Flow control device for a turbomachine

Abstract

A flow guide device (1) with at least one base body (3), wherein the base body (3) extends along a longitudinal axis (L), wherein the base body (3) has at least one flow channel (6) on a base body circumference (5), wherein the flow channel (6) is delimited in its extension by a base body lateral surface (12) and by two mutually facing surfaces (10, 11), wherein the surfaces (10, 11) are inclined relative to the longitudinal axis (L) of the base body (3), wherein the base body lateral surface (12) is designed such that the two mutually facing surfaces (10, 11) have a different surface height (H) in at least one blade sectional plane (S), and wherein the longitudinal axis (L) is a plane normal to the blade sectional plane (S), characterized in that the base body lateral surface (12) has at least two sections (12a, 12b, 12c) with different surface shapes along its length,and that the main body surface (12) of an upstream section (12b) is aligned substantially tangentially to the main body surface (12) of a downstream section (12c) at least in a section transition (13) arranged between the two sections (12b, 12c).

Description

[0001] The invention relates to a flow-guiding device according to the preamble of claim 1, for example, a flow-guiding device for a turbomachine, in particular a steam turbine. The flow-guiding device has at least one base body. The base body extends along a longitudinal axis L. The base body has at least one flow channel on a base body circumference. The flow channel is delimited in its extent, in particular between a flow inlet and a flow outlet, by a base body lateral surface and by two mutually facing surfaces.

[0002] Flow guiding devices, particularly for turbomachines, are known in the prior art in a variety of designs. In a turbomachine, energy is transferred between a fluid and the components of the turbomachine in an open space by a flow according to the laws of fluid dynamics. Flow guiding devices are, for example, guide vanes or impellers of a turbine, which have at least one flow channel or a plurality of flow channels for interacting with the flow on the circumference of a base body.

[0003] DE 10 2015 224 420 A1 discloses a blade ring for a gas turbine, in particular an aircraft gas turbine, having a plurality of blades arranged side by side in the circumferential direction. The blades have a flow section extending substantially in the radial direction and having a convex suction side, a concave pressure side, a leading edge, and a trailing edge. The suction side and the pressure side are connected to one another by the leading edge and the trailing edge, wherein the blades merge radially inward and / or radially outward into an annular section of the blade ring. The annular section is designed as a contoured surface with different heights in the radial direction, wherein the annular section has a highest surface section and a lowest surface section.

[0004] US 2,918,254 A discloses various embodiments of flow guiding devices. The embodiments pursue different approaches for varying the surface height of the blades relative to a base of the flow channel between the blades. Depending on the embodiment, the blades are angled relative to the longitudinal axis or aligned parallel to it.

[0005] DE 28 24 282 A1 describes a flow guide arrangement for an axial-flow machine. Furthermore, DE 28 24 282 A1 discloses an impeller blade provided with such a flow guide arrangement. To reduce air resistance, DE 28 24 282 A1 proposes, among other things, that each impeller blade have a plate-shaped section. The platform section, in turn, has two planar surfaces.

[0006] When reducing a high enthalpy gradient, especially in single-stage turbomachines, a Laval nozzle profile is typically used as the profile for the flow channel(s). The Laval nozzle profile exhibits a convergent-divergent curve with respect to a smallest cross-section.

[0007] Particularly when the flow channel is arranged on the outer circumference of a base body and when the base body of the flow guide device has a very small diameter, the flow in the flow channel comes into contact with a strongly curved surface of the base body and thus experiences strong acceleration along the course of the flow channel. However, this acceleration only occurs on one side. Due to the partially high velocity, the flow at the outlet of the flow channel is highly inhomogeneous.

[0008] Due to this flow inhomogeneity, the flow channel, e.g., with the profile of a Laval nozzle, cannot be operated at the optimal design pressure ratio. This leads to losses, resulting in reduced efficiency. Furthermore, certain flow channel geometries that correspond to an optimal design can only be manufactured with considerable effort and thus high costs.

[0009] The present invention is therefore based on the object of specifying a flow guiding device, in particular for a turbomachine, in which an increased efficiency is achieved while at the same time being cost-effective to manufacture.

[0010] The above-mentioned object is achieved in a generic flow guide device with the features of the characterizing part of claim 1, namely in that the base body surface has at least two sections with different surface shapes in its course, and in that the base body surface of an upstream section is aligned substantially tangentially to the base body surface of a downstream section at least in a section transition arranged between the two sections.

[0011] The following explanations of preferred embodiments primarily relate to the use of the flow guide device in the expansion of a fluid. When using or considering the flow guide device in the context of a compressor, the explanations, particularly with regard to the use of the terms "flow channel inlet" and "flow channel outlet" as well as "upstream" and "downstream," are to be interpreted and understood in reverse.

[0012] The flow guide device is designed, for example, as a guide wheel for a turbomachine, such as a steam turbine. The flow guide device can be arranged, for example, as a stationary component in a turbomachine. Preferably, a plurality of flow guide devices are arranged in a multi-stage turbomachine. The flow guide device is mounted, preferably in a rotationally fixed manner, with its base body, which is designed, for example, as a hub, in a housing of the turbomachine. The base body has, in particular, a recess for a rotating shaft passing through the base body.

[0013] Furthermore, it is provided that the flow guide device is designed, for example, as the impeller of a turbomachine. The flow guide device is then attached to a rotating shaft with the base body.

[0014] Furthermore, the flow guide device is intended for use in steam jet refrigeration machines, compressors, gas turbines or engines, in particular aircraft turbines, ORC turbines, hydrogen turbines or hydrogen compressors. The flow guide device is preferably designed for operation with liquid and / or gaseous fluids, in particular water vapor, CO 2 , hydrogen, organic media, silicone oils, refrigerants.

[0015] The flow guiding device has at least one base body, in particular one which is disk-shaped or ring-shaped. The base body circumference is, for example, circular or polygonal. At least one flow channel is formed on or in the base body circumference, which extends, for example, from an upstream side of the base body, in particular with portions parallel to the longitudinal axis L, to an downstream side of the base body. The remaining base body circumference is blocked, for example by at least one blocking section, in particular of the base body, to the passage of a flow medium - in the assembled state. The upstream side and the downstream side of the base body preferably extend parallel to one another.

[0016] The flow channel is delimited in its extension between a flow inlet and a flow outlet at its base by a base body surface and on both sides by two mutually facing surfaces - the pressure-side surface and the suction-side surface. In the assembled state, the flow channel is completely closed and is further delimited, in particular radially opposite the base body surface, by at least one cover ring, inner ring or housing. If the flow channel is delimited in the direction of the base body, for example by a surface of another component, such as a blade in the case of composite blade rings, the area oriented in the direction of the base body is equal to the base body surface.

