously, to the upstream component of the turbomachine, thus enabling smooth, in particular laminar flow guidance. The outlet opening is configured to connect, in particular continuously, to a downstream component of the turbomachine, thus enabling smooth, in particular laminar flow guidance. The struts of the flow channel can be designed to guide and / or direct flow and / or can be configured to improve the flow quality for components arranged downstream in the flow direction.A leading edge in the sense of the present disclosure is that edge of a strut or guide vane of the turbomachine which is arranged upstream in the flow direction; a trailing edge is correspondingly an edge of a strut or guide vane of the turbomachine which is arranged downstream in the flow direction.

[0009] The guide vanes can each be part of a turbomachine component, such as a compressor or low-pressure compressor and / or high-pressure compressor. The upstream guide vanes can, for example, be part of an outlet guide vane of a low-pressure compressor, and the downstream guide vanes can be part of an inlet guide vane of a low-pressure compressor.

[0010] The central geometry can be described, for example, as a surface created by rotating a curve, in particular an S-curve, around the rotational axis of the turbomachine, and can essentially have a bell shape. The central geometry can have a larger diameter at an upstream position in a flow direction than at a downstream position in the axial direction, and a pitch of the central geometry can be greater in an upstream region than in a downstream region. In some embodiments, the inlet opening and / or the outlet opening can be arranged perpendicular to this central geometry.

[0011] The present invention is based on the idea of ​​designing a flow channel in such a way that a shortening of the length of the flow channel and thus also of the turbomachine can be provided, which implies or results in a gradient or steepness of the channel. Within the scope of the invention, a cross-sectional ratio is therefore proposed, particularly within predetermined limits, which enables a deceleration of the gas flow while simultaneously avoiding flow separation and the associated flow losses in the flow channel.

[0012] For this purpose, a length ratio of the flow channel is determined or specified, which is defined as the ratio of the axial length and the radial height of the flow channel, and a cross-sectional ratio, which is defined as the ratio of the cross-section of the inlet opening and the cross-section of the outlet opening. The axial length and the radial height of the flow channel are determined by two points on the flow channel. The first point is the intersection point of the inlet opening with the center geometry of the flow channel, and the second point is the intersection point of the outlet opening with the center geometry of the flow channel. The axial length extends in the axial direction from the first point to the second point, and the radial height of the flow channel extends in the radial direction from the first point to the second point.The cross-section of the inlet opening and the cross-section of the outlet opening are each defined in particular by an annular surface, which is radially bounded by the inner and outer lateral surfaces of the flow channel. The central geometry of the flow channel extends between the guide vanes of the turbomachine arranged upstream and downstream of the flow channel, with each point of the central geometry being located on a normal, i.e., perpendicular to the central geometry, centrally between the two lateral surfaces of the flow channel.

[0013] If the length ratio and the cross-sectional ratio are within the proposed range, a geometry for the flow channel can be achieved which, on the one hand, allows a reduction of the axial length of the flow channel and, on the other hand, can cause a, in particular appropriate, deceleration of the gas flow, in particular in order to avoid a (near) separation of the gas flow in the flow channel and the resulting flow losses.

[0014] In one embodiment, the proposed range of cross-sectional and length ratio has a first range whose length ratio lies between approximately 0.9 and approximately 1.1 and a second range whose length ratio has a value between approximately 1.2 and approximately 1.5. The length ratio of the axial length and the radial height and the cross-sectional ratio of the cross section of the inlet opening and the cross section of the outlet opening lie either in the first mentioned range or in the second mentioned range. These two ranges can be used to define a length ratio for the flow channel which, in particular in conjunction with a suitable cross-sectional ratio described below, enables favorable flow guidance or axial length.

[0015] In some embodiments, the first region has an aspect ratio between about 1.05 and about 1.19, in particular between about 1.05 and about 1.11 or between about 1.11 and about 1.19. In some embodiments, the second region has an aspect ratio between about 1.02 and about 1.16, in particular between about 1.02 and about 1.10 and / or between about 1.10 and about 1.16. This allows a suitable delay for the gas flow within the flow channel to be determined according to its aspect ratio.

