Engine Conduit Blockage Testing Using a Freezing Plug Header

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Solution Overview

Problem

Non-destructive inspection of internal conduits in gas turbine engines fabricated via additive manufacturing is challenging due to the difficulty in detecting blockages in fuel rails and other fluid components, which affects the reliability and cost-effectiveness of miniature gas turbine engines.

Innovation Solution

A method involving a fluid-blocking header that attaches to the engine casing or fluid manifold, freezes plugging media within the conduit using a coolant, and analyzes flow characteristics at fuel injectors or outlets to assess blockages, utilizing a cooling system like a fluid cooler or thermoelectric cooler to facilitate heat transfer and detect blockages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If additive manufacturing is used to fabricate engine components with internal conduits, then cost and weight savings are realized, but non-destructive inspection of conduit integrity becomes challenging

Engineering Contradiction:
Improvemanufacturing cost and weightVSAvoidconduit blockage detection
Core Design Contradiction:
Ease of manufactureVSDifficulty of detecting and measuring

Solution Approach 1:

A plugging fluid is introduced as an intermediary substance to fill the internal fuel conduit. This fluid serves as a mediator that allows detection of blockages by attempting to move through the conduit system. When a blockage exists, the plugging fluid cannot pass through, providing a detectable indication of the problem without requiring complex inspection equipment.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The plugging fluid undergoes a phase transition from liquid to solid when frozen by the fluid-blocking header. This phase change allows the fluid to be introduced in a manageable liquid state, then frozen to block the conduit for sealing purposes, and potentially melted again for removal. The phase transition enables easy introduction and removal of the detection medium.

Inventive Principle:
Principle #36Phase transitions

2Measurement precision

If conventional leak detection methods are used on additive manufactured components, then inspection can be performed, but the methods are ineffective for detecting blockages in internal conduits

Engineering Contradiction:
Improveblockage detection accuracyVSAvoidinternal conduit inspection
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

Pressurized fluid is used to test the internal conduit system. By introducing plugging fluid under pressure and attempting to move it through the conduit network, the method leverages hydraulic principles to detect blockages. The pressurized fluid approach is more effective than conventional visual or surface inspection methods for detecting internal obstructions.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The physical state of the plugging fluid is changed by freezing it with the fluid-blocking header. This parameter change (temperature and phase) allows the fluid to be introduced, then frozen to seal sections of the conduit for isolated testing. The ability to change the fluid's physical parameters enables precise control over the detection process.

Inventive Principle:
Principle #35Parameter changes

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 method effectively identifies blockages in internal conduits, ensuring the integrity and functionality of fuel rails and other fluid components, enhancing the reliability and cost-effectiveness of miniature gas turbine engines by non-destructively inspecting additive manufacturing components.

Implementation Method 1

a cooling system coupled to the fluid-blocking header and configured to provide a heat sink to the component when activated

Methodology Applied
Scientific EffectFreezing: Freezing

Implementation Method 2

utilizing a cooling system like a fluid cooler or thermoelectric cooler to facilitate heat transfer and detect blockages

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3760840B1Apparatus and method for testing additively manufactured engine components
Publication Date: 2022.05.04 RTX CORP
  • EP3760840B1 patent drawingFigure 1
  • EP3760840B1 patent drawingFigure 2A
  • EP3760840B1 patent drawingFigure 2B

AI summary

A method for inspecting a component made using an additive manufacturing process, the component having an internal conduit, is disclosed. In various embodiments, the method includes the steps of: attaching a fluid-blocking header (372-1, 372-2; 482; 582; 682) to the component, the fluid-blocking header having an internal conformal surface (374; 474; 574; 674) configured to mate with an external conformal surface (376; 476; 576; 676) of the component; introducing a plugging media into the internal conduit; activating the fluid-blocking header to freeze the plugging media in a vicinity of the fluid-blocking header; pressurizing the internal conduit of the component; and analyzing a fluid flow characteristic at an outlet of the component to assess an occurrence of a blockage within the internal conduit.