[0017] If the base body is designed as a hub, for example, the at least one flow channel is arranged on the base body circumference, which is designed as the outer circumference. If the base body is designed as an annular one, for example, the at least one flow channel is arranged on a base body circumference, which is designed as the inner circumference. In the annular design of the base body, the at least one flow channel is delimited by an inner disk.

[0018] It is further provided that a plurality of flow channels are formed on the periphery of the base body. For example, the flow channels are distributed evenly or asymmetrically around the periphery of the base body.

[0019] The flow channel cross-section, in particular the shape of the flow channel cross-section, is influenced by the base body surface, in particular the shape and orientation of the base body surface. The flow channel cross-section is, for example, constant or varies between the flow inlet and flow outlet. Advantageously, the flow channel cross-section is divergent (i.e., increasing from the flow inlet to the flow outlet), convergent (i.e., increasing from the flow inlet to the flow outlet), convergent and divergent, or has a different profile. The "cross-section" of the flow channel or "flow channel cross-section" always refers to the cross-sectional area of ​​the flow channel. If there are multiple flow channels, it is advantageous for all flow channels to be identical.

[0020] According to the invention, the main body surface in the flow channel is designed, in particular in at least one section, such that the two surfaces laterally delimiting the flow channel have a different surface height H in at least one blade section plane S. The blade section plane S is an imaginary plane to which the longitudinal axis L of the main body is a plane normal.

[0021] The main body lateral surface is preferably configured such that the surface heights H are different in at least one blade sectional plane S at at least one location along the longitudinal axis L in the section. Furthermore, it is provided that the surface heights H are different from one another in several blade sectional planes S at several locations along the longitudinal axis L of the main body. This varies the cross-section of the flow channel. The main body lateral surface is preferably configured to be uninterrupted in its course, i.e., it has no joints.

[0022] In particular, it is provided that the surface heights H in at least one blade sectional plane S have a height difference of at least 3%, in particular at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 75% or at least 90%. It is further preferably provided that in at least one first blade sectional plane S the surface heights H are different from one another at at least one first point on the longitudinal axis L in the course of the flow channel, that in at least one second blade sectional plane S the surface heights H are different from one another at at least one second point on the longitudinal axis L in the course of the flow channel, and that the surface heights H in the first blade sectional plane are greater or lesser than the surface heights in the second blade sectional plane.

[0023] Furthermore, it is provided that the surface height H of the surface arranged upstream, in particular on the pressure side, in a blade section plane S is smaller than the surface height H of the surface arranged downstream, preferably on the suction side. As a result, the main body surface is inclined in the direction of the flow outlet.

[0024] The surface height H of the respective surface - pressure-side or suction-side - is the distance swept, particularly in the blade section plane S or the flow channel section plane E, between the base body surface and the end of the surface facing away from the base body. This applies in particular to surfaces inclined towards the flow channel or away from it. Minor radii, particularly those caused by manufacturing, in the area between the base body surface and the surfaces are disregarded; larger radii are attributed to the base body surface. In the event that the surfaces are aligned radially to the longitudinal axis L of the base body, the surface height H of the surfaces corresponds to the height of the surfaces in the radial direction - the radial height.

[0025] According to the invention, different surface heights H of the surfaces in the blade section plane S can be achieved, for example, by means of a correspondingly designed shape and orientation of the base body surface - at least in one section.

[0026] In this way, an advantageous alignment of the base body surface is ensured, which reduces inhomogeneity of the flow velocity and increases efficiency.

[0027] It is further particularly preferably provided that the surface heights H of the two surfaces delimiting the flow channel in a blade sectional plane S at the flow inlet - at a point on the longitudinal axis L at the flow inlet - are the same and / or that the surface heights H of the two surfaces delimiting the flow channel in a blade sectional plane S at the flow outlet - at a point on the longitudinal axis L at the flow outlet - are the same. Furthermore, it is preferably provided that the main body lateral surface is convexly curved with a radius at least at the flow inlet and / or at least at the flow outlet. In the blade sectional plane S at the flow inlet and / or at the flow outlet, the main body lateral surface is a convexly curved line in such a configuration.

[0028] The above refinement ensures that, despite the inventive configuration of the base body surface, a "standard interface" to other components, e.g., impellers or guide vanes, is nevertheless formed at least in one section of the flow channel, at the flow inlet and / or at the flow outlet. The flow guide device according to the invention is thus readily compatible with components known from the prior art in the flow path within a machine.

[0029] According to a first, particularly preferred embodiment of the flow guiding device, the main body surface is further designed and arranged such that the surface heights H of the mutually facing surfaces in at least one flow channel sectional plane E are substantially equal, wherein the flow channel sectional plane E is oriented such that a central flow filament—according to flow filament theory—passes through the flow channel sectional plane E in the normal direction. The flow filament passes through the flow channel sectional plane E at the point along the longitudinal axis L at which the blade sectional plane S is also viewed.

[0030] In particular, it is provided that an intersection line of the flow channel intersection plane E and the blade intersection plane S intersects the flow thread of the flow channel.

[0031] The main body lateral surface is therefore designed such that, when viewed at at least one point along the longitudinal axis L of the main body in a blade section plane S, the surface heights H are different from one another, and the surface heights H in an associated flow channel section plane E - when viewed at the same point along the longitudinal axis L - are essentially the same. Due to an oblique and / or curved course of the flow channel, the surface heights H in the two planes considered relate to different areas of the surfaces in the flow channel that laterally delimit the flow channel.

[0032] The surface height H of the two surfaces bounding the flow channel is therefore essentially the same in the flow channel section plane E, whereby the flow channel section plane E is orthogonally traversed by the central streamline of the flow channel - at the same point along the longitudinal axis L of the base body in which the blade section plane S is viewed.

[0033] In particular, it is provided that the main body surface is designed in such a way that it represents a straight line, a convex line, a concave line or a line with at least one straight section and at least two convex or concave sections - curvature, in particular radii in the edge regions of the main body surface - in at least one flow channel section plane E at a location along the central flow path, preferably in a plurality of flow channel planes E along the central flow path.

[0034] A further embodiment of the flow guide device provides for at least one blade to be arranged on the periphery of the base body. Two flow channels are formed, namely between the two surfaces of the blade and one surface of each blocking section.

[0035] It is particularly preferably provided that at least two blades are arranged on the base body circumference, and that the at least one flow channel is formed between the blades. The surfaces facing one another that laterally delimit the flow channel are preferably the corresponding surfaces of the blades, i.e. the pressure-side surface of one blade and the suction-side surface of the other blade. The surface heights H then correspond to the extension of the blades in the respective plane E, S under consideration or to the radial height of the respective blade when the blades are radially aligned. According to the invention, the surface height H of one blade in the blade sectional plane S is greater or smaller than the surface height H of the other blade in the blade sectional plane. In particular, the surface height H in the associated flow channel sectional plane E is approximately the same for both blades.

