Collinear Optical Sensor Packaging for Gas Turbine Blade Detection

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Solution Overview

Problem

Placing optical probes in the gas path of gas turbine engines is challenging due to limited space and the need to minimize disturbances to the gas flow path, making on-board optical inspection for detecting damaged blades difficult.

Innovation Solution

A collinear light source and optical sensor packaging is integrated into a single unit, positioned within the fan case, with a lens, beam splitter, and optical sensor aligned along a common optical axis, allowing for minimal space usage and effective imaging of blades while minimizing disruption to the gas flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If optical probes are placed in the gas path to detect damaged blades, then detection capability is improved, but space requirements increase and gas flow disturbance worsens

Engineering Contradiction:
Improveblade damage detection capabilityVSAvoidspace occupied in fan case
Core Design Contradiction:
Difficulty of detecting and measuringVSArea of stationary object

Solution Approach 1:

The patent combines the light source and optical sensor into a single integrated packaging unit that shares a common optical axis. This merging of previously separate components into one compact assembly reduces the total space required in the fan case while maintaining full detection capability for blade damage through the integrated optical system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The optical pipe is configured to extend through the fan case wall into the gas flow path, utilizing the dimensional space available at the case boundary rather than requiring additional internal volume. This approach allows optical access to the gas path without consuming valuable internal space within the fan case.

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

2Difficulty of detecting and measuring

If optical probes are placed in the gas path to detect damaged blades, then detection capability is improved, but gas flow disturbance increases

Engineering Contradiction:
Improveblade damage detection capabilityVSAvoidgas flow path disturbance
Core Design Contradiction:
Difficulty of detecting and measuringVSObject-generated harmful factors

Solution Approach 1:

The optical pipe is positioned to extend through the fan case wall, extracting the optical components from the main gas flow path while maintaining optical access to the blades. The light source and sensor are located outside the primary gas flow, with only the optical path penetrating into the flow area, thereby minimizing flow disturbance while preserving detection capability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If light source and optical sensor are positioned separately to achieve optimal imaging, then detection precision is improved, but device complexity increases

Engineering Contradiction:
Improveblade imaging precisionVSAvoidoptical system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The light source and optical sensor are merged into a single integrated packaging with a shared optical axis, simplifying the overall system architecture. This integration maintains precise optical alignment for high-quality blade imaging while reducing the number of separate components, mounting requirements, and alignment procedures needed compared to traditionally separate installations.

Inventive Principle:
Principle #5Merging (Combining)

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

This configuration enables efficient detection of blade damage with reduced interference to the gas flow, using a single hole and protecting the light source and sensor from debris, while allowing for real-time monitoring and protection mechanisms like shutters and pivots.

Implementation Method 1

The beam splitter may be a dichroic mirror. The optical sensor may be positioned to capture an image reflected by the beam splitter.

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

The lens may be positioned within the fan case. The beam splitter may be aligned with the lens.

Methodology Applied
Scientific EffectLens focusing: Lens

Data Source

PatentEP4700212A1Light source and optical sensor packaging for gas turbines
Publication Date: 2026.02.25 RTX CORP
  • EP4700212A1 patent drawingFigure 1A
  • EP4700212A1 patent drawingFigure 1B
  • EP4700212A1 patent drawingFigure 2

AI summary

An apparatus may include a fan case (130) and an optical pipe (102a). The fan case (130) may define a gas flow path (132). The optical pipe (102a) may have a portion extending through the fan case (130) into the gas flow path (132). The optical pipe (102a) may include a lens (104), a beam splitter (106), a light source (108), and an optical sensor (110). The lens (104) may be positioned within the fan case (130). The beam splitter (106) may be aligned with the lens (104). The light source (108) may be positioned on a first side of the beam splitter (106). The optical sensor (110) may be positioned on a second side of the beam splitter (106) in a manner that an optical axis (111) of the optical sensor (110) is colinear with an optical axis (109) of the light source (108) at the lens (104).