[0016] In some embodiments, the first region has an aspect ratio between approximately 0.9 and approximately 1.05, in particular between approximately 0.95 and approximately 1.0 and / or between approximately 1.0 and approximately 1.1. In some embodiments, the second region has an aspect ratio between approximately 1.23 and approximately 1.45, in particular between approximately 1.23 and approximately 1.3 and / or between approximately 1.3 and approximately 1.45. As a result, the aspect ratio can be selected such that a suitable axial length is obtained for the respective application area of ​​the flow channel.

[0017] Further features, advantages, and possible applications of the invention will become apparent from the following description in conjunction with the figures. In general, features of the various exemplary aspects and / or embodiments described herein can be combined with one another, unless this is clearly excluded in the context of the disclosure. In particular, the ratios stated herein do not represent hard limits, below or above which the advantages of the invention could no longer be achieved. Rather, the advantages achievable outside these limits are smaller. The stated values ​​define particularly suitable ranges, the disclosed marginal values ​​of which are not excluded within the context of the statement "between two values," but are to be understood as part of the defined range.

[0018] In the following part of the description, reference is made to the figures shown to illustrate specific aspects and embodiments of the present invention. It is understood that other aspects may be utilized and structural or logical changes to the illustrated embodiments are possible without departing from the scope of the present invention. The following description of the figures is therefore not to be understood as limiting. It shows Fig. 1 shows a schematic exemplary representation of an exemplary turbomachine with a flow channel according to the present disclosure; Fig. 2 shows a schematic exemplary representation of a section of an exemplary turbomachine with a flow channel according to the present disclosure; and Fig. 3 shows a schematic diagram of a cross-sectional ratio and a length ratio for a flow channel of an exemplary turbomachine according to the present disclosure.

[0019] Fig. 1 shows an exemplary schematic exemplary representation of an embodiment of a turbomachine 10 according to the invention in a schematic sectional view.

[0020] The exemplary turbomachine 10 is designed as a geared turbofan engine, as used in aircraft. Along a rotational axis X, the turbomachine 10 comprises a fan 110 with at least one fan stage, a compressor 120, a combustion chamber 130, a turbine 140, and an exhaust nozzle 150, arranged one behind the other in the flow direction R. The compressor 120 comprises a low-pressure compressor 12 and a high-pressure compressor 13, arranged one behind the other in the flow direction R. The turbine 140 comprises a high-pressure turbine 141 and a low-pressure turbine 142, arranged one behind the other in the flow direction R.

[0021] The low-pressure compressor 12 is configured to compress a gas flow drawn in by the fan 110 before it enters the high-pressure compressor 13, where further compression can occur. An exemplary flow channel 11 is formed between the low-pressure compressor 12 and the high-pressure compressor 13, which is described in more detail below.

[0022] The compressed air or gas flow exiting the high-pressure compressor 13 is directed into the combustion chamber 130, where it is combined with fuel for combustion. The hot combustion gases are expanded in the high-pressure turbine 141 and the low-pressure turbine 142 before exiting through the exhaust nozzle 150, thus providing additional thrust. The high-pressure turbine 141 and the low-pressure turbine 142 can each drive the high-pressure compressor 13, the low-pressure compressor 12, and / or the fan 110 via shaft devices 160.

[0023] Fig. 2 shows a section of an exemplary turbomachine 10 according to the invention with a flow channel 11 in a schematic sectional view in a plane of the rotational axis X of the turbomachine 10.

[0024] The flow channel 11 of the illustrated embodiment is arranged between a low-pressure compressor 12 and a high-pressure compressor 13 of a compressor of the turbomachine 10 and is designed to connect them so that a gas flow G can flow through them. An annular inlet opening 31 and an annular outlet opening 41 of the flow channel 11 are connected by means of an inner circumferential surface 24 and an outer circumferential surface 25. The inlet opening 31 and the outlet opening 41 each have a cross-section A 1 , A 2 or a cross-sectional area, which is delimited by the inner circumferential surface 24 and the outer circumferential surface 25, respectively.

[0025] A plurality of radially extending struts 21 are arranged in the flow channel 11, distributed in the circumferential direction, one of these struts 21 being shown in the sectional plane. A leading edge 21a of the strut 21 is arranged at a distance D 1 from a trailing edge 22b of an upstream guide vane 22 of the low-pressure compressor 12, also shown in the sectional plane. A trailing edge 21b of the strut 21 is arranged at a distance D 2 from a leading edge 23a of a downstream guide vane 23 of the high-pressure compressor 13, also shown in the sectional plane.

