Induction Heating Auxiliary Body for Turbine Blade Temperature Uniformity

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Solution Overview

Problem

Current induction brazing processes for coating blade tips in gas turbine engines suffer from inhomogeneous temperature distributions due to complex geometries, leading to overheating and high scrap rates, particularly at leading and trailing edges.

Innovation Solution

A device and method for inductive heating that includes a coil device generating a magnetic field and an auxiliary body positioned perpendicular to the magnetic field, creating an eddy current field to concentrate the magnetic field and enhance heating efficiency, with the auxiliary body's material properties adapted to the component for optimal heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If induction heating is applied to complex geometry components like turbine blades, then local heating capability is achieved, but inhomogeneous temperature distribution occurs leading to overheating at leading and trailing edges

Engineering Contradiction:
Improvetemperature distribution uniformityVSAvoidcoating quality
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

A magnetic field distributor is introduced as an intermediary component between the induction coil and the turbine blade. This distributor mediates the magnetic field generation process, converting the non-uniform magnetic field from the coil into a uniform magnetic flux distribution across the blade surface, thereby achieving homogeneous temperature distribution during induction heating

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The magnetic field distributor changes the physical parameters of the magnetic field by providing a defined magnetic reluctance and flux path. Through parameter optimization of the distributor geometry and material properties, the magnetic field density is equalized across different regions of the blade, eliminating hot spots at leading and trailing edges

Inventive Principle:
Principle #35Parameter changes

2Power

If strong magnetic fields are generated for effective heating, then heating efficiency improves, but thermal load on the component increases causing damage

Engineering Contradiction:
Improveheating powerVSAvoidthermal load
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The magnetic field distributor creates locally optimized magnetic flux paths that concentrate magnetic field strength precisely where heating is needed while limiting field penetration into sensitive regions. This local quality control allows high heating power to be applied selectively without imposing excessive thermal load on the entire component

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The magnetic field distributor is pre-configured with optimized geometry and material properties before the heating process begins. This preliminary design ensures that when the induction coil generates strong magnetic fields, the distributor immediately channels and regulates the flux to achieve efficient heating while preventing harmful thermal accumulation

Inventive Principle:
Principle #10Preliminary action

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 approach achieves a more uniform temperature distribution and reduces overheating, improving the reproducibility and efficiency of the coating process while minimizing thermal load on the component.

Implementation Method 1

An alternating magnetic field is generated by means of the coil device, which generates an eddy current field at least in the region of the component to be heated

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

An alternating magnetic field is generated by means of the coil device, which generates an eddy current field at least in the region of the component to be heated

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Implementation Method 3

An alternating magnetic field is generated by means of the coil device, which generates an eddy current field at least in the region of the component to be heated

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 4

an auxiliary body which is designed not to be joined to the component (10) and to be arranged adjacent to the component in the magnetic field of the coil device in such a way that the auxiliary body is opposite the component in a direction which is perpendicular or substantially perpendicular to the direction of a magnetic field

Methodology Applied
Scientific EffectMagnetic field concentration: Magnetic Field

Data Source

PatentEP2422581B1Method and apparatus for induction-heating a part
Publication Date: 2013.06.12 MTU AERO ENGINES GMBH
  • EP2422581B1 patent drawingFigure 1~2
  • EP2422581B1 patent drawingFigure 3~4

AI summary

An apparatus (20) for induction-heating at least one zone (12, 14) of a part (10) comprises a coil device (30) for generating a magnetic field in at least said zone (12, 14) of the part (10), and an auxiliary member (40) to be disposed adjacent to the part (10), within the magnetic field of the coil device (30), in such a way that the auxiliary member (40) faces the part (10) in a direction running perpendicular or substantially perpendicular to the direction of a magnetic field that the coil device (30) can generate in the zone between the part (10) and the auxiliary member (40).