Gas Turbine Combustor Shell Mitigating Particulate Accumulation

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Solution Overview

Problem

Particulates in the cooling air of gas turbine engine combustors accumulate on heat shield panels, reducing their cooling efficiency and durability due to turbulent aerodynamics in the impingement cavity, leading to increased dirt deposition and potential blockages.

Innovation Solution

The combustor design includes primary apertures in the combustion liner configured to direct airflow and particulates at non-perpendicular impingement angles, minimizing local low velocity regions and reducing particulate collection by adjusting the impingement angle and flow direction within the impingement cavity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling air is channeled through the impingement cavity to cool the heat shield panels, then the cooling efficiency is improved, but turbulent aerodynamics cause particulates to accumulate on the panels, reducing durability and cooling performance over time

Engineering Contradiction:
Improveheat shield panel temperatureVSAvoidcooling system durability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent modifies the aerodynamic parameters of the cooling airflow by adjusting the cavity geometry (length, width, depth ratios) and inlet conditions to transform the turbulent flow regime into a more laminar flow pattern. This reduces the chaotic eddies and recirculation zones that cause particulate accumulation, while maintaining effective convective heat transfer from the heat shield panels.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs curved or rounded cavity geometries rather than sharp angular transitions. The curved surfaces guide the cooling airflow more smoothly through the impingement cavity, reducing flow separation and turbulence intensity. This streamlined geometry minimizes low-velocity recirculation zones where particulates would otherwise settle, while still providing effective cooling coverage.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Strength

If the impingement cavity is designed for effective cooling, then heat shield protection is improved, but turbulent flow creates local low velocity regions that increase particulate deposition

Engineering Contradiction:
Improveheat shield protectionVSAvoidparticulate deposition
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent replaces reliance on purely mechanical/turbulent flow mixing with a more controlled flow management approach. By carefully designing the cavity geometry to promote attached, streamlined flow patterns, the system achieves both cooling effectiveness and particulate mitigation without depending on chaotic turbulence to prevent deposition.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The cavity geometry itself acts as an intermediary element that mediates between the cooling requirement and the particulate deposition problem. The specific dimensional ratios and curved surfaces of the cavity serve as a flow conditioning device, transforming the cooling airflow into a pattern that simultaneously protects the heat shield and minimizes particulate accumulation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If cooling airflow velocity is increased to reduce particulate accumulation, then durability is improved, but the energy consumption and thermal stresses on the structure increase

Engineering Contradiction:
Improvecomponent durabilityVSAvoidcooling air energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the flow regime parameters from high-velocity turbulence to moderate-velocity laminar flow. By adjusting the cavity geometry to promote streamlined flow, the system achieves effective particulate mitigation at lower airflow velocities, reducing the energy required to drive the cooling system while maintaining component durability.

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 approach effectively reduces airflow speed loss and particulate collection on heat shield panels, maintaining cooling efficiency and preventing blockages, thus enhancing the durability and performance of the combustor components.

Implementation Method 1

direct at least one of the cooling airflows to a second surface of the heat shield panel that is opposite the first surface such that the cooling airflows impinge upon the second surface

Methodology Applied
Scientific EffectImpingement cooling: Convection

Implementation Method 2

Particulates in the air used to cool these structures may inhibit cooling of the heat shield and reduce durability. Particulates, in particular atmospheric particulates, include solid or liquid matter suspended in the atmosphere such as dust, ice, ash, sand and dirt.

Methodology Applied
Scientific EffectTurbulent aerodynamics: Turbulence

Data Source

PatentEP3502564B1Combustor shell mitigating particulate accumulation on the bulkhead of a gas turbine engine
Publication Date: 2022.06.29 RTX CORP
  • EP3502564B1 patent drawingFigure 1
  • EP3502564B1 patent drawingFigure 2
  • EP3502564B1 patent drawingFigure 3A

AI summary

A gas turbine engine component assembly (100) comprising: a first component (600) having a first surface (610), a second surface (620) opposite the first surface, a first cooling hole (307) located in a first section (618) of the first component extending from the second surface to first surface, and a second cooling hole (307) located in a second section (622) of the first component extending from the second surface to first surface; a second component (400) having a first surface (410) and a second surface (420), the first surface of the first component and the second surface of the second component defining a cooling channel (390) therebetween in fluid communication with the cooling holes for cooling the second surface of the second component; wherein the first cooling hole is configured to direct at least one of the airflow (590) and the particulate (592) to impinge upon the second surface of the second component at first directional flow angle (θ1).