Bladed Component Mistuning Measurement Rig

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Solution Overview

Problem

Current systems for testing integrally bladed rotors (IBRs) face challenges with smaller IBRs, particularly in achieving higher measurement accuracy and efficient surface preparation, as they often require more precise location identification and handling of higher frequency responses.

Innovation Solution

A rig with an off-axis vibrometer and vision system configuration that allows precise location identification of the laser beam on airfoil blades, enabling accurate measurement of sound energy effects, and adjustable positions for the speaker and vibrometer to accommodate smaller IBRs and various rotational configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an on-axis vibrometer system with reflective tape is used for large IBRs, then measurement capability is achieved, but measurement precision and ease of operation deteriorate for smaller IBRs due to higher frequencies and greater accuracy requirements

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidsurface preparation burden
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces the mechanical/optical system requiring reflective tape (mechanical surface preparation) with an acoustic field-based measurement system. The acoustic vibrometer measures blade vibrations through sound wave interaction without requiring physical surface markers, thereby eliminating the burdensome surface preparation process while maintaining measurement capability for high-frequency responses of smaller IBRs

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

Solution Approach 2:

The patent changes the measurement parameter from optical reflection (requiring tape) to acoustic field interaction. By using acoustic waves at specific frequencies that resonate with blade vibrations, the system achieves precise measurements without physical surface modifications, resolving the contradiction between measurement precision and ease of operation

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the speaker position is fixed relative to the IBR, then the system is simple, but adaptability to different IBR sizes and configurations is reduced

Engineering Contradiction:
Improveaccommodation of different IBR sizesVSAvoidrig configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic positioning capabilities where the speaker and vibrometer can be moved to different locations around the IBR. This dynamic configuration allows the same rig to adapt to various IBR sizes and rotational setups, achieving versatility without requiring multiple fixed systems. The movable components enable adjustment of measurement planes and speaker positions to match different component geometries

Inventive Principle:
Principle #15Dynamics

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 high-frequency measurements with improved accuracy and reduced surface preparation burdens, effectively assessing mistuning in smaller IBRs and potentially other airfoil components.

Implementation Method 1

A speaker is moved under that blade, and a sound energy is applied to one blade

Methodology Applied
Scientific EffectSound energy: Sound

Implementation Method 2

The laser then indexes to measure every other blade, based upon the sound energy put into each blade

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 3

A rig for measuring bladed component mistuning using an off-axis vibrometer and vision system configuration that allows precise location identification of the laser beam on airfoil blades

Methodology Applied
Scientific EffectLaser Doppler vibrometry: Laser Doppler Vibrometry

Data Source

PatentEP2485031B1Rig for measuring bladed component mistuning
Publication Date: 2015.12.16 UNITED TECH CORP
  • EP2485031B1 patent drawingFigure 1~2
  • EP2485031B1 patent drawingFigure 3

AI summary

A rig (20) for studying a component (22) has a component (36) support for mounting the component (22). A speaker (30) applies sound energy to airfoils (24; 26) in the component (22). A vibrometer (38) studies the effect of the applied sound on the airfoils (24; 26). At least two of the vibrometer (38), the component support (36), and the speaker (30) are rotatable relative to each other. In a separate feature, a vibrometer (38) for studying the effect of sound energy on airfoils (24; 26) in a component (22) is provided with a vision system (40). The vision system (40) is operable to identify the exact location at which the laser is studying the effect on the airfoil (24; 26). Methods are also disclosed.