Multi-directional Optical Probe for Gas Turbine Flame Tracking
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Solution Overview
Problem
Existing optical flame sensors for gas turbine engines struggle to accurately observe and track a moving flame front, leading to inconsistent measurements and errors in determining flame characteristics, especially during extreme throttle operations.
Innovation Solution
An optical sensor system with a fuel injector and an optical probe featuring multiple optical fiber bundles and a shaped lens, providing a multi-directional field of view, is designed to track the movement of a flame within the combustion chamber, using a central and circumferentially arranged fiber bundles to maintain accurate flame observation and control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single-direction optical sensor is used to observe the flame, then the device complexity is low, but the measurement precision deteriorates because the flame front moves out of the field of vision
Solution Approach 1:
The optical sensor is divided into multiple optical fiber bundles arranged in different directions. Each bundle observes a specific sector of the combustion chamber, allowing the system to track a moving flame front by selecting data from the appropriate bundle based on flame position, thereby maintaining measurement precision without requiring a single complex omnidirectional sensor
Solution Approach 2:
The multi-directional optical fiber bundle array provides multiple fields of view simultaneously, enabling the sensor system to observe flame characteristics from multiple directions and track flame movement throughout the combustion chamber. This multi-functional arrangement allows accurate flame observation regardless of flame position or throttle operation conditions
2Measurement precision
If the optical probe uses more optical fiber bundles to track moving flame, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
Different optical fiber bundles are positioned to observe specific sectors of the combustion chamber with optimized field of view angles. Each bundle is tailored to capture flame characteristics from its specific direction, allowing the system to maintain high measurement precision for flame characteristics while managing device complexity through targeted local observation zones
Solution Approach 2:
The system processes signals from multiple optical fiber bundles and identifies which bundle is currently observing the flame front. By selecting and using data only from the active bundle(s), the system achieves accurate flame tracking without requiring all bundles to operate simultaneously, effectively managing data processing complexity while maintaining measurement precision
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 system enables real-time, accurate tracking and control of the flame, improving engine efficiency by stabilizing combustion and reducing the risk of hardware damage from combustion instability.
Implementation Method 1
an optical probe located within the nozzle body along a central axis thereof for observing combustor flame radiation
Implementation Method 2
A shaped lens is supported at the distal end of the probe and it is configured to provide a multi-directional field of view for the optical fiber bundles
Implementation Method 3
Combustion instability is generally understood as high amplitude pressure oscillations that occur as a result of the turbulent nature of a combustion process and the large volumetric energy release within the combustion chamber
Data Source
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AI summary
A fuel injector, 20, for a gas turbine engine is disclosed which includes a nozzle body, 28, for issuing fuel and air into a combustor, 30, and an on-axis optical probe, 50, located within the nozzle body, 28, for observing combustor flame radiation, wherein the optical probe, 50, includes a plurality of optical fiber bundles, 60a - 60g, extending to a distal end of the probe, 50, and a shaped lens, 56, is supported at the distal end of the probe, 50, to provide a multi-directional field of view of combustion characteristics and properties in an operating gas turbine engine combustor.