US-12624639-B2 - Turbine module for a turbomachine

US12624639B2US 12624639 B2US12624639 B2US 12624639B2US-12624639-B2

Abstract

The application relates to a turbine module for a turbomachine, the turbine module comprising: a main channel to guide a main flow through the turbine module; a stator vane comprising a stator airfoil and an outer platform; a cavity extending at least partly radially outside of the stator airfoil; the cavity comprising an inlet opening for guiding a part of the main flow into the cavity and an outlet for a reinjection of the part of the main flow from the cavity into the main channel, wherein an inner wall of the outer platform defines the main channel radially, and wherein the inlet opening is arranged on a radial position radially outside of the inner wall of the outer platform.

Inventors

Michal Piatek
Roman Seiband
Hermann Klingels
Kacper PALKUS
Christian Pfalzgraf

Assignees

MTU Aero Engines AG

Dates

Publication Date: 20260512
Application Date: 20250721
Priority Date: 20240726

Claims (19)

1 . A turbine module for a turbomachine, the turbine module comprising: a main channel to guide a main flow through the turbine module; a stator vane comprising a stator airfoil and an outer platform; the outer platform having an inner wall surface and an outer wall surface; a cavity extending at least partly radially outside of the stator airfoil; the cavity comprising an inlet opening for guiding a part of the main flow into the cavity and an outlet for a reinjection of the part of the main flow from the cavity ( 30 ) into the main channel, wherein an inner wall of the outer platform defines the main channel radially, and wherein the inlet opening is arranged on a radial position radially outside of the inner wall surface of the outer platform and radially inside of the outer wall surface of the outer platform.
2 . The turbine module according to claim 1 , wherein the inlet opening is arranged in an axial front face of the outer platform.
3 . The turbine module according to claim 1 , wherein the outer platform comprises a front vane hook, wherein the cavity extends radially inside of the front vane hook and keeps the functionality of the front vane hook.
4 . The turbine module according to claim 1 , wherein the cavity comprises a number n of inlet openings, where n≥2, and a number m of outlet openings, where m≥1, wherein circumferentially adjacent inlet openings are separated by ribs.
5 . The turbine module according to claim 4 , wherein the number n of inlet openings is twice the number m of outlet openings, n=2m.
6 . The turbine module according to claim 1 , wherein the cavity extends as a closed channel between the inlet opening or openings and the outlet opening or openings.
7 . The turbine module according to claim 6 , wherein the closed channel is defined within the outer platform.
8 . The turbine module according to claim 1 , wherein all outlet openings of the cavity are arranged in the inner wall of the outer platform.
9 . The turbine module according to claim 1 , further comprising: a rotor blade downstream of the stator vane; wherein at least one outlet opening of the cavity is arranged in an outer air seal cavity of the rotor blade downstream of the stator vane.
10 . The turbine module according to claim 1 , the stator vane belonging to a stator segment, wherein the cavity is circumferentially defined within the stator segment.
11 . The turbine module according to claim 10 , wherein the cavity is circumferentially defined between two neighboring stator airfoils.
12 . The turbine module according to claim 10 , wherein the stator segment comprises a circumferentially offset further cavity, which has a further inlet opening and a further outlet opening, wherein the cavities are, apart from their respective communication with the main channel, fluidically isolated from each other.
13 . The turbine module according to claim 1 , further comprising: a rotor blade upstream of the stator vane; wherein the part of the main flow guided into the cavity is a leakage flow of the rotor blade.
14 . A turbomachine with a turbine module according to claim 1 .
15 . Using a turbomachine according to claim 14 , wherein a part of the main flow is guided into the cavity and reinjected from the cavity into the main channel.
16 . A turbine module for a turbomachine, the turbine module comprising: a main channel to guide a main flow through the turbine module; a stator vane comprising a stator airfoil and an outer platform; a cavity extending at least partly radially outside of the stator airfoil; the cavity comprising an inlet opening for guiding a part of the main flow into the cavity and an outlet for a reinjection of the part of the main flow from the cavity ( 30 ) into the main channel; wherein the cavity comprises a number n of inlet openings, where n≥2, and a number m of outlet openings, where m≥1, wherein circumferentially adjacent inlet openings are separated by ribs; wherein an inner wall of the outer platform defines the main channel radially, and wherein the inlet opening is arranged on a radial position radially outside of the inner wall surface of the outer platform.
17 . A turbine module for a turbomachine, the turbine module comprising: a main channel to guide a main flow through the turbine module; a stator vane comprising a stator airfoil and an outer platform; a rotor blade downstream of the stator vane; a cavity extending at least partly radially outside of the stator airfoil; the cavity comprising an inlet opening for guiding a part of the main flow into the cavity and an outlet for a reinjection of the part of the main flow from the cavity ( 30 ) into the main channel, wherein an inner wall of the outer platform defines the main channel radially, and wherein the inlet opening is arranged on a radial position radially outside of the inner wall surface of the outer platform, wherein at least one outlet opening of the cavity is arranged in an outer air seal cavity of the rotor blade downstream of the stator vane.
18 . A turbine module for a turbomachine, the turbine module comprising: a main channel to guide a main flow through the turbine module; a stator vane comprising a stator airfoil and an outer platform; a cavity extending at least partly radially outside of the stator airfoil; wherein the cavity is circumferentially defined between two neighboring stator airfoils, the stator vane belonging to a stator segment, wherein the cavity is circumferentially defined within the stator segment; the cavity comprising an inlet opening for guiding a part of the main flow into the cavity and an outlet for a reinjection of the part of the main flow from the cavity ( 30 ) into the main channel; wherein an inner wall of the outer platform defines the main channel radially, and wherein the inlet opening is arranged on a radial position radially outside of the inner wall surface of the outer platform.
19 . A turbine module for a turbomachine, the turbine module comprising: a main channel to guide a main flow through the turbine module; a stator vane comprising a stator airfoil and an outer platform; a cavity extending at least partly radially outside of the stator airfoil; the stator vane belonging to a stator segment, wherein the cavity is circumferentially defined within the stator segment; the stator segment comprises a circumferentially offset further cavity, which has a further inlet opening and a further outlet opening, wherein the cavities are, apart from their respective communication with the main channel, fluidically isolated from each other; the cavity comprising an inlet opening for guiding a part of the main flow into the cavity and an outlet for a reinjection of the part of the main flow from the cavity ( 30 ) into the main channel; wherein an inner wall of the outer platform defines the main channel radially, and wherein the inlet opening is arranged on a radial position radially outside of the inner wall surface of the outer platform.