[0036] Preferably, at least two additional flow channels are arranged on the periphery of the base body, each of which is delimited in particular by a blade and the base body or the at least one blocking section. For example, a flow channel is formed between a pressure-side surface of one blade and a suction-side surface of the blocking section, and between a suction-side surface of the other blade and a pressure-side surface of the blocking section.

[0037] According to a further preferred embodiment of the flow guiding device, a plurality of blades are arranged on the base body circumference—outer circumference or inner circumference. The blades are arranged, for example, distributed symmetrically or asymmetrically on the base body circumference.

[0038] In particular, each flow channel is completely closed along its course during operation. For blades arranged on an outer circumference of the base body, the base body is finally delimited by a cover ring, preferably applied, in particular shrunk onto, an outer circumference of the blades, or by a housing of the machine. For blades arranged on an inner circumference of a base body, for example, one with a ring shape, the flow channels are finally delimited, for example, by an inner disk.

[0039] A partial loading of the flow guide device is provided, in which only a certain portion of the base body circumference is provided with blades, for example, approximately 50% of the base body circumference. The base body with the plurality of blades is preferably designed for partial loading. The remaining portion of the base body circumference is closed to flow. In such embodiments, a portion of the flow channels is formed between a respective blade and a blocking section, wherein the surface of a blocking section partially delimiting a respective flow channel has the profile of a corresponding surface of a blade.

[0040] At least one flow channel is formed between each two adjacent blades, so that a plurality of flow channels are formed on the circumference of the base body. The mutually facing surfaces of the adjacent blades meet the above-described requirements with regard to the surface height H in order to design an advantageous base body surface.

[0041] If in the above or following explanations reference is made to a single flow channel between two adjacent blades, the described properties apply equally to each flow channel of each pair of blades on the circumference of the base body.

[0042] According to the invention, each flow channel has at least one section along its course in which the adjacent blades have a different surface height H in the imaginary blade sectional plane S, which corresponds in particular to the radial height of the blade. Such different heights of the blades in the blade sectional plane S can be achieved, for example, by means of a correspondingly designed surface profile of the base body lateral surface.

[0043] For radially aligned surfaces, especially blade surfaces, the surface height H is identical to the radial height. The radial height of a blade at a specific location is determined between the base body surface and the end of the blade facing away from the base body – in the radial direction, starting from the longitudinal axis L. For example, the radial height of a blade is measured from a specific point on the base body surface on a radial line starting from the longitudinal axis L of the base body.

[0044] Preferably, the two adjacently arranged blades, each delimiting a flow channel, have a varying surface height H, in particular radial height H, along the flow channel. Consequently, the surface height H of the blades varies along the extent of the flow channel, viewed in a plurality of flow channel sectional planes E, each of which is aligned such that the central flow thread passes through the respective flow channel sectional plane E as a plane normal. The surface height H of the two blades is preferably the same in each individual blade sectional plane E.

[0045] The surface height H of the blades varies identically for both blades along the flow channel, in particular in the respective flow channel sectional plane E under consideration. It is also provided that the surface heights H of the two mutually facing surfaces, in particular of the blades, differ from one another in at least one flow channel sectional plane S along the flow channel.

[0046] By varying the surface heights H of the blades along the flow channel, with the boundary condition of different surface heights H in at least one blade section plane S along the flow channel, advantageous cross-sectional shapes for the flow channel can be designed, in particular in at least one section, which increase the efficiency.

[0047] Depending on the use of the flow guiding device, it is intended that the cross-section of the flow channel is constant over the course of the flow channel - despite the change in the surface height H of the blades - or that the cross-section varies over the course of the flow channel.

[0048] For example, it is provided that the cross section of the flow channels, i.e. of each individual flow channel, is varied at least in sections by a changing surface height H of at least one of the blades laterally delimiting the flow channel, in particular a changing surface height H of both blades laterally delimiting the flow channel.

[0049] In particular, it is provided that the end regions or the ends of all blades lie on a common diameter, in particular a common outer diameter, for example in the case of a disk-shaped base body, or a common inner diameter, for example in the case of an annular base body, and inwardly directed blades. It is provided that the entire end surface of each blade lies on a single diameter, or that - for example in the case of blades that change their outer diameter along the course of the flow channel - at least the end of each blade furthest from the base body lies on a common diameter.

[0050] Furthermore, it is provided that the surface heights H of the two blades delimiting the flow channel in a blade sectional plane S at the flow inlet - at a point on the longitudinal axis L at the flow inlet - are the same and / or that the surface heights H of the two blades delimiting the flow channel in a blade sectional plane S at the flow outlet - at a point on the longitudinal axis L at the flow outlet - are the same. The flow inlet preferably extends between the respective leading edges of the blades, the flow outlet between the trailing edges of the two blades. In particular, the leading edges of the two blades lie on a common first diameter and / or the trailing edges of the two blades lie on a common second diameter. The second diameter is preferably smaller than the first diameter.

[0051] Furthermore, it is preferably provided that the main body surface is convexly curved with a radius at least at the flow inlet and / or at least at the flow outlet. In the blade sectional plane S at the flow inlet and / or at the flow outlet, the main body surface in such a configuration is a convexly curved line between the two blades.

[0052] In particular, trailing edges with identical surface heights H in combination with a circularly curved base body surface at the flow outlet, particularly in a section upstream of the flow outlet, allow the flow to optimally exit the flow guide device and, if necessary, flow to a subsequent impeller. Corresponding advantages are realized by leading edges with identical surface heights H in combination with a circularly curved base body surface at the flow inlet. This design achieves increased efficiency.

[0053] The flow guiding device is preferably designed for flow against the blades in a direction substantially parallel to a longitudinal axis of the base body. In particular, it is provided that the flow against the flow guiding device is such that the meridional component of the flow velocity is parallel to the longitudinal axis L. It is also provided that the flow against the blades is swirled. The flow guiding device is intended in particular for an axial machine. In a design as a stator, the longitudinal axis L of the base body coincides with the axis of rotation of a shaft, preferably passing through the base body. In a design as an impeller, the flow guiding device rotates about the longitudinal axis L.

[0054] According to the inventive design of the flow guide device, the base body surface has at least two sections with different surface shapes along its course in the flow channel. The surface shapes in the at least two sections differ from one another, so that the base body surface is, for example, flat in at least one section and curved with a radius in at least one further section.

[0055] For example, the base body surface has at least three, at least four, or at least five different sections along its course along the flow channel. Preferably, the surface shape in each section differs from each subsequent section. However, it is also possible for only the surface shape of each subsequent section in the flow direction to differ from the preceding section.

