# US 2013/0156562 A1 · Turbomachine and turbomachine stage

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- Number: US 2013/0156562 A1
- Document ID: US20130156562A1
- Status: Published application
- Kind: A1
- Application number: 13/687,789
- Filed: 2012-11-28
- Published: 2013-06-20
- Earliest claimed: 2011-12-20
- Assignees: MTU Aero Engines AG
- Inventors: Inga MAHLE; Jochen GIER; Kai KOERBER; Michael ENGELKE
- Web page: https://patentgrep.com/patent/US20130156562A1

## CPC

- F01D 9/00: Stators
- F01D 5/143: {Contour of the outer or inner working fluid flow path wall, i.e. shroud or hub contour}
- F05D 2250/184: sinusoidal
- F05D 2250/611: undulated
- Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A turbomachine stage including guide vanes, radially inner and/or radially outer airfoil platforms, which together form a guide vane cascade, and further including rotor blades, radially inner and/or radially outer airfoil platforms, which together form a rotor blade cascade adjacent to the guide vane cascade. Radially outer airfoil platforms have cascade regions extending between circumferentially adjacent airfoils, and gap regions which radially and/or axially bound an axial gap extending axially between the guide vane cascade and the rotor blade cascade. A contour of at least one of these gap regions varies, in particular periodically, in the radial and/or axial direction around the circumference.

## Claims

### Claim 1

A turbomachine stage comprising:
guide vanes;
a radially outer guide vane airfoil platform defining with the guide vanes a guide vane cascade, the radially outer guide vane airfoil platform having a guide vane cascade region and a guide vane gap region extending axially beyond the guide vane cascade region;
rotor blades;
a radially outer rotor vane airfoil platform defining with the rotor blades a rotor blade cascade, the radially outer rotor vane airfoil platform having a rotor vane cascade region and a rotor vane gap region extending axially beyond the rotor vane cascade region;
the rotor blade cascade being adjacent to the guide vane cascade, the guide vane gap region and the rotor vane gap region at least one of radially and axially defining an axial gap extending axially between the guide vane cascade and the rotor blade cascade;
a contour of at least one of the guide vane gap region and the rotor vane gap region varying in at least one of the radial and the axial direction around a circumference, and an at least one of axially and radially opposite contour of the other of the guide vane gap region and the rotor vane gap region varying around the circumference.

### Claim 2 (depends on 1)

The turbomachine stage as recited in claim 1 wherein the contour and the opposite contour are radially opposite.

### Claim 3 (depends on 2)

The turbomachine stage as recited in claim 2 wherein the contour and the opposite contour vary identically.

### Claim 4 (depends on 1)

The turbomachine stage as recited in claim 1 wherein the contour varies both radially and axially.

### Claim 5 (depends on 1)

The turbomachine as recited in claim 1 wherein the contour varially radially but is constant in the axial direction.

### Claim 6 (depends on 1)

The turbomachine stage as recited in claim 1 wherein at least one of the guide vane or rotor vane gap region merges smoothly into the respective guide vane or rotor vane cascade region.

### Claim 7 (depends on 1)

The turbomachine stage as recited in claim 1 wherein the contour varies radially and an extreme extent of the radially varying contour is circumferentially located in a pressure-side half of a segment between two respective adjacent airfoil leading edges or in a suction-side half of a segment between two respective adjacent airfoil trailing edges.

### Claim 8 (depends on 1)

The turbomachine stage as recited in claim 1 wherein the contour varies radially and a maximum variation in the radial direction of the respectve guide vane or rotor vane gap region is no more than 50% of the pitch of the respective guide vane or rotor vane cascade.

### Claim 9 (depends on 8)

The turbomachine as recited in claim 8 wherein the maximum variation is no more than 40%.

### Claim 10 (depends on 1)

The turbomachine stage as recited in claim 1 wherein the contour varies axially and wherein an extreme extent of the axially varying contour is circumferentially located in the region of a respective airfoil edge.

### Claim 11 (depends on 10)

The turbomachine as recited in claim 10 wherein the extreme extent is circumferentially spaced from the respective airfoil edge by no more than 25% of the cascade pitch.

### Claim 12 (depends on 1)

The turbomachine stage as recited in claim 1 wherein the contour varies axially and a maximum variation in the axial direction is no more than 50% the pitch of the respective guide vane or rotor vane cascade.

### Claim 13 (depends on 1)

The turbomachine stage as recited in claim 1 wherein the contour varies periodically.

### Claim 14 (depends on 13)

The turbomachine stage as recited in claim 13 wherein the opposite contour varies identically with the contour.

### Claim 15 (depends on 13)

The turbomachine stage as recited in claim 13 wherein the opposite contour varies identically with the contour.

### Claim 16 (depends on 1)

A turbomachine comprising at least one turbomachine stage as recited in claim 1.

### Claim 17 (depends on 1)

A gas turbine comprising at least one turbomachine stage as recited in claim 1.

### Claim 18 (depends on 1)

An aircraft engine gas turbine comprising at least one turbomachine stage as recited in claim 1.

### Claim 19 (depends on 1)

A compressor stage comprising the turbomachine stage as recited in claim 1.

### Claim 20 (depends on 1)

A turbine stage comprising the turbomachine stage as recited in claim 1.