Fuel Injector Assembly With High Shear Swirler

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Solution Overview

Problem

Existing fuel injector assemblies for turbine engines face challenges in improving fuel-air mixing and reducing combustor dynamics and undesirable combustor tones.

Innovation Solution

A fuel injector assembly with a high shear swirler configuration, featuring a multi-segment swirler with upstream, intermediate, and downstream segments, and a fuel injector nozzle that impinges fuel jets onto the swirler inner wall to form a thin fuel film, enhancing atomization through shear forces and optimized geometry for improved mixing and tone reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a conventional fuel injector assembly is used, then the structure is simple, but fuel-air mixing is insufficient and combustor tones are high

Engineering Contradiction:
Improvestructural simplicityVSAvoidfuel-air mixing efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The swirler is divided into multiple segments (upstream, intermediate, downstream) that can be assembled together, allowing for complex flow control functionality while maintaining manufacturing feasibility through modular construction

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different segments of the swirler have different vane configurations and geometries optimized for specific local functions - upstream segments create initial swirl, intermediate segments enhance mixing, and downstream segments control final flow characteristics, allowing each region to perform its specialized function

Inventive Principle:
Principle #3Local quality

2Productivity

If a high shear swirler with multi-segment configuration is implemented, then fuel-air mixing is improved, but device complexity increases

Engineering Contradiction:
Improvefuel-air mixing efficiencyVSAvoidswirler configuration complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The swirler is divided into multiple segments (upstream, intermediate, downstream) that can be assembled together, allowing for complex flow control functionality while maintaining manufacturing feasibility through modular construction

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multi-segment swirler configuration serves multiple functions simultaneously - creating swirl flow, enhancing fuel-air mixing, controlling combustion dynamics, and reducing combustor tones - all within a single integrated component assembly

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If fuel jets are impinged onto the swirler inner wall to form a thin fuel film, then atomization is enhanced, but manufacturing precision requirements increase

Engineering Contradiction:
Improveatomization qualityVSAvoidfuel film thickness control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The swirler inner wall features locally optimized geometry including specific curvature radii, surface roughness characteristics, and angular configurations that naturally control fuel film formation and thickness distribution, reducing reliance on tight manufacturing tolerances

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The design optimizes parameters such as swirl number, fuel injection pressure, and swirler geometry to achieve the desired thin fuel film formation through controlled physical processes rather than precise manufacturing alone

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

The assembly achieves improved fuel-air mixing and reduced combustion dynamics, leading to enhanced combustion efficiency and minimized combustor tones by optimizing fuel film thickness and air swirl velocities.

Implementation Method 1

A fuel injector nozzle is cantilevered from the fuel injector stem and projects along the axis into the inner passage. A tip of the fuel injector nozzle is disposed within the inner passage upstream of the inner nozzle outlet. The fuel injector assembly is configured such that a ratio of the axial distance D to the outer passage exit diameter Dsw-ex is between 0.50 and 0.75. Further, the fuel injector assembly is configured such that a ratio of the axial distance (D-d) to the outer passage exit diameter Dsw-ex is between 0.25 and 0.80, wherein d is a distance from the distal outer wall end to the distal inner wall end of the swirler. High shear swirler atomization enables improved fuel/air mixing and reduced combustion dynamics

Methodology Applied
Scientific EffectShear force: Shear Stress

Implementation Method 2

A fuel injector assembly with a high shear swirler configuration, featuring a multi-segment swirler with upstream, intermediate, and downstream segments

Methodology Applied
Scientific EffectSwirl flow: Vortex Ring

Implementation Method 3

enhancing atomization through shear forces and optimized geometry for improved mixing and tone reduction

Methodology Applied
Scientific EffectAtomization: Aerosol

Data Source

PatentEP3832207B1Fuel injector assembly
Publication Date: 2024.04.10 RTX CORP
  • EP3832207B1 patent drawingFigure 1
  • EP3832207B1 patent drawingFigure 2
  • EP3832207B1 patent drawingFigure 3

AI summary

An assembly is provided for a turbine engine. This assembly includes a swirler (64) and a fuel nozzle (154). The swirler (64) is configured with an outer wall (80), an inner wall (82), an outer passage (86) and an inner passage (84). The outer wall (80) circumscribes the inner wall (82) and extends axially along an axis (70) to a distal outer wall end (138). The inner wall (82) extends axially along the axis (70) to a distal inner wall end (118) that is axially recessed within the swirler (64) from the distal outer wall end (138). The outer passage (86) is formed by and radially between the inner wall (82) and the outer wall (80). The inner passage (84) is formed by and radially within the inner wall (82). The fuel nozzle (154) projects into the inner passage (84). The fuel nozzle (154) is configured with a plurality of orifices (158) axially aligned with the inner wall (82) and arranged circumferentially about the axis (70).