[0056] In particular, according to a further development, the surface shape of at least one section of the main body's lateral surface is designed differently from a surface shape of the main body upstream and / or downstream of the flow channel, i.e., before the flow inlet and / or after the flow outlet. For example, the surface shape of the main body upstream and downstream of the flow channel is circular with a radius, wherein the radius upstream of the flow channel is preferably larger than the radius downstream of the flow channel. The surface shape of at least one section of the main body's lateral surface within the flow channel is, for example, either curved with a different radius than upstream and downstream of the flow channel or is designed, for example, as a flat surface.In particular, it is provided that the first section of the main body surface behind the flow inlet is convexly curved with a single, first radius and / or that the last section of the main body surface before the flow outlet is convexly curved with a single, second radius. The first radius and the second radius are different from one another; in particular, the second radius is smaller than the first radius.

[0057] According to the invention, the main body surface of an upstream section is oriented substantially tangentially to the main body surface of a downstream section at least in at least one section transition located between the two sections. The gradient of the two sections is identical, at least in the section transition.

[0058] For example, it is provided that the section of the base body's lateral surface closest to the flow outlet is curved with a radius. The radius preferably corresponds to the radius of the base body at the flow outlet. The section arranged upstream in the flow channel, which is designed, for example, as a flat surface or a concave surface, is aligned tangentially to the curved surface of the downstream section at the section transition.

[0059] However, it has also been shown that acceptable flow characteristics can be achieved when the main body surface is only essentially tangential, i.e., approximately tangential. For example, deviations of ± 15%, especially ± 5%, are acceptable.

[0060] With this design of the main body surface, a continuous, jump-free transfer of the flow into the subsequent section, in particular the last section, of the main body surface before the flow outlet is advantageously realized.

[0061] Furthermore, it is preferably provided that at least two sections of the main body surface are configured and aligned with each other in such a way that a Prandtl-Meyer expansion is ensured at the section transition. This preferably involves the section of the main body surface arranged closest to the flow outlet and the section arranged upstream thereof.

[0062] With regard to the efficiency, advantageous results can be achieved within the framework of a further embodiment of the flow guiding device by providing that the flow channel, in particular each flow channel, has a smallest cross-section along its course.

[0063] Advantageously, the cross-sectional profile of each flow channel has the profile of a Laval nozzle. Starting at the flow inlet of the flow channels, the cross-section decreases until reaching a smallest cross-section of the flow channels. From this smallest cross-section, the cross-section increases continuously again until reaching a flow outlet, thus creating a Laval nozzle for the flow. The cross-section is thus converging up to the smallest cross-section and diverging from the smallest cross-section onwards. The fluid can thus be accelerated to supersonic speeds without the occurrence of shock waves.

[0064] Preferably, the cross-section of the flow channels decreases starting from an inlet cross-section at the beginning of the flow channels, in particular continuously, down to a smallest cross-section and decreases again from - i.e. downstream - the minimum cross-section, in particular continuously up to an outlet cross-section of the flow channels.

[0065] By changing the surface height H of the blades, for example, the cross-section of the flow channels can be varied only by changing the cross-sectional height H of the blades, in particular by changing the surface area of ​​the main body, while maintaining a constant distance between the two adjacent blades. For example, the surface height H of the blades—viewed in flow channel sectional planes E—decreases down to the smallest cross-section and then continuously increases again from there. To change the surface height H of the adjacent blades, the profile of the main body's surface area is advantageously adjusted.

[0066] Particularly preferably, the cross-section of the flow channels is varied both by means of the distance between the mutually facing surfaces of the adjacent blades, in particular orthogonal to the flow direction, and by means of the surface height H of the blades. The cross-sectional profile of each flow channel between two blades is thus varied via two degrees of freedom, i.e., both by means of the distance between two mutually facing surfaces of the blades and by means of the surface height H of the blades.

[0067] Furthermore, up to the smallest cross-section, the cross-section is preferably changed solely by changing the distance and shape of the facing surfaces of the two adjacent blades. The surface height H of the blades - viewed in the flow channel section plane E - is constant up to the smallest cross-section of the flow channel. From the smallest cross-section onwards, the cross-section is achieved both by increasing the distance or shape of the facing surfaces of the blades, as well as by continuously increasing the surface height H of the blades - viewed in blade section planes E. With flow channels that are each designed as a Laval nozzle, optimal results in terms of efficiency can be achieved.

[0068] It is also provided that the smallest cross-section is located at the flow inlet, and the cross-section increases from there along the flow channel. Furthermore, it is provided that the smallest cross-section is located at the flow outlet.

[0069] This design has the advantage over the prior art that the generation of a minimum cross-sectional area in each flow channel between two adjacent blades no longer depends solely on the distance between the two blades, but can also be influenced by the shape of the base body's lateral surface. Despite a larger distance between the surfaces of the adjacent blades, smaller cross-sectional areas can be achieved for the minimum cross-section, for example, by locally reducing the surface height H, in particular the radial height, of the blades.

[0070] When milling from solid material, for example, the minimum diameter of the milling head is no longer the limiting factor for achieving the smallest possible cross-section of the flow channel, since the cross-sectional area can also be achieved by reducing the penetration depth of the milling head. This advantageous flow guidance device can thus be manufactured cost-effectively.

[0071] With the above designs, a variety of characteristic cross-sectional area profiles of the flow channels can be constructed in order to operate the flow channels as closely as possible to the design parameters and to increase the efficiency.

[0072] In particular in order to vary the surface height H of the blades in the course of the flow channel, it is provided according to a further embodiment that the main body surface in the flow channel, in particular in at least one section of the main body surface, is at least partially flat and / or concave and / or convex.

[0073] For example, the base body's lateral surface has at least one convex section and / or at least one concave section and / or at least one flat section in its course between the flow inlet and flow outlet. In an arrangement of convex and concave sections, the course of the base body's lateral surface is spline-shaped.

[0074] Preferably, the convex and / or concave curvature of the main body surface extends only in the direction of flow. Furthermore, it is also provided that the convex and concave curvature of the main body surface extends both in the direction of flow and orthogonally thereto. The main body surface then has, for example, a shape curved in two directions.

[0075] Furthermore, it is provided that at least one flat section of the main body surface is arranged inclined in the flow direction and / or transversely to the flow direction. If the main body surface is designed as a flat surface with an incline in one section, this section bridges, for example, the difference between the larger diameter of the main body at the smallest cross-section of the flow channel and a smaller diameter at the flow outlet of the flow channel. The main body surface is in particular designed like a ramp. To bridge this difference, the section is aligned at an incline. It is also provided that the main body surface is designed to be concave and / or convex at least in sections, in particular completely, along the course of the flow channels.Particularly preferably, a concave base body surface is arranged between the smallest cross-section and a section transition to the last section before the flow outlet.

[0076] It is intended that the surface of the base body is completely continuous along the flow channel or has at least one discontinuity, in particular at least two discontinuities.

