Oblong Swirler Exit Flame Alignment Combustor Liner

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Solution Overview

Problem

Conical flame patterns produced by traditional swirlers in gas turbine engines often misalign with the annular shape of the combustor, leading to 'touchdown' on the liners, which reduces the service life of the combustor and turbine.

Innovation Solution

A swirler design with a circumferentially elongated exit, positioned between inner and outer shrouds, to create a more aligned and distributed flame pattern, reducing contact with the combustor liners.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a traditional circular outlet swirler is used, then the fuel and air mixture spray is produced, but the conical flame pattern does not align with the annular combustion chamber shape, causing flame touchdown on the liners

Engineering Contradiction:
Improveflame pattern shapeVSAvoidcombustor service life
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The patent applies asymmetry by changing the swirler outlet from a traditional circular shape to an oblong shape with circumferential width greater than radial width. This asymmetric geometry transforms the conical flame pattern into a circumferentially elongated pattern that aligns with the annular combustion chamber, preventing flame touchdown on the liners and improving combustor reliability

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent implements parameter changes by modifying the outlet dimensions of the swirler vanes. Specifically, the circumferential width of the outlet is made greater than the radial width, creating an oblong exit geometry. This parameter change directly alters the flame pattern shape from conical to circumferentially elongated, resolving the misalignment issue with the annular combustion chamber

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If a conical spray pattern is produced by the swirler, then fuel and air mixing occurs, but the flame contacts the inner and outer liners of the combustor

Engineering Contradiction:
Improvefuel-air mixingVSAvoidflame touchdown
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The asymmetric oblong outlet geometry redistributes the fuel-air mixture flow circumferentially around the annular combustion chamber. This asymmetric design maintains effective mixing while directing the flame pattern away from the liners, eliminating the harmful touchdown effect

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent transitions the flame pattern from a three-dimensional conical shape to a more two-dimensional circumferentially elongated pattern by increasing the circumferential width of the outlet. This dimensional change distributes the flame across the annular space, preventing concentration at the liner surfaces

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 elongated swirler exit produces a circumferentially elongated flame pattern, minimizing flame touchdown and enhancing the durability and service life of the combustor by reducing hot spots.

Implementation Method 1

the swirlers create turbulence in the combustion chamber and mix the combustion air and fuel

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

A swirler design with a circumferentially elongated exit, positioned between inner and outer shrouds, to create a more aligned and distributed flame pattern

Methodology Applied
Scientific EffectGeometry: Geometry

Data Source

PatentEP3431876B1Swirler for combustor of gas turbine engine
Publication Date: 2021.10.20 RTX CORP
  • EP3431876B1 patent drawingFigure 1
  • EP3431876B1 patent drawingFigure 2
  • EP3431876B1 patent drawingFigure 3

AI summary

A combustor (50) for a gas turbine engine includes an annular combustor shell, the annular combustor shell defining a combustion chamber (62), and a fuel injector (70) extending at least partially into the combustion chamber, and configured to deliver a flow of fuel (76) and a flow of combustion air (78) into the combustion chamber for combustion. The fuel injector includes a swirler (74) with a swirler exit (94) having a circumferential width (96) along a circumferential axis greater than a radial width (98) along a radial axis. A swirler for a gas turbine engine includes a swirler entrance (92) and a swirler exit (94). The swirler exit has a circumferential width along a curvilinear circumferential axis greater than a radial width along a radial axis.