Gas Turbine Compressor Stator Seal Leakage Reduction

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Solution Overview

Problem

Air leaks between the rotor and stator vane in gas turbine compressor sections lead to efficiency losses, particularly in engines with gear reduction drives where a larger fan diameter increases the need for improved air redirection and compression efficiency.

Innovation Solution

A compressor section design featuring a drum with frustoconical portions and a smooth inner ring surface with a bump to minimize the gap between rotor blades and the inner ring, reducing leakage and improving sealing efficiency compared to traditional knife-edge seals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional knife-edge seals with abradable material are used, then sealing capability is improved, but device complexity increases and the seal extends further inwardly than desired

Engineering Contradiction:
Improvesealing capabilityVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the complex multi-part knife-edge seal structure with abradable material, retaining only the essential sealing function through a simplified single-piece drum design with optimized geometry

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges multiple seal components into a single integrated drum structure, combining the sealing surface, structural support, and positioning features into one element that reduces part count while maintaining sealing effectiveness

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If a larger fan diameter is used with gear reduction drive, then air delivery capacity to bypass duct is improved, but air leakage between rotor and stator vane increases

Engineering Contradiction:
Improveair delivery capacityVSAvoidair leakage
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent applies local quality optimization by creating a concentrated, localized sealing zone at the drum inner ring surface with specific geometric features (frustoconical portions and bump) that enhance sealing effectiveness precisely where air leakage occurs, without affecting overall fan performance

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If the sealing gap between rotor blades and inner ring is increased, then manufacturing ease is improved, but sealing efficiency deteriorates

Engineering Contradiction:
Improvesealing gap toleranceVSAvoidsealing efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent employs curvature principles by incorporating frustoconical portions and a bump feature on the drum inner ring surface, creating a curved sealing geometry that maintains effective sealing contact while accommodating manufacturing tolerances and thermal expansion

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP2847450B1Gas turbine engine compressor stator seal
Publication Date: 2018.12.05 UNITED TECH CORP
  • EP2847450B1 patent drawingFigure 1
  • EP2847450B1 patent drawingFigure 2
  • EP2847450B1 patent drawingFigure 3~4

AI summary

A compressor section for use in a gas turbine engine has a plurality of compressor stages. Each compressor stage is provided with a rotor hub, and each rotor hub mounts a plurality of compressor blades. A rotor drum extends between adjacent rotor hubs. A plurality of stator stages have an outer ring and a radially inner ring. A plurality of vanes extend between the outer and inner rings. An inner surface of the inner ring is spaced by a gap from an outer surface of the rotor drum. The rotor drum is provided with a plurality of blades having a general airfoil shape to resist leakage across the gap.