[0077] For example, it is provided that the main body surface downstream and / or upstream of the smallest cross-section is at least partially flat and / or concave and / or convex. Particularly preferably, the main body surface downstream of the smallest cross-section initially has a convex section—particularly in the flow direction—followed by a concave or flat section, and finally by a convex section with a radius.

[0078] According to a further embodiment, it has proven advantageous if the surface height H of the blades at the flow inlet and / or at the smallest cross-section is smaller than the surface height H of the blades at the flow outlet. In this embodiment, the cross-section of the flow channel is preferably varied substantially via the surface height H of the blades along the course of the flow channel.

[0079] Furthermore, it is also provided that the surface height H of the blades at the flow inlet and / or at the smallest cross-section is greater than the surface height H of the blades at the flow outlet.

[0080] A further embodiment provides that the surface height H of the blades increases, starting from the smallest cross section, in the direction of the flow outlet and / or the flow outlet of the flow channels. The surface height of the blades increases continuously or discontinuously along the flow channel, starting from the smallest cross section in the direction of the flow outlet and / or the flow inlet.

[0081] A further embodiment of the flow guiding device provides that at least one surface of the two mutually facing surfaces, in particular of the adjacent blades upstream and / or downstream of the smallest cross section of the flow channels, is at least partially, in particular completely, flat and / or convex and / or concave. The two mutually facing surfaces of the blades delimiting the flow channel are, for example, the surface on the suction side of a first blade and the surface on the pressure side of a second blade. It is preferably provided that both mutually facing surfaces of the adjacent blades upstream and / or downstream of a smallest cross section of the flow channels in the flow direction are at least partially, in particular completely, flat and / or concave and / or convex.

[0082] If one of the surfaces is both partially convex and partially concave, it has a spline configuration. For example, at least one of the surfaces is convex and / or concave in the flow direction, or at least one of the two surfaces is convex and / or concave both in the flow direction and orthogonally thereto.

[0083] In particular, it is provided that the mutually facing surfaces of the adjacent blades are completely flat in the flow direction behind the narrowest cross-section of the flow channels. Downstream of the point with the narrowest cross-section, both mutually facing surfaces of the adjacent blades are designed as completely flat surfaces. The two surfaces are preferably arranged diverging from one another, i.e., their distance increases with the length of the flow channel, i.e., in the direction of the flow outlet. This flat design allows the blades to be manufactured easily.

[0084] In particular, the surface on the suction side of a first blade behind the smallest cross section is completely flat and the surface on the pressure side of a second blade behind the smallest cross section is completely flat.

[0085] Furthermore, it is provided, for example, that the mutually facing surfaces, in particular of the adjacent blades, are convex or concave in the flow direction upstream of a narrowest cross-section of the flow channels. Preferably, one of the surfaces is convex and one of the surfaces is concave. The blades are angled relative to the longitudinal axis of the base body, so that each blade has a deflection surface - in particular on the pressure side - for the flow. Preferably, the deflection surface is concave, and the opposite - rear side - of the adjacent blade - in particular the suction side - is convex. The deflection surface is preferably concave up to the narrowest cross-section of the flow channel.

[0086] With this embodiment, particularly together with the simultaneous variation of the height of the blades, in particular via the shape and the profile of the main body surface, advantageous cross-sectional profiles for the flow channels can be designed in order to increase the efficiency.

[0087] A further embodiment of the flow guiding device provides that a diameter of the base body upstream of the flow channel, in particular of the flow channels, is larger than the diameter of the base body downstream of the flow channel, or vice versa. In particular, it is provided that the diameter of the base body, in particular viewed in the flow direction, upstream of the flow channel is larger than the diameter of the base body, in particular viewed in the flow direction, downstream of the flow channel. For example, the base body has the largest diameter at the flow inlet of the flow channel and the smallest diameter at the flow outlet of the flow channel.

[0088] The flow channel, in particular the main body surface and the surface height H of the blades, is designed such that the difference in diameter is bridged. It is preferably provided that the diameter of the main body in the flow channel is constant up to a point with the smallest cross-section of the flow channel. Consequently, the main body surface has a shape, for example up to the smallest cross-section, that corresponds to the surface shape of the main body before the flow inlet. After the smallest cross-section, the main body surface has a section that is designed as a flat surface or as a concave surface. This is followed by a section that extends to the flow outlet and is convexly curved with the diameter of the main body at the flow outlet.Preferably, the diameter reduction between the diameter before the flow inlet and after the flow outlet - in particular of the last section - is about 5% to 15%, preferably about 10%.

[0089] In particular, to simplify production, a further embodiment provides for the base body and the flow channel, in particular the base body and the blades, to be formed as a single piece. The base body and the flow channel, in particular the blades, are thus formed from a single material. It is particularly advantageous for the base body and the flow channel, in particular the blades, to be formed from a solid piece by milling.

[0090] By influencing the cross-section of the flow channel via the surface height H of the blades or via the design of the base body surface, advantageous cross-sectional profiles for the flow channel can be created using a milling cutter, since the narrowest cross-section can now also be adjusted via the penetration depth - for a given milling head diameter.

[0091] Furthermore, it is envisaged that the base body and the flow channel, in particular the blades, are formed using an additive manufacturing process. Direct metal laser sintering (DMLS), electron beam melting (EBM), selective laser sintering (SLS), selective laser melting (SLM), metal binder jetting, and nanoparticle jetting have proven particularly advantageous processes. Using additive manufacturing processes, advantageous cross-sectional shapes of the flow channel can be realized, particularly with undercuts, for example.

[0092] A flow guiding device according to the invention can also be described as follows: Flow guiding device, in particular for a turbomachine, comprising at least one base body and a plurality of blades, wherein the blades are arranged distributed over a circumference on the base body, wherein at least one flow channel is formed between two adjacent blades, so that a plurality of flow channels are formed, wherein the flow channel has a larger diameter at the flow inlet than at the flow outlet, wherein each flow channel is delimited by a base body surface, characterized in that the base body surface is designed in a ramp-like manner in at least one section, so that the difference in diameter at the flow inlet and at the flow outlet is bridged, and in that the surface height H of the blades orthogonal to the mean flow path is the same at every point,but varies at different points. The surface height H of the blades is varied along the flow channel.

[0093] A flow guiding device according to the invention can further also be described as follows: Flow guiding device, in particular for a turbomachine, comprising at least one base body and a plurality of blades, wherein the base body extends along a longitudinal axis, wherein the blades are arranged distributed over a circumference on the base body, wherein each blade has a suction side and a pressure side, wherein at least one flow channel is formed between two adjacent blades, so that each flow channel is at least partially delimited by the suction side of a first blade and the pressure side of a second blade and a plurality of flow channels is formed, and wherein the base body delimits each flow channel in its course with a base body lateral surface, characterized in thatthat the suction side of the first blade and the pressure side of the second blade each have a varying surface height H along the course of each flow channel, and that each flow channel has at least one section in its course in which the suction side of the first blade and the pressure side of the second blade have a different surface height H in the blade section plane S, wherein the longitudinal axis is a plane normal to the blade section plane S.