Description

BACKGROUND OF THE INVENTION The present application relates to a turbine module for a turbomachine. Turbomachines can be used in jet engines, e.g. turbofan engines. Functionally, the turbomachine may be divided into a compressor, a combustion chamber and a turbine. In the case of the jet engine, for example, air that is sucked in is compressed by the compressor and burned with added fuel, e.g. kerosene, in the combustion chamber located downstream. The resulting hot gas, a mixture of combustion gas and air, flows through the turbine located downstream and is expanded in this process. The turbine extracts energy from the hot gas to drive the compressor, for instance. This shall illustrate a typical application, alternatively the turbine module can for instance be used in a stationary gas turbine. SUMMARY OF THE INVENTION Examples of the present application are direct at an advantageous turbine module. In the embodiment of the present invention, the turbine module comprises a main channel, a stator vane with a stator airfoil and a cavity, which extends at least partly radially outside of the stator airfoil. The cavity comprises an inlet opening, through which a part of a main flow in the main channel may be extracted from the main channel into the cavity. Further, it comprises an outlet, through which the part of the main flow extracted from the main channel and guided through the cavity is reinjected to the main channel in operation. In addition to the stator airfoil, the stator vane comprises an outer platform arranged radially outside of the stator airfoil. An inner wall of the outer platform defines the main channel radially, i.e. radially outwards. In the embodiment of claim 1, the inlet opening of the cavity is arranged on a radial position radially outside of the inner wall of the outer platform. Arranging the inlet opening not in the inner wall of the outer platform, but radially outside, can for instance have fluidical or structural-mechanical advantages, e.g. reduce an influence on the main flow or an impact on the structural integrity of the outer platform. Generally, the main flow through the main channel, i.e. hot gas flow, can possess flow regions of higher losses due to the presence of secondary flows, for example due to tip clearance losses of a rotating rotor blade in a rotor passage. Flow disturbances starting in the rotor passage can propagate in a stator passage downstream and disturb the inlet flow of a stator vane. An approach of the present application is to bleed a part of the main flow, e.g. from a flow region of higher losses, away into the cavity and reinject this flow back into the main channel at a downstream location. In simple words, at least a portion of the airfoil of the downstream stator vane is bypassed, e.g. at least its leading edge. As discussed in further detail below, e.g. a leakage flow of a rotor passage arranged upstream of the stator vane may be extracted from the main channel through the inlet opening into the cavity, e.g. a tip leakage flow going over the tip of the rotor blade. Such a tip leakage flow may be reduced by a so-called outer air seal of the rotor passage, e.g. shrouded blades in combination with a labyrinth seal at the casing, nonetheless a certain tip leakage may remain. In comparison to the main flow, the leakage flow can for instance have a different angle, because the main flow is reoriented when passing the rotor passage. Independently of these details, the tip leakage flow, or in more general words, any disturbed or misoriented flow portion, can be extracted to bypass at least the leading edge of the stator airfoil. In general, a reinjection of the bypassed part of the main flow may occur at any downstream position, e.g. at another stator vane following downstream (bypassing also a rotor passage in between). Alternatively, at least some of the bypassed flow or the entire bypassed flow may be reinjected within the stator vane, e.g. behind the trailing edge but still in front of a rear end of the outer platform or at an axial position within the stator airfoil, see in detail below. Independently of these details, the reinjection may be adapted to and/or used for influencing the flow characteristics of the main flow, e.g. to energize a boundary layer and for example prevent a flow separation, or to improve the circumferential mixing of the secondary flows and mitigate a passage vortex, for example, in the stator passage. Further embodiments can be found in the dependent claims and in the entire disclosure, wherein in the description of the features, a distinction is not always made in detail between device and method or use aspects; the disclosure is to be read implicitly with regard to all claim categories. If, for example, an advantage of the module is described in a specific application, this is to be understood at the same time as a disclosure of a corresponding use. For bypassing the stator airfoil, i.e. at least the leading edge thereof, the