[0026] The inlet opening 31 is arranged at half the distance D 1 between the leading edge 21a of the strut 21 and the trailing edge 22b of the guide vane 22 of the low-pressure compressor 12 and the outlet opening 41 of the flow channel 11 is arranged at half the distance D 2 between the trailing edge 21b of the strut 21 and the leading edge 23a of the guide vane 23 of the high-pressure compressor 13.

[0027] A central geometry 15 of the flow channel 11 extends between the guide vanes 22, 23, with each point of the central geometry 15 being arranged at an equal radial distance from the inner and outer lateral surfaces 24, 25. The inlet opening 31 and the outlet opening 41 are arranged perpendicular to this central geometry 15.

[0028] Relative to the rotational axis X of the turbomachine 10, an axial length l of the flow channel 11 extends from an intersection point S 1 of the inlet opening 31 with the central geometry 15 in the axial direction to an intersection point S 2 of the outlet opening 41 with the central geometry 15. A radial height h of the flow channel 11 extends from the intersection point S 1 of the inlet opening 31 with the central geometry 15 in the radial direction to an intersection point S 2 of the outlet opening 41 with the central geometry 15.

[0029] Fig. 3 shows a schematic diagram 50 of a cross-sectional ratio A and a length ratio L for the flow channel 11 of the exemplary turbomachine 10 from Fig. 2 .

[0030] The length ratio L of the flow channel 11 is determined from a ratio of the axial length l and the radial height h (L=l / h), and the cross-sectional ratio A is determined from a ratio of the cross-section A 1 of the inlet opening 31 and the cross-section A 2 of the outlet opening 41 (A=A 1 / A 2 ). For a flow channel 11 of the present disclosure, the length ratio L and the cross-sectional ratio A lie in a range B that has a cross-sectional ratio A between 1 and 1.2 and a length ratio L between 0.9 and 1.5.

[0031] According to some embodiments, the region B has a first region B 1 and a second region B 2 , wherein the length ratio L of the axial length l and the radial height h and the cross-sectional ratio A of the cross section A 1 of the inlet opening 31 and the cross section A 2 of the outlet opening 41 lie either in the first region B 1 or in the second mentioned region B 2 . The length ratio L of the first region B 1 can be between 0.9 and 1.1, between 0.95 and 1.05, between 0.9 and 1.0 or between 1.0 and 1.1. The cross-sectional ratio A of the first region B 1 can be between 1.05 and 1.19, between 1.05 and 1.11 or between 1.11 and 1.19.

[0032] The aspect ratio L of the second region B 2 can be between 1.2 and 1.5, between 1.23 and 1.45, between 1.23 and 1.45, between 1.23 and 1.3, or between 1.3 and 1.45. The cross-sectional ratio A of the second region B 2 can be between 1.02 and 1.16, between 1.02 and 1.10, or between 1.10 and 1.16.

[0033] By such combinations for length ratio L and cross-sectional ratio A, a flow channel 11 can be provided which enables a favorable interaction of a flow channel gradient and a gas flow delay in order to improve an efficiency of the turbomachine 11. LIST OF REFERENCE SYMBOLS

[0034] 10 Turbomachine 11 Flow channel 12 Low-pressure compressor 13 High-pressure compressor 15 Center geometry 21 Strut 21a Leading edge of a strut 21b Trailing edge of a strut 22 Guide vane 22b Trailing edge of a guide vane 23 Guide vane 23a Leading edge of a guide vane 24 Inner surface 25 Outer surface 31 Inlet opening 41 Outlet opening 50 Diagram 110 Fan 120 Compressor 130 Combustion chamber 140 Turbine 150 Outlet nozzle 160 Shaft devices l Axial length of the flow channel h Radial height of the flow channel A Cross-sectional ratio A 1 Cross-section of the inlet opening A 2 Cross-section of the outlet opening B Area B 1 First area B 2 Second area D 1 Distance D 2 Distance G Gas flow L Length ratio R Flow direction S 1 , S 2 Intersection points X Axis of rotation of the turbomachine