[0094] A flow guiding device according to the invention can furthermore also be described as follows: Flow guiding device, in particular for a turbomachine, comprising at least one base body and a plurality of blades, wherein the blades are arranged distributed over a circumference on the base body, in particular wherein the ends of all blades facing away from the base body are arranged on a common diameter, wherein at least one flow channel is formed between two adjacent blades, so that a plurality of flow channels are formed, wherein each flow channel has a varying cross-section in its course, preferably wherein an onflow of the blades is provided with a median component of the onflow velocity parallel to a longitudinal axis of the base body, characterized in thatthat the cross-section of the flow channels is varied, at least in sections, by a changing surface height of at least one of the two adjacent blades. In particular, that the surface height H of the blades is varied equally orthogonally to the flow direction - orthogonal to the mean flow path.

[0095] The invention further relates to a turbomachine having at least one, preferably a plurality of flow guiding devices according to one of the embodiments described above.

[0096] Further advantageous embodiments of the invention emerge from the following description of the figures and the dependent subclaims.

[0097] They show: Fig. 1 an embodiment of a flow guiding device in perspective view with a view of the flow outlet, Fig. 2 the embodiment of a flow guiding device according to Fig. 1 in perspective view with view of the flow inlet, Fig. 3 a perspective view of the flow outlet of an embodiment of a flow guiding device according to Fig. 1 and Fig. 2, Fig. 4 a plan view of an embodiment of a flow guiding device according to Fig. 1 and Fig. 2, Fig. 5 an embodiment of a flow guiding device according to Fig. 1 and Fig. 2 with a view into the flow channel, starting from the flow outlet, Fig. 6 an embodiment of a flow guiding device according to Fig. 1 and Fig. 2 with a view of the flow outlet of the flow channel, Fig. 7 a section of an embodiment of a flow guiding device in a first blade cutting plane, Fig. 8 a section of the embodiment of a flow guiding device according to Fig. 7 in a second blade cutting plane, Fig. 9 a section of the embodiment of a flow guiding device according to Fig. 7 and Fig. 8 in a third blade cutting plane, Fig. 10 a section of the embodiment of a flow guiding device according to Fig. 7, Fig. 8 and Fig. 9 in a fourth blade cutting plane, Fig. 11a an embodiment of a development of a blade cross-section for a blade of a flow guiding device, and Fig. 11b an embodiment of a development of a blade cross-section for a blade of a flow guiding device.

[0098] In the various figures of the drawing, identical parts are always provided with the same reference symbols.

[0099] With regard to the description, it is claimed that the invention is not limited to the exemplary embodiments and not to all or several features of described combinations of features, but rather each individual partial feature of the / each exemplary embodiment is also detached from all other partial features described in connection therewith, in itself and also in combination with any features of another exemplary embodiment, of importance for the subject matter of the invention.

[0100] Fig. 1 to Fig. 6 show an embodiment of a flow guiding device 1 in various views and magnifications. The flow guiding device 1 has a base body 3 and a plurality of blades 4. The blades 4 are arranged evenly distributed over a base body circumference 5 of the base body 3. A flow channel 6 is laterally delimited by each two adjacent blades 4, so that a plurality of flow channels 6 are formed distributed over the circumference 5 of the base body 3. The number of flow channels 6 depends on the number of blades 4. Each flow channel 6 has a varying cross-section along its course between the flow inlet 7 and the flow outlet 2. The flow inlet 7 extends on the upstream side for each flow channel 6 between a leading edge 4a of one blade 4 and a leading edge 4a of the other blade 4 - see Fig. 2. The flow outlet 2 extends for each flow channel on the downstream side between a trailing edge 4b ​​of one blade and a trailing edge 4b ​​of the other blade 4 - Fig. 1. In this embodiment, the base body 3 is designed as a hub. An opening for the passage of a shaft is not shown.

[0101] Fig. 1 shows a view from a downstream side of the flow guide device 1 when used as a guide wheel. Fig. 2 shows the inflow side when used as a diffuser. According to Fig. 1, the ends 8 of the blades 4 facing away from the base body 3 lie on a common diameter D1. In particular, in this embodiment, the entire end 8 of each blade lies in a curved surface, each point of which lies on the common diameter D1.

[0102] In the assembled state of the flow guide device 1, a cover ring (not shown) is applied to the ends 8 of the blades 4, which delimits the flow channels 6. The base body 3 has a diameter D2 at the flow inlet 7 of the flow channels 6 - see Fig. 2 - which is about 10% larger than a diameter D3 at the flow outlet 2 - see Fig. 1.

[0103] According to Fig. 1 to Fig. 6, the course of each flow channel 6 begins between two adjacent blades 4 at the flow inlet 7 - between the leading edges 4a. The blades 4 are set at an angle of approximately 10° to the longitudinal axis L of the base body 3, so that the flow approaching the blades 4 is deflected by the flow channels 6. In this embodiment, all blades 4 and thus all flow channels 6 are identical.

[0104] According to Fig. 3, Fig. 4 and Fig. 6 is a surface H1 of the blades 4 at the flow inlet 7 is less than a surface height H 2 of the blades 4 at the flow outlet 2. The blades 4 are radially aligned so that the surface height H corresponds to the radial height. The radial height - and here also the surface height H - of the blades 4 is determined in the radial direction along a line starting from the longitudinal axis L of the base body 3 - see Fig. 1. The radial height is measured between a surface of the base body 3 along this line and the end 8 of the blades 4 facing away from the base body 3 - see Fig. 1.

[0105] According to Fig. 1 to Fig. 6, the flow channels 6 have a varying cross-section along their path between the flow inlet 7 and the flow outlet 2. The cross-section of the flow channels 6 is influenced by a varying distance between the blades 4 orthogonal to the flow direction, as well as by the changing surface height H of the blades 4 along the path of the flow channels 6. Each flow channel 6 has a smallest cross-section 9.

[0106] Each flow channel 6 is laterally delimited by the mutually facing surfaces 10, 11, namely - viewed in the flow direction - a rear surface 10 - here the suction-side surface 10 - of a blade 4 and a front surface 11 of a blade 4 - here the pressure-side surface 11. Each of the surfaces 10, 11 has at least a first surface section 10a, 11a upstream of the smallest cross-section 9 and a second surface section 10b, 11b downstream of the smallest cross-section 9.

[0107] According to Fig. 1 to Fig. 4, the first surface section 10a of the surface 10 is convex upstream of the smallest cross-section 9. The first surface section 11a of the surface 11, which faces the surface 10 to delimit the flow channel 6, is concave up to the smallest cross-section 9. The surface sections 10a, 11a are aligned converging toward one another, so that their distance decreases in the direction of the smallest cross-section 9. The surface height H 1 of the blades 4 and the diameter D2 of the base body 3 are constant up to the smallest cross section 9.

