Heat Exchanger Leakage Mitigation in Gas Turbine Engine Cases

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Solution Overview

Problem

Gas turbine engine case assemblies experience airflow leakage due to heated and pressurized air escaping through minor gaps, leading to unfavorable engine performance and air impingements on external components, which existing heat exchangers fail to adequately address.

Innovation Solution

A heat exchanger is strategically placed at the joint between engine case portions to inhibit airflow through the gap while performing heat transfer functions, utilizing thermal expansion to minimize leakage and optimize airflow control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional heat exchangers are used in engine case assemblies, then heat transfer function is provided, but airflow leakage through gaps between case parts cannot be controlled

Engineering Contradiction:
Improveairflow leakage controlVSAvoidheat exchanger structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The heat exchanger is designed to perform dual functions: heat transfer between working fluids and airflow leakage control through thermal expansion. By making the heat exchanger structure responsive to temperature changes, it simultaneously achieves thermal management and sealing purposes, eliminating the need for separate leakage control mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The heat exchanger utilizes thermal expansion of its structure in response to temperature changes to control airflow leakage. As the heat exchanger temperature increases during engine operation, the material expands and closes gaps between case parts, thereby reducing leakage while maintaining the heat transfer function.

Inventive Principle:
Principle #37Thermal expansion

2Use of energy by moving object

If heat exchanger structure is designed to respond to thermal stresses, then thermal energy transfer is achieved, but structural integrity under thermal loading is compromised

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidstructural integrity
Core Design Contradiction:
Use of energy by moving objectVSStrength

Solution Approach 1:

The heat exchanger is designed to utilize controlled thermal expansion to achieve both heat transfer and leakage control. The structural design allows for predictable dimensional changes under thermal loading while maintaining overall integrity, transforming the thermal stress challenge into a beneficial sealing mechanism.

Inventive Principle:
Principle #37Thermal expansion

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 heat exchanger effectively reduces airflow leakage and enhances engine performance by utilizing thermal expansion to close the leakage pathway, while also facilitating heat transfer, thus improving the structural integrity and operational efficiency of the gas turbine engine.

Implementation Method 1

the heat exchanger configured to inhibit air flow through the gap... utilizing thermal expansion to minimize leakage

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

Heat is transferred to and from various fluids via heat exchangers (HEX)... configured with a heat transfer function

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP4407169A1Engine case leakage mitigation heat exchanger
Publication Date: 2024.07.31 RTX CORP
  • EP4407169A1 patent drawingFigure 1
  • EP4407169A1 patent drawingFigure 2~4
  • EP4407169A1 patent drawing

AI summary

A heat exchanger for controlling case leakage including a joint formed between a first case portion proximate a second case portion; a gap formed within the joint; and the heat exchanger operatively coupled to the case proximate the joint, the heat exchanger configured to inhibit air flow through the gap.