Gas Turbine Containment Ring With Foam Energy Absorption

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Solution Overview

Problem

Existing gas turbine engines face challenges in effectively containing dislodged blades during failures, with hard wall containment systems experiencing high, concentrated forces and soft wall systems causing significant bulges and design complications.

Innovation Solution

A casing design featuring axial hairpin features with radially extending portions and central connecting portions, filled with lightweight materials like potting compound or honeycomb, which absorb kinetic energy and redistribute containment forces, reducing peak stresses and allowing a more compact, lighter design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hard wall containment systems are used, then blade containment is effective, but high concentrated forces are experienced

Engineering Contradiction:
Improveblade containment effectivenessVSAvoidcontained force concentration
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent employs a foam-filled containment ring where the foam material (such as polyethylene foam) acts as a porous energy-absorbing medium. When a blade fails, the foam compresses and deforms, absorbing kinetic energy through its cellular structure while distributing forces across a larger volume rather than concentrating them at single points, thus maintaining containment effectiveness while reducing force concentration.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The containment ring combines multiple materials: a metallic outer structure providing structural integrity and a foam inner filling providing energy absorption. This composite construction allows the ring to withstand blade impact forces while the foam layer dissipates energy through compression, resolving the contradiction between effective containment and force concentration.

Inventive Principle:
Principle #40Composite materials

2Force

If soft wall containment systems are used, then force concentration is reduced, but significant bulges and design complications occur

Engineering Contradiction:
Improveforce distributionVSAvoidcontainment bulge
Core Design Contradiction:
ForceVSShape

Solution Approach 1:

The foam filling is strategically positioned only in the interior cavity of the containment ring, providing energy absorption where needed during blade impact while maintaining the ring's overall structural shape. The foam is contained within boundaries defined by the metallic ring structure, preventing uncontrolled bulging while still allowing localized compression to absorb impact forces.

Inventive Principle:
Principle #3Local quality

3Reliability

If traditional containment designs are used, then blade containment is achieved, but large keep-out zones and nacelle loft are required

Engineering Contradiction:
Improveblade containmentVSAvoidkeep-out zone
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The foam-filled containment ring is nested within the existing engine casing structure, utilizing the available internal volume efficiently. The ring is positioned to intercept blades within the existing design envelope, eliminating the need for additional external keep-out zones while maintaining effective containment capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

4Reliability

If traditional containment structures are used, then blade containment is effective, but heavier engine structure is required

Engineering Contradiction:
Improveblade containment effectivenessVSAvoidengine structure
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The foam material provides high energy absorption capacity relative to its weight, allowing the containment ring to be lighter than traditional solid metallic constructions while maintaining effective blade containment. The foam's cellular structure dissipates impact energy through compression without requiring excessive material mass.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The hybrid design combines lightweight foam material with a thin metallic ring structure, achieving effective containment with reduced overall weight compared to traditional all-metal containment rings. The foam provides the bulk of the energy absorption function, allowing the metallic structure to be minimized to only what is necessary for structural integrity.

Inventive Principle:
Principle #40Composite materials

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 design effectively contains blade debris while minimizing peak containment forces, reducing the need for large keep-out zones and nacelle loft, and enabling a lighter, more efficient engine structure.

Implementