Windback Heat Shield for Gas Turbine Thermal Gradient Management

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Solution Overview

Problem

Current heat shield designs for gas turbine engines are inadequate in managing thermal gradients and temperature distribution between inner and outer cases, particularly in areas adjacent to bleed manifolds, leading to inefficient thermal protection and potential mechanical stress.

Innovation Solution

A heat shield design with a windback shape and a larger air space between the inner and outer cases, where the second end of the heat shield curves in an upstream direction and includes a foot for secure attachment, providing axial and radial motion tolerance to accommodate thermal expansion and enhance thermal protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a heat shield is installed adjacent to the inner case with connections at radially inward and radially outward locations, then thermal protection is provided, but thermal gradients and temperature distribution between inner and outer cases are not effectively managed

Engineering Contradiction:
Improvetemperature distributionVSAvoidthermal protection efficiency
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The heat shield employs a windback configuration where the second end curves in an upstream direction, creating a curved protective surface that better follows the thermal flow patterns and provides enhanced thermal protection compared to straight-edge configurations

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention introduces a larger air space between the inner and outer cases, adding a dimensional buffer zone that improves thermal isolation and manages temperature distribution more effectively than conventional minimal-spacing designs

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

2Stability of the object's composition

If the heat shield is rigidly connected to both inner and outer cases, then structural stability is maintained, but differential thermal expansion causes mechanical stress

Engineering Contradiction:
Improvestructural stabilityVSAvoidmechanical stress
Core Design Contradiction:
Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The heat shield connection system transitions from rigid fixed connections to a dynamic configuration where the second end can move relative to the outer case, allowing the structure to adapt to thermal expansion and contraction while maintaining overall stability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the connection parameter from fixed rigid attachment to a movable configuration, enabling the heat shield to accommodate dimensional changes during thermal cycling and reducing mechanical stress accumulation

Inventive Principle:
Principle #35Parameter changes

3Volume of stationary object

If the air space between inner and outer cases is minimized, then structural compactness is achieved, but thermal protection and motion tolerance are reduced

Engineering Contradiction:
Improvestructural compactnessVSAvoidthermal protection
Core Design Contradiction:
Volume of stationary objectVSReliability

Solution Approach 1:

The invention strategically increases the air space volume between inner and outer cases, creating a larger thermal buffer zone that enhances thermal protection and provides room for thermal expansion without compromising overall engine compactness

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

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

The improved heat shield design effectively reduces thermal gradients and mechanical stress by allowing differential thermal expansion between the outer and inner cases, enhancing the thermal protection of both cases and maintaining structural integrity.

Implementation Method 1

allowing differential thermal expansion between the outer and inner cases

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

providing an air space between the heat shield and the inner case

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3011155B1Heat shield
Publication Date: 2020.12.30 RTX CORP
  • EP3011155B1 patent drawingFigure 1
  • EP3011155B1 patent drawingFigure 2
  • EP3011155B1 patent drawingFigure 3

AI summary

A heat shield includes a first end configured to connect to an inner engine case at an inner connecting point, and a second end configured to connect to an outer engine case at an outer connecting point. The heat shield also includes a bulge extending in an aft direction from a radially upstream portion. A compressor section and a gas turbine engine including the heat shield are also disclosed.