Optical Turbine Blade Damage Detection via Light Scattering

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Solution Overview

Problem

Current methods for detecting damage in turbomachine rotor blades, especially from smaller foreign object debris, are inadequate as they often fail to detect subtle changes visually and require regular inspections, which can be time-consuming and inefficient.

Innovation Solution

A damage detection system that uses emitters to emit light pulses along an emission axis intersecting the rotor blades and receivers to collect scattered light returns, analyzing amplitude changes to identify blade damage, with a controller processing data to output indications of damage based on predefined criteria, allowing for real-time monitoring during turbomachine operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visual inspection methods are used to detect blade damage, then the system is simple to operate, but small damage from foreign object debris cannot be detected

Engineering Contradiction:
Improvedamage detection capabilityVSAvoidinspection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces visual inspection methods with an optical measurement system using laser emitters and photodetector receivers. The system uses light scattering principles to detect blade surface changes, substituting mechanical/visual examination with optical field-based detection that can identify subtle damage from foreign object debris.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces light scattering as an intermediary mechanism between the blade surface and detection system. By analyzing how light scatters off the blade surface, the system indirectly detects damage that would be invisible to direct visual inspection, using light interaction patterns as a mediator to reveal hidden defects.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If regular manual inspections are performed to detect blade damage, then the inspection method is simple, but it is time-consuming and reduces productivity

Engineering Contradiction:
Improvedamage detection reliabilityVSAvoidoperational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent enables continuous monitoring of blade conditions during turbine operation rather than requiring periodic shutdowns for inspection. The optical system continuously emits light pulses and analyzes scattered light returns, providing uninterrupted detection capability that maintains operational continuity while ensuring blade integrity.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system allows the turbine to monitor its own blade conditions during normal operation without requiring external inspection intervention. The optical sensors are integrated into the turbine structure, enabling the machine to self-diagnose blade damage autonomously during operation, eliminating the need for separate manual inspection processes.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If visual inspection is used for blade damage detection, then no complex equipment is needed, but subtle damage changes remain undetected

Engineering Contradiction:
Improvedamage detection sensitivityVSAvoiddetection complexity
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent transitions from two-dimensional visual surface inspection to three-dimensional optical field analysis. By measuring light scattering patterns in multiple dimensions (intensity, angle, timing), the system captures comprehensive blade surface information that reveals subtle damage invisible to conventional visual methods.

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

Solution Approach 2:

The patent detects damage by measuring changes in light scattering parameters (intensity, distribution, timing) rather than relying on visual appearance. When blade surface geometry changes due to damage, the scattering parameters change accordingly, providing a sensitive quantitative measure of damage that is independent of visual detectability.

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

Enables the detection of blade damage that would otherwise go undetected, providing real-time monitoring and reducing the need for frequent inspections by analyzing light amplitude changes from back scatter, forward scatter, and side scatter, thus improving operational efficiency and maintenance timing.

Implementation Method 1

The receiver has a first field of view intersecting the emission axis to define a first interrogation volume through which the plurality of blades rotates during operation of the turbomachine. The system collects, at the receiver, a plurality of light returns scattered by the plurality of blades within the interrogation volume.

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP4184142B1Optical turbine engine blade damage detector
Publication Date: 2024.06.26 RTX CORP
  • EP4184142B1 patent drawingFigure 1
  • EP4184142B1 patent drawingFigure 2
  • EP4184142B1 patent drawingFigure 3A~3B

AI summary

A damage detection system (10) includes one or more emitters (20), one or more receivers (22), and a controller (24). Emitters (20) are arranged to transmit continuous beam or intermittent light pulses toward rotor blades (16) during operation of a turbomachine (12). Light returns collected at the receivers (22) define a light return amplitude profile. The controller (24) analyzes the light return amplitude profile to identify light amplitude changes indicative of one or more damaged blades (16). When the light return profile satisfies one or more damage criteria, the controller (24) outputs an indication of blade damage to another turbomachine controller (24), system (10), or display.