Rotor Blade Rib Coating for Gas Turbine Sealing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current gas turbine rotor blades with radially outward ribs lack an effective sealing mechanism to minimize leakage gaps, which affects efficiency.

Innovation Solution

A rotor blade with a radially outer rib arrangement featuring multiple ribs coated on their side faces, where the coating thickness increases radially outward, forming an expanding outer contour that reduces the axial gap between adjacent ribs, enhancing the sealing surface area and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ribs are provided on the shroud to reduce leakage gap, then sealing effect is improved, but axial gap between adjacent ribs increases reducing sealing effectiveness

Engineering Contradiction:
Improvesealing effectVSAvoidaxial gap between ribs
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent transitions from uniform thickness ribs to conically shaped ribs where thickness varies in the radial dimension. The rib thickness increases from root to tip in the radial direction, creating a wedge-shaped profile that reduces axial gaps between adjacent ribs while maintaining structural integrity. This dimensional variation in thickness resolves the contradiction by addressing the sealing gap issue through radial dimension modification rather than simply increasing rib height.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the thickness parameter of the ribs along their length, specifically increasing thickness from the root toward the tip in a conical configuration. This parameter variation allows the rib to simultaneously provide structural support at the root and effective sealing at the tip where the axial gaps are smallest. The continuous variation of the thickness parameter resolves the contradiction between maintaining rib strength and reducing axial gaps.

Inventive Principle:
Principle #35Parameter changes

2Area of stationary object

If coating thickness increases radially outward on rib surfaces, then sealing surface area is increased, but coating complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvesealing surface areaVSAvoidcoating application complexity
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The patent applies coating primarily at the radial tip region of the ribs rather than uniformly across the entire rib surface. By concentrating the coating application in the radial direction at the sealing-critical tip area, the patent increases the effective sealing surface area where it is most needed while avoiding the complexity of coating the entire rib structure. This selective regional coating resolves the contradiction between maximizing sealing area and simplifying manufacturing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If multiple ribs are arranged axially to reduce leakage, then sealing effectiveness is improved, but device complexity increases

Engineering Contradiction:
Improvesealing effectivenessVSAvoidrib arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies different properties to different regions of the rib structure. The root region maintains uniform thickness for structural support, while the tip region features increased thickness with conical shaping for enhanced sealing. This local differentiation allows the rib arrangement to achieve effective sealing with fewer, simpler ribs rather than requiring multiple complex ribs throughout the entire structure, thus resolving the contradiction between sealing effectiveness and device complexity.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution significantly reduces leakage between ribs, improving the sealing effect and overall efficiency of the gas turbine by creating a larger sealing surface area with a minimized axial gap, while maintaining a robust coating that prevents flaking.

Implementation Method 1

the ribs have a coating on at least the two side faces in each case. These coatings are connected to one another via their radially outer end faces of the respective ribs... which grinds into a sacrificial material of the sealing surface

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP2604797B1Rotor blade with a rib assembly with an abrasive coating
Publication Date: 2020.01.22 MTU AERO ENGINES GMBH
  • EP2604797B1 patent drawingFigure 1~4

AI summary

The rotating blade (5) has a radially outer rib arrangement with ribs (2) onto which a coating is arranged. The ribs are arranged behind one another in the axial direction, and the coating is arranged on each of two adjacent ribs. The rib arrangement is arranged on an oblique shroud (1) in the axial direction of the rotating blade. The coating is provided with an outer contour which is extended axially outwardly in the radial direction, in a meridian section. An independent claim is included for a method for coating rib of radially outer rib arrangement of rotating blade.