SAW Sensor Assembly for Gas Turbine Engine Monitoring

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Solution Overview

Problem

Existing gas turbine engine monitoring technologies face challenges in effectively sensing the conditions of rotatable components due to the complex and dynamic nature of their operation, particularly in accurately measuring temperature, strain, torque, vibration, and pressure on contoured surfaces.

Innovation Solution

A sensor assembly is integrated onto the gas turbine engine components, featuring a substrate layer made of piezoelectric material with transducers and an antenna, which communicates through a clearance gap to a controller, allowing for the detection of changes in frequency and amplitude of mechanical signals caused by component conditions, providing real-time data on the component's state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional sensing technologies are used on rotatable gas turbine engine components, then the basic monitoring function is provided, but measurement precision and reliability are insufficient due to the complex and dynamic operating conditions

Engineering Contradiction:
Improvemeasurement precisionVSAvoidreliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces traditional mechanical sensing systems with acoustic wave-based sensing. Surface acoustic wave (SAW) devices are used to detect temperature, strain, and pressure conditions on rotatable components. The acoustic waves propagate along the surface of the component and their characteristics change in response to environmental conditions, providing precise measurements without mechanical contact that would compromise reliability in dynamic environments.

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

Solution Approach 2:

The patent utilizes changes in acoustic wave parameters (frequency, amplitude, velocity) to detect changes in physical conditions. The SAW device measures temperature, strain, and pressure by detecting shifts in the acoustic wave characteristics. This parameter-based detection method enables high-precision measurement while maintaining reliability under complex operating conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If sensors are integrated onto contoured surfaces of rotatable components, then monitoring coverage is improved, but device complexity increases due to the need for conformal substrate layers and transducer integration

Engineering Contradiction:
Improvemonitoring coverageVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs thin flexible substrate layers that can be deposited onto contoured surfaces of rotatable components. These thin films conform to the complex geometry of the component surface, enabling sensor integration on curved and irregular surfaces. The flexible nature of the thin film substrate allows it to adapt to the contoured geometry without requiring complex rigid structures, thus improving monitoring coverage while managing device complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent transitions from planar sensor arrays to three-dimensional conformal sensor integration. By depositing substrate layers and transducers that follow the contours of the rotatable component, the sensing capability extends across the surface in multiple dimensions. This dimensional approach enables comprehensive monitoring coverage on complex geometries.

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

3Productivity

If real-time monitoring of component conditions is implemented, then operational efficiency and diagnostic capability are improved, but loss of time for data processing and communication increases

Engineering Contradiction:
Improveoperational efficiencyVSAvoiddata processing time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent implements self-powered sensing where the surface acoustic wave devices harvest energy from the engine's operational vibrations and thermal energy. The SAW sensors are passive devices that do not require external power sources, eliminating the need for complex power management systems. Data is transmitted wirelessly when the component is in service, enabling real-time monitoring without significant time loss for data processing.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent establishes a feedback loop where sensor data is continuously monitored and analyzed to provide real-time insights into component conditions. The system compares measured parameters against threshold values and provides immediate feedback for diagnostic purposes. This enables operational efficiency improvements through proactive maintenance decisions while minimizing data processing time through automated analysis.

Inventive Principle:
Principle #23Feedback

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 solution enables accurate and reliable monitoring of gas turbine engine components, reducing maintenance costs and improving operational efficiency by providing precise data on component conditions, which can be used for diagnostics and prognostics, and enhancing the reliability of the engine's performance.

Implementation Method 1

a substrate layer made of piezoelectric material with transducers

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

the substrate layer is responsive to one or more signals communicated from one of the at least one pair of transducers

Methodology Applied
Scientific EffectPiezoelectric response to mechanical stress: Piezoelectric Effect

Data Source

PatentEP3498986B1Sensor assembly for gas turbine engines
Publication Date: 2022.03.30 RTX CORP
  • EP3498986B1 patent drawingFigure 1
  • EP3498986B1 patent drawingFigure 2~4
  • EP3498986B1 patent drawingFigure 5

AI summary

A sensor assembly (62) for a gas turbine engine includes a substrate layer (64) formed on a localized surface (LS) of a rotatable gas turbine engine component (60), and at least one pair of transducers (66) deposited on the substrate layer (64).