[0108] The second surface section 10b of the surface 10 downstream of the smallest cross-section 9 is completely flat. The second surface section 11b of the surface 11 downstream of the smallest cross-section 9 is also completely flat. Downstream of the smallest cross-section 9, the surface sections 10b, 11b or the surfaces 10, 11 are aligned diverging from one another, so that their distance increases in the direction of the flow outlet 2. Downstream of the smallest cross-section 9, the surface height H of the blades 4 increases continuously up to the height H 2 at the flow outlet 2. The diameter D2 of the base body 2 decreases along the flow channel 6 to the diameter D3 at the flow outlet 2.

[0109] Each flow channel 6 is delimited in its course by a base body surface 12. In the assembled state, each flow channel 6 is further delimited by a cover ring (not shown) at the end 8 of the blades 4. In the embodiment of the Fig. 1 to Fig. 6, the base body surface 12 has a first section 12a in front of the smallest cross section 9, a second section 12b behind the smallest cross section 9 and a third section 12c directly at the flow outlet 2.

[0110] The first section 12a of the base body surface 12 is convex and has the diameter D2 up to the smallest cross section 9 - see Fig. 2, Fig. 4 and Fig. 5. The second section immediately behind the smallest cross-section 9 is concave in the flow direction. The second section 12b is inclined in the flow direction and extends to a section transition 13 - see Fig. 1, Fig. 3, Fig. 5 and Fig. 6. From the section transition 13, a third section 12c of the main body surface 12 follows, which is convex and has the diameter D3 at the flow outlet 2 - see Fig. 1, Fig. 3, Fig. 5 and Fig. 6.

[0111] Due to the inclined arrangement of the main body surface 12 in the second section 12b in the flow channels 6, the surface height H of the blades 4 increases along the flow channels 6, thereby also increasing the cross-section of the flow channel 6. The flow channels 4 are designed as Laval nozzles.

[0112] Because the cross section of the flow channels 6 is changed not only in its width - the distance between the surfaces 10, 11 orthogonal to the flow direction or to the central flow thread - but also in its height - shape and course of the main body surface 12 - a variety of profile courses can be designed for the flow channel 6 and operated in the design state, so that the efficiency of the turbomachine is increased by such a flow guiding device 1.

[0113] In the embodiment of the Fig. 1 to 6, the cross-section of the flow channel 6 is rectangular at every point along its course, so that the cross-section is calculated by multiplying the surface height of the blade 4 and the distance between the surfaces 10, 11 at the respective point. In particular, in the second section 12b of the main body surface 12, the surface height H 5for the surfaces 10b, 11b in each flow channel section plane E along and orthogonal to the central streamline are essentially the same. In Fig. 6 is an example of a flow channel section plane E of many flow channel section planes E in the course of the flow channel 6 with the associated surface height H 5 shown, namely at the section transition 13 between the second section 12b and the third section 12c.

[0114] According to Fig. 1, Fig. 3, Fig. 5 and Fig. 6, the second section 12b of the main body surface 12 in the section transition 13 to the third section 12c is aligned tangentially to the main body surface 12 in the third section 12c in order to ensure optimal flow transfer. The gradient of the second section 12b of the main body surface 12 in the section transition 13 is essentially identical to the gradient of the third section 12c of the main body surface 12. The third section 12c behind the section transition 13 has a diameter D3 according to Fig. 1. The third section 12c is convex, in particular circular, between the blades 4, in particular between the trailing edges 4b of the blades 4.

[0115] The thin trailing edges 4b of the blades 4, in conjunction with the circular third section 12c of the main body surface 12 in front of the flow outlet 2, allow the flow to optimally exit the flow guide device and, if necessary, flow toward a subsequent impeller. This results in increased efficiency.

[0116] In the embodiment of the Fig. 1 to Fig. 6, the base body 3 and the blades 4 are formed as one piece, namely milled from solid material. Previously, the diameter of a milling head was the limiting factor for the distance between the surfaces 10, 11 orthogonal to the flow direction or the mean flow path at the smallest cross-section 9. Because the surface height H in the area of ​​the smallest cross-section 9 can now also be influenced according to the invention, smaller cross-sections can be realized while maintaining the same diameter of the milling head.

[0117] Fig. 7 to Fig. 10 show sections through a flow guiding device 1 according to the embodiments of the Fig. 1 to Fig. 6 in four different blade section planes S. The blade section planes S are arranged in such a way that they are penetrated by the longitudinal axis L of the base body 3 as a plane normal. Starting from the flow inlet 7, the four sections of the Fig. 7 to 10 are arranged with increasing distance along the longitudinal axis L of the base body 3. The blade cutting plane S according to Fig. 10 is furthest away from the flow inlet 7 along the longitudinal axis L.

[0118] The blade section plane S at a point on the longitudinal axis L according to Fig. 7 intersects the first section 12a and the second section 12b of the main body surface 12. At the smallest cross section 9, in particular at the section transition 14 there, the main body surface has a discontinuity. The blade section plane S at a further point of the longitudinal axis L according to Fig. 8 intersects the main body surface in the second section 12b. The blade cutting plane S at a third point of the longitudinal axis L according to Fig. 9 intersects the base body surface 12 in the second section 12b. The blade cutting plane S at a fourth point according to Fig. 10 of the longitudinal axis L intersects the base body surface 12 in the second section 12b and in the third section 12c.

[0119] According to Fig. 7 to Fig. 10 is a surface height H 3 of the blade 4 on the - here pressure-side - surface 11 different to a surface height H 4on the opposite surface 10 of the adjacent blade with respect to the flow channel 6 - here the suction side. The surface height H of the blades 4, in particular the profile of the main body surface 12, is designed such that the surface height H 3 always smaller than the surface height H 4 With this boundary condition, an advantageous cross-sectional profile for the flow channel 6 can be created if, as here, the diameter D3 at the flow outlet 2 is smaller than the diameter D2 at the flow inlet 7 and the main body surface 12 downstream of the smallest cross section 9 is designed as a concavely curved surface which bridges the diameter difference, in particular with the second section 12b.

[0120] According to Fig. 10, the blade cutting plane S intersects the base body surface 12 in the second section 12b and in the third section 12c at a fourth point on the longitudinal axis L. In the section transition 13 between the second section 12b and the third section 12c, the pitch of the second section 12b and the third section 12c is identical. The second section 12b merges tangentially into the third section 12c. The third section 12c is curved with a diameter D3, so that the base body surface 12 is circular at the flow outlet 2.

