Fuel Nozzle Assembly with Circumferential Stops

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Solution Overview

Problem

Fuel nozzles in gas turbine engines are susceptible to coking due to high temperature environments, which can restrict fuel flow and increase maintenance burdens, and existing designs struggle to maintain efficient fuel flow dynamics.

Innovation Solution

A fuel nozzle assembly comprising a proximal and distal member with mating portions and stops that ensure axial engagement and fluid flow communication, along with a circumferentially broader interconnecting conduit to tolerate misalignment and prevent coking, featuring a male-female configuration with circumferential stops for precise alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If a two-component fuel nozzle assembly is used to achieve small diameter and sufficient length, then the fuel conduit dimensions are improved, but the alignment precision and fluid flow communication between components become problematic

Engineering Contradiction:
Improvefuel conduit lengthVSAvoidalignment precision
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

The patent introduces intermediary alignment features (stops, mating portions with circumferential alignment) that mediate between the proximal and distal members during assembly. These features ensure precise relative positioning without requiring high-precision machining of the entire assembly, thus enabling long fuel conduits while maintaining alignment precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The fuel nozzle is segmented into proximal and distal members that can be manufactured separately and then assembled. This segmentation allows each component to be optimized independently while the alignment features ensure proper fluid flow communication when assembled, resolving the contradiction between achieving sufficient length through assembly and maintaining manufacturing precision.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If traditional fuel nozzle assemblies are used in high temperature environments, then the structural simplicity is maintained, but coking occurs and fuel flow is restricted

Engineering Contradiction:
Improveassembly structure simplicityVSAvoidfuel flow reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent changes the geometric parameters of the fuel conduit, specifically introducing an annular groove and optimizing the conduit diameter and length ratios. These parameter changes improve fuel flow dynamics, prevent coking in high-temperature environments, while maintaining a relatively simple two-component assembly structure.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If precise circumferential alignment is achieved through stops, then fluid flow communication is ensured, but the assembly complexity increases

Engineering Contradiction:
Improvecircumferential alignment precisionVSAvoidassembly feature complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the alignment function with the structural components themselves. The stops and mating portions are integrated into the proximal and distal members rather than being separate features, ensuring precise circumferential alignment while minimizing additional assembly complexity. The alignment features are combined with the fuel conduit structure to achieve both precision and simplicity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3974726B1Fuel nozzle and associated method of assembly
Publication Date: 2023.09.13 PRATT & WHITNEY CANADA CORP
  • EP3974726B1 patent drawingFigure 1
  • EP3974726B1 patent drawingFigure 2A~2B
  • EP3974726B1 patent drawingFigure 2C~2D

AI summary

The fuel nozzle (20) can have a proximal member (26) having a first mating portion (36) defined around an assembly axis (28), a first fluid conduit (50) internal to the proximal member (26) and spaced apart from the assembly axis (28), and a first stop (58) facing a first circumferential direction; and a distal member (24) having a second mating portion (34) configured for axial engagement with the first mating portion (36) along the assembly axis (28), a second stop (60) facing a second circumferential direction, the second circumferential direction opposite the first circumferential direction and configured to abut against the first stop (58) when the distal member (24) and proximal member (26) are axially engaged to one another in a predetermined relative circumferential alignment.