Diffuser Case Strut Direct Air Feed Cooling

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Solution Overview

Problem

The increased T3 temperature in turbine engines due to higher bypass ratios leads to elevated temperatures beyond typical capabilities, reducing the lifespan of compressor components, and existing cooled air systems suffer from air losses and complex mixing issues.

Innovation Solution

A diffuser case strut with a direct air feed passage that intersects with a cavity, receiving cooled air from a heat exchanger and delivering it directly to the compressor hub, spacer arm, and aftmost compressor stage via a compressor on-board injection system, minimizing air losses and optimizing cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a higher bypass ratio is used to increase fan air delivery, then the volume of air delivered into the bypass duct increases, but the temperature at the exit of the high pressure compressor (T3) increases beyond typical capabilities, reducing compressor component lifespan

Engineering Contradiction:
Improvevolume of air delivered into bypass ductVSAvoidtemperature at exit of high pressure compressor (T3)
Core Design Contradiction:
Quantity of substanceVSTemperature

Solution Approach 1:

The patent segments the air delivery system into two distinct pathways: a bypass duct for unconditioned air and a direct feed air passage for cooled air. This segmentation allows the system to deliver large volumes of air while selectively cooling critical components, resolving the contradiction between high bypass ratio operation and compressor temperature management

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a heat exchanger as an intermediary device between the compressed air source and the compressor components. The heat exchanger conditions the air by removing excess heat before delivery, enabling high bypass ratio operation without subjecting compressor components to excessive temperatures

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a cooled air system with heat exchanger and COBI system is used to cool compressor components, then the lifespan of compressor components increases, but air losses occur due to circuitous flow routes and complex mixing

Engineering Contradiction:
Improvelifespan of compressor componentsVSAvoidair losses due to circuitous flow routes
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent extracts the cooling function from the complex mixed system and creates a separate direct feed air passage that delivers cooled air directly to compressor components. This eliminates the circuitous flow routes and mixing losses associated with integrated cooled air systems, maintaining component reliability while reducing air losses

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies preliminary cooling action by conditioning the air in the heat exchanger before it enters the direct feed air passage. This pre-conditioning ensures that the air reaches compressor components at the appropriate temperature without requiring complex in-situ cooling mechanisms, thereby reducing overall system complexity and air losses

Inventive Principle:
Principle #10Preliminary action

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 solution provides efficient cooling to the compressor components, reducing temperature-related stress and extending their lifespan by delivering conditioned air directly to critical areas, thereby improving the utilization of air and reducing thermal issues.

Implementation Method 1

receives cooled air from a heat exchanger

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

direct air feed passage that intersects with a cavity, receiving cooled air from a heat exchanger and delivering it directly

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP2994627B1Diffuser case strut for a turbine engine
Publication Date: 2021.06.30 RTX CORP
  • EP2994627B1 patent drawingFigure 1
  • EP2994627B1 patent drawingFigure 2
  • EP2994627B1 patent drawingFigure 3~4

AI summary

An inner diffuser case for a turbine engine includes a fore gas path edge and an aft gas path edge defining a strut, wherein each of the fore gas path edge and the aft gas path edge include a gas path opening, a support cone structure extending radially outward from the strut, wherein the support cone structure is operable to structurally connect the strut to a turbine engine case, a diffuser case skirt structure extending radially inward from the strut, wherein the diffuser case skirt structure is operable to structurally connect the diffuser case strut to an inner support structure of the turbine engine, and at least one direct feed air passage passing radially through the strut including a radially outward upper mixing chamber opening and a radially inward direct air feed opening, the direct air feed opening is connected to a direct air feed.