Claims

1. Turbomachine (10) with a flow channel (11), which is arranged in particular between two compressors, with an annular inlet opening (31) and an annular outlet opening (41), wherein the inlet opening (31) and the outlet opening (41) are connected by means of an inner and an outer circumferential surface (24, 25) which radially delimit the flow channel (11), wherein the flow channel (11) has a plurality of radially extending struts (21) distributed in the circumferential direction, the leading edges (21a) of which are arranged at a distance (D1) from trailing edges (22b) of upstream guide vanes (22) and the trailing edges (21b) of which are arranged at a distance (D2) from leading edges (23a) of downstream guide vanes (23), wherein the inlet opening (31) and the outlet opening (41) of the flow channel (11) each at half the distance (D1, D2) between the front and rear.Trailing edges (21a, 21b) of the struts (21) and the leading and trailing edges (23a, 22b) of the adjacent guide vanes (22, 23) are arranged along a central geometry (15) extending between the guide vanes (22, 23), wherein each point of the central geometry (15) is arranged at an equal distance from the inner and outer lateral surfaces (24, 25) in a direction perpendicular thereto, and an axial length (l) of the flow channel (11) relative to the axis of rotation of the turbomachine (10) extends from an intersection point (S1) of the inlet opening (31) with the central geometry (15) in the axial direction to an intersection point (S2) of the outlet opening (41) with the central geometry (15), and a radial height (h) of the flow channel (11) from the intersection point (S1) of the inlet opening (31) with the central geometry (15) extends in the radial direction to an intersection point (S2) of the outlet opening (41) with the central geometry (15), . characterized in thata length ratio (L) of the axial length (l) and the radial height (h) and a cross-sectional ratio (A) of the cross-section (A1) of the inlet opening and the cross-section (A2) of the outlet opening lies in a range (B) which has a cross-sectional ratio (A) between 1 and 1.2 and a length ratio (L) between 0.9 and 1.

5.

2. Turbomachine (10) according to claim 1, wherein the region (B) has a first region (B1) whose aspect ratio (L) is between 0.9 and 1.1 and a second region (B2) whose aspect ratio (L) is between 1.2 and 1.5 and a aspect ratio (L) of the axial length (l) and the radial height (h) and a cross-sectional ratio (A) of the cross section (A1) of the inlet opening and the cross section (A2) of the outlet opening in the first region (B1) or in the second region (B2).

3. Turbomachine (10) according to claim 2, wherein the first region (B1) has a cross-sectional ratio (A) between 1.05 and 1.

19.

4. Turbomachine (10) according to at least one of claims 2 or 3, wherein the first region (B1) has a cross-sectional ratio (A) between 1.05 and 1.

11.

5. Turbomachine (10) according to at least one of claims 2 or 3, wherein the first region (B1) has a cross-sectional ratio (A) between 1.11 and 1.

19.

6. Turbomachine (10) according to at least one of claims 2 to 5, wherein the first region (B1) has an aspect ratio (L) between 0.9 and 1.

05.

7. Turbomachine (10) according to at least one of claims 2 to 6, wherein the first region (B1) has an aspect ratio (L) between 0.95 and 1.

0.

8. Turbomachine according to at least one of claims 2 to 6, wherein the first region (B1) has an aspect ratio (L) between 1.0 and 1.

1.

9. Turbomachine (10) according to at least one of claims 2 to 8, wherein the second region (B2) has a cross-sectional ratio (A) between 1.02 and 1.

16.

10. Turbomachine (10) according to at least one of claims 2 to 9, wherein the second region (B2) has a cross-sectional ratio (A) between 1.02 and 1.

10.

11. Turbomachine (10) according to at least one of claims 2 to 9, wherein the second region (B2) has a cross-sectional ratio (A) between 1.10 and 1.

16.

12. Turbomachine (10) according to at least one of claims 2 to 11, wherein the second region (B2) has an aspect ratio (L) between 1.23 and 1.45, preferably between 1.23 and 1.

3.

13. Turbomachine (10) according to at least one of claims 2 to 12, wherein the second region (B2) has an aspect ratio (L) between 1.3 and 1.

45.

14. Turbomachine (10) according to at least one of the preceding claims, wherein the flow channel (11) is designed to connect at least two components (12, 13) of a turbomachine (10) through which a gas flow (G) can flow.

15. Turbomachine (10) according to at least one of the preceding claims, wherein the inlet opening (31) is arranged perpendicular to the central geometry (15).

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