Showerhead Fuel Nozzle Layout for Mixing and Flame Anchoring Control
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Solution Overview
Problem
Existing fuel nozzles for turbine engines lack efficient fuel and air distribution designs that optimize combustion efficiency and prevent flame anchoring, leading to potential operational inefficiencies and safety risks.
Innovation Solution
A fuel nozzle design featuring multiple fuel and air passages arranged in concentric arrays with specific trajectories and swirl directions, including a concave nozzle face and recess, to enhance fuel and air mixing and distribution within the combustion chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fuel nozzle designs are used, then structural simplicity is maintained, but combustion efficiency is insufficient and flame anchoring occurs
Solution Approach 1:
The fuel nozzle is segmented into multiple functional zones with distinct passage types: central fuel passages for primary fuel delivery, annular fuel passages for secondary fuel distribution, and air passages for oxidizer supply. Each segment serves a specific combustion function, enabling efficient fuel-air mixing while preventing flame anchoring through distributed outlet arrangements.
Solution Approach 2:
Different regions of the fuel nozzle are assigned different functional qualities: the central region contains fuel passages for core combustion, the annular region contains additional fuel and air passages for peripheral combustion zones. This local differentiation optimizes combustion efficiency in each zone while maintaining overall system reliability.
2Reliability
If fuel and air passages are arranged in multiple concentric arrays, then fuel-air mixing is optimized, but manufacturing complexity increases
Solution Approach 1:
The fuel nozzle employs a nested concentric array structure where central fuel passages are surrounded by annular fuel passages, which are in turn surrounded by air passages. This nesting arrangement optimizes fuel-air mixing by creating controlled flow layers while the rotational symmetry of the concentric design facilitates manufacturing through single-sided machining operations.
Solution Approach 2:
While the overall structure is symmetric, the internal passage trajectories exhibit controlled asymmetry with radial, tangential, and axial components. This asymmetric trajectory design within the symmetric framework optimizes mixing efficiency while allowing standard manufacturing techniques to be applied to the external geometry.
3Reliability
If passage trajectories include radial and tangential components, then flame anchoring is reduced, but passage design complexity increases
Solution Approach 1:
The passage trajectories are designed with dynamic flow characteristics that switch between radial, tangential, and axial directions at different nozzle sections. This dynamic trajectory design prevents flame anchoring by creating turbulent mixing zones that disrupt stable flame attachment, while the systematic progression of direction changes follows manufacturable path patterns.
4Productivity
If multiple fuel outlet arrays are used, then combustion efficiency improves, but device complexity increases
Solution Approach 1:
The fuel outlets are segmented into multiple concentric arrays: a central array of fuel outlets, an intermediate annular array of fuel outlets, and an outer annular array of air outlets. Each array is optimized for specific combustion requirements, improving overall combustion efficiency while the concentric arrangement maintains manufacturing simplicity through rotational symmetry.
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
Improves combustion efficiency by optimizing fuel and air mixing, reducing flame anchoring, and enhancing operational safety through improved fuel-air interaction and distribution patterns.
Implementation Method 1
multiple fuel and air passages arranged in concentric arrays with specific trajectories and swirl directions
Data Source
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AI summary
A fuel nozzle (84) is provided that includes a fuel circuit and an air circuit. The fuel circuit includes a fuel cavity and a plurality of first fuel passages (130A). The first fuel passages (130A) respectively extend within the fuel nozzle (84) from the fuel cavity to a plurality of first fuel outlets (144A) disposed at a distal end (90) of the fuel nozzle (84). The first fuel outlets (144A) are arranged circumferentially about a nozzle centerline (88) in a first fuel outlet array (146A). The air circuit includes a plurality of air passages (156) that respectively extend within the fuel nozzle (84) to a plurality of air outlets (166) disposed at the distal end (90). The air outlets (166) are arranged circumferentially about the nozzle centerline (88) in an air outlet array.