Gas Turbine Mid-Vane Platform Gap Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Leakage between components in gas turbine engines, particularly between the combustor and turbine sections, leads to efficiency losses due to thermal expansion differences between dissimilar materials, resulting in larger design gaps and increased leakage.

Innovation Solution

The use of ceramic matrix composite or monolithic composite materials for the combustor panel and blade outer air seal, with a full, unsegmented, closed ring configuration and scallops to accommodate the vane leading and trailing edges, reduces the platform gap and eliminates circumferential gaps, thereby minimizing leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If dissimilar materials are used for combustor and turbine components, then material performance and temperature resistance are improved, but thermal expansion differences cause larger design gaps and increased leakage

Engineering Contradiction:

Improvetemperature resistanceVSAvoidleakage loss

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The patent changes the material parameter from traditional metal alloys to ceramic matrix composites (CMC) and monolithic composite materials. These materials have thermal expansion coefficients that better match between dissimilar components, allowing for reduced platform gaps while maintaining temperature resistance. The design gap is reduced from typical values to as little as 0.002-0.006 inches without causing binding during thermal cycling.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs ceramic matrix composite (CMC) materials for combustor panels and monolithic composite materials for blade outer air seals. These composite materials provide both high-temperature resistance and controlled thermal expansion properties, enabling reduced gaps between dissimilar components while maintaining structural integrity and thermal performance.

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If larger design gaps are used between dissimilar material components, then thermal expansion compatibility is improved, but leakage between components increases

Engineering Contradiction:

Improvethermal expansion compatibilityVSAvoidleakage loss

Core Design Contradiction:

Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The patent changes the thermal expansion parameter by selecting materials with matched expansion characteristics. CMC combustor panels and monolithic composite air seals have thermal expansion coefficients that are compatible with each other, allowing for minimal platform gaps (0.002-0.006 inches) that prevent both binding during thermal cycling and excessive leakage.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If traditional segmented combustor panels are used, then manufacturing and assembly are simplified, but circumferential gaps increase leakage

Engineering Contradiction:

Improveassembly simplicityVSAvoidcircumferential leakage

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent reverses the segmentation approach by using a single-piece, unsegmented, closed-ring configuration for both the combustor panel and blade outer air seal. This eliminates circumferential gaps at the joints that would otherwise create leakage paths, while the CMC and monolithic composite materials enable this complex geometry to be manufactured as integral pieces.

Inventive Principle:

Principle #1Segmentation

4Ease of manufacture

If multiple separate components are used for combustor panel and air seal, then manufacturing flexibility is improved, but assembly complexity and leakage paths increase

Engineering Contradiction:

Improvemanufacturing flexibilityVSAvoidassembly complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges the combustor panel and blade outer air seal into a single integrated closed-ring component. This eliminates the interface between separate parts, removing the leakage path that would exist at the joint. The monolithic construction simplifies assembly while CMC manufacturing techniques provide the flexibility needed to create this complex integrated geometry.

Inventive Principle:

Principle #5Merging (Combining)

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

This configuration reduces leakage, improves turbine performance, and maintains a consistent thermal response, leading to enhanced cycle and turbine efficiency while reducing assembly complexity and costs.

Implementation Method 1

dissimilar materials may be utilized for the combustor, vane platforms, BOAS, etc., resulting in different thermal expansion properties of the components

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS11181005B2Gas turbine engine assembly with mid-vane outer platform gap

Publication Date: 2021.11.23 RTX CORP

AI summary

An assembly for a gas turbine engine includes a vane assembly having an inner platform and an airfoil section extending from the inner platform. A first combustor panel extends at least partially along the vane from upstream of the vane, and a blade outer air seal extends at least partially along the vane from downstream of the vane. The first combustor panel and the blade outer air seal define a platform gap located between a leading edge of the airfoil section of the vane and a trailing edge of the airfoil section of the vane.