Turbine Rim Thermal Insulation via Segmented Studs

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Solution Overview

Problem

The existing turbine engine designs face significant risks of deterioration due to excessive heat conduction from hot gas flow, leading to high temperatures at the circumferential rim and outer casing, which can exceed the material's acceptable limit, causing potential damage.

Innovation Solution

A turbine stage design featuring a rotor wheel inside a sectorized ring with radially spaced annular cavities and studs to reduce the contact area between the ring sector and the circumferential rim, creating a thermally insulating space and using radial positioning means to minimize friction and wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the contact area between the circumferential rim and ring sector is large, then the structural attachment is strong, but the heat conduction to the outer casing becomes excessive

Engineering Contradiction:

Improvestructural attachment strengthVSAvoidtemperature of circumferential rim

Core Design Contradiction:

StrengthVSTemperature

Solution Approach 1:

The invention segments the contact interface by introducing radial studs that create discrete contact points instead of a continuous contact surface. The bottom wall of the annular cavity is spaced apart from the circumferential rim, with only the studs providing contact. This segmentation reduces the overall contact area while maintaining localized attachment strength through the studs, thereby reducing heat conduction to the outer casing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention applies local quality by concentrating the attachment function at specific locations (the studs) rather than distributing it across the entire bottom wall. The studs provide localized mechanical attachment while the spaced-apart configuration maintains thermal insulation in the non-contact regions. This localizes the thermal conduction paths to only the stud contact points.

Inventive Principle:

Principle #3Local quality

2Temperature

If the bottom wall is spaced apart from the circumferential rim, then heat conduction is reduced, but the ring sector positioning stability may be compromised

Engineering Contradiction:

Improvetemperature of circumferential rimVSAvoidpositioning stability of ring sector

Core Design Contradiction:

TemperatureVSStability of the object's composition

Solution Approach 1:

The positioning stability is maintained through segmented contact points provided by the radial studs. Although the bottom wall is spaced apart from the circumferential rim, the studs provide discrete attachment points that constrain the ring sector's position. This segmentation allows thermal insulation while preserving mechanical stability through the distributed stud contacts.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The radial studs act as intermediaries between the ring sector's bottom wall and the circumferential rim. They provide the necessary mechanical connection and positioning stability while minimizing thermal conduction due to their small contact area compared to a full surface contact. The studs mediate between the conflicting requirements of mechanical stability and thermal insulation.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Temperature

If radial positioning means are added to reduce contact area, then heat conduction is limited, but device complexity increases

Engineering Contradiction:

Improvetemperature of circumferential rimVSAvoidcomplexity of positioning means

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The radial positioning means are implemented as simple radial studs that segment the contact interface. These studs are straightforward structural elements that can be easily manufactured and integrated into the ring sector design. The segmentation approach achieves heat conduction reduction without requiring complex positioning mechanisms, maintaining relative simplicity in the device design.

Inventive Principle:

Principle #1Segmentation

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 design effectively reduces the heating of the circumferential rim and outer casing by 40°C, minimizing material degradation and ensuring proper positioning and sealing while reducing operational wear.

Implementation Method 1

the bottom wall of the annular cavity of the ring sector remains radially spaced apart from the circumferential rim of the outer casing so as to provide a thermally insulating space between them

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

The contact area between the circumferential rim of the casing and each of the ring sectors is large, so a large fraction of the heat of the ring is conducted to the outer casing via the circumferential rim

Methodology Applied

Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentUS8961117B2Insulating a circumferential rim of an outer casing of a turbine engine from a corresponding ring sector

Publication Date: 2015.02.24 SAFRAN AIRCRAFT ENGINES SAS

AI summary

A turbine stage of a turbine engine, the stage including a rotor wheel mounted inside a sectorized ring carried by an outer casing, the outer casing including at least a circumferential rim housed in an annular cavity to attach a downstream end of the ring sector. A bottom wall of the annular cavity of the ring sector remains radially spaced apart from the circumferential rim of the outer casing to provide a thermally insulating space between them and includes a radial positioning mechanism acting on the circumferential rim.