Gas Turbine Diffuser Airfoils for Debris Collection

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Solution Overview

Problem

Gas turbine engines operating in harsh environments face contamination from debris like sand and dirt, which can adhere to surfaces and disrupt cooling holes and passages, particularly in the combustor section, leading to potential blockages.

Innovation Solution

A diffuser system with airfoils located in a high-velocity region of the annular fluid passage, supported by struts and featuring a leading edge with resistive heat strips or bleed air passages, designed to collect debris by increasing adhesion through high velocity and temperature, with a cross-sectional area greater than 50% of the passage to enhance debris impact and collection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If debris collection surfaces are added in the diffuser, then debris collection efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvedebris collection efficiencyVSAvoiddiffuser structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The diffuser is segmented into multiple functional zones: a high-velocity region with collection surfaces for debris capture, and a diffusion region for flow deceleration. The collection surfaces are further segmented into leading edges and side surfaces, allowing targeted debris collection without requiring complete structural redesign of the entire diffuser.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The debris collection function is extracted as a separate feature from the main diffuser body through additively manufactured collection surfaces. These surfaces can be removed and replaced independently, allowing the main diffuser structure to remain intact while enabling effective debris collection.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If airfoils are placed in high velocity region with large cross-sectional area, then debris adhesion is improved, but pressure loss increases

Engineering Contradiction:
Improvedebris adhesionVSAvoidpressure loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The collection surfaces are strategically placed only in the high-velocity region where debris adhesion is most effective, rather than throughout the entire diffuser. The surfaces have specific geometric features (leading edges, side surfaces) optimized for local debris capture, while the rest of the diffuser maintains smooth flow paths to minimize pressure loss.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Rather than attempting to collect all debris throughout the entire diffuser passage, the invention uses partial action by concentrating collection surfaces in the high-velocity region where they are most effective. This focused approach achieves sufficient debris collection without the excessive pressure loss that would result from遍布 collection surfaces.

Inventive Principle:
Principle #16Partial or excessive action

3Ease of repair

If collection surfaces are made removable, then maintenance ease is improved, but structural complexity increases

Engineering Contradiction:
Improvemaintenance easeVSAvoidattachment structure complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The collection surfaces are segmented as separate removable components from the main diffuser body. This segmentation allows the collection surfaces to be independently removed for cleaning or replacement without disassembling the entire diffuser, simplifying maintenance while using simple attachment mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The collection surfaces are designed to be easily removed and replaced as consumable components. After accumulating debris, the surfaces can be removed, cleaned or replaced, and reinstalled without affecting the permanent diffuser structure, enabling efficient maintenance cycles.

Inventive Principle:
Principle #34Discarding and recovering

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

Effectively reduces the amount of debris reaching the combustor by collecting sand and dirt in the diffuser, preventing blockages and ensuring smooth airflow, with the airfoils being removable for maintenance.

Implementation Method 1

collect debris by increasing adhesion through high velocity and temperature

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

heating the plurality of airfoils to promote debris to collect on the leading edge

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

heating the plurality of airfoils to promote debris to collect on the leading edge

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 4

a cross-sectional area of the plurality of airfoils is greater than 50% of the cross-sectional area of the annular fluid passage

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP3536931B1Dirt collection for gas turbine engine
Publication Date: 2023.08.02 RTX CORP
  • EP3536931B1 patent drawingFigure 1
  • EP3536931B1 patent drawingFigure 2~4

AI summary

A diffuser (60) for a gas turbine engine includes an annular fluid passage (62) that fluidly connects a diffuser inlet (66) to a diffuser outlet (67). A plurality of airfoils (74) are located in the annular fluid passage (62) and each has a collection surface.