[0121] Fig. 11a and Fig. 11b show two developed cross sections for blades 4 for flow guiding devices 1 according to Fig. 1 to Fig. 6. In the embodiment of the Fig. 10a, downstream of the smallest cross-section 9, the mutually facing surfaces 10, 11 of the blades 4, in particular the second surface sections 10b, 11b, are completely flat and diverging from one another. The first surface section 10a of surface 10—here, the suction-side surface 10—is convex up to the smallest cross-section 9, and the first surface section 11a of surface 11—here, the pressure-side surface 11—is concave.

[0122] In the embodiment of the Fig. 11b, the surfaces 10, 11 up to the smallest cross section 9, i.e. the first surface sections 10a, 11a, are identical to the embodiment of Fig.11a. Downstream of the smallest cross-section 9, the second surface section 10b of the surface 10—here the suction-side surface 10—is completely flat, and the second surface section 11b of the surface 11—here the pressure-side surface 11—is concave up to the flow outlet 2.

[0123] By varying the distance between the blades 4 orthogonal to the flow direction, the cross-sectional shape of the flow channel 6 can be advantageously constructed based on the design. List of reference symbols 1 flow guide device 2 Flow outlet 3 basic bodies 4 shovels 4a Leading edge of 4 4b trailing edge of 4 5 Basic body circumference 6 flow channel 7 Flow inlet 8 of 3 away end of 4 9 smallest cross-section 10 surface of 4 10a first surface section of 10 before the smallest cross section 9 10b second surface section of 10 after the smallest cross section 9 11 Surface of 4 11a first surface section of 11 before the smallest cross section 9 11b second surface section of 11 after the smallest cross section 9 12 Body surface 12a first section of 12 12b second section of 12 12c third section of 12 13 Section transition from 12 14 section transition from 12 D1 Diameter at end 8 of 4 D2 Diameter at the flow inlet 7 of 3 D3 Diameter at the flow outlet 2 of 3 L Longitudinal axis H 1 Surface height of 4 at the flow inlet 7 H 2 Surface height of 4 at flow outlet 2 H 3 Surface elevation from 4 to 11 in S H4 Surface elevation from 4 to 10 in S H 5 Surface elevation from 4 to 10.11 in E S Blade cutting plane E Flow channel section plane

Claims

[1] Flow guiding device (1) with at least one base body (3), wherein the base body (3) extends along a longitudinal axis (L), wherein the base body (3) has at least one flow channel (6) on a base body circumference (5), wherein the flow channel (6) is delimited in its extension by a base body lateral surface (12) and by two mutually facing surfaces (10, 11), wherein the surfaces (10, 11) are inclined relative to the longitudinal axis (L) of the base body (3), wherein the base body lateral surface (12) is designed such that the two mutually facing surfaces (10, 11) have a different surface height (H) in at least one blade sectional plane (S), and wherein the longitudinal axis (L) is a plane normal to the blade sectional plane (S), characterized bythat the main body surface (12) has at least two sections (12a, 12b, 12c) with different surface shapes in its course, and that the main body surface (12) of an upstream section (12b) is aligned substantially tangentially to the main body surface (12) of a downstream section (12c) at least in a section transition (13) arranged between the two sections (12b, 12c). [2] Flow guiding device (1) according to claim 1, characterized by that the main body surface (12) is further designed such that the surface heights (H) of the mutually facing surfaces (10, 11) are substantially equal in at least one flow channel section plane (E), wherein the flow channel section plane (E) is in each case traversed by a central flow thread in the normal direction. [3] Flow guiding device (1) according to claim 2, characterized bythat an intersection line of the flow channel cutting plane (E) and the blade cutting plane (S) intersects a central flow thread of the flow channel (6). [4] Flow guiding device (1) according to one of claims 1 to 3, characterized by that at least one blade (4) is arranged on the base body circumference (5). [5] Flow guiding device (1) according to one of claims 1 to 3, characterized by that at least two blades (4) are arranged on the base body circumference (5), and that the flow channel (6) is formed between the blades (4). [6] Flow guiding device (1) according to claim 5, characterized by that the mutually facing surfaces (10,11) laterally delimiting the flow channel (6) are the corresponding surfaces (10,11) of the blades (4). [7] Flow guiding device (1) according to one of claims 1 to 3 or 5 or 6, characterized bythat a plurality of blades (4) are arranged on the base body circumference (5), and that at least one flow channel (6) is formed between each two blades (4), so that a plurality of flow channels (6) are formed on the base body circumference (5). [8] Flow guiding device (1) according to one of the preceding claims, characterized by that the flow channel (6) has a smallest cross-section (9) along its course, or that the flow channel (6) has a smallest cross-section (9) along its course, and that the cross-sectional profile of the flow channel (6) has the profile of a Laval nozzle. [9] Flow guiding device (1) according to one of the preceding claims, characterized by that the base body surface (12) is at least partially flat and / or concave and / or convex. [10] Flow guiding device (1) according to claim 8, characterized bythat the base body surface (12) downstream and / or upstream of the smallest cross-section (9) is at least partially flat and / or concave and / or convex. [11] Flow guiding device (1) according to one of claims 5 to 7 and one of claims 8 or 10, characterized by that a surface height (H) of the blades (4) at the flow inlet (7) and / or at the smallest cross-section (9) is smaller than the surface height (H) of the blades (4) at the flow outlet (2) or vice versa. [12] Flow guiding device (1) according to claim 5 and one of claims 8 to 11, characterized by that a surface height (H) of the blades (4), starting from the smallest cross-section (9), increases in the direction of the flow outlet (2) and / or the flow inlet (7). [13] Flow guiding device (1) according to claim 8, characterized bythat at least one surface (10, 11) of the mutually facing surfaces (10, 11) in front of and / or behind the smallest cross section (9) of the flow channels (6) is flat and / or convex and / or concave, or that both mutually facing surfaces (10, 11) in the flow direction in front of and / or behind a smallest cross section (9) of the flow channels (6) are flat and / or concave and / or convex. [14] Flow guiding device (1) according to one of the preceding claims, characterized by that a diameter (D2) of the base body (3) upstream of the flow channel (6) is larger than the diameter (D3) of the base body (3) downstream of the flow channel (6) or vice versa. [15] Flow guiding device (1) according to one of the preceding claims, characterized bythat the base body (3) and the flow channel (6) are formed in one piece, namely that the base body (3) and the flow channel (6) are formed by milling from solid material, or that the base body (3) and the flow channel (6) are formed by an additive manufacturing process. [16] Flow guiding device (1) according to claim 5 or claim 5 and one of claims 6 to 15, characterized by that the base body (3) and the blades (4) are formed in one piece, namely that the base body (3) and the blades (4) are formed by milling from solid material, or that the base body (3) and the blades (4) are formed by an additive manufacturing process. [17] Turbomachine with at least one flow guiding device (1) according to one of claims 1 to 16 as at least one impeller or as at least one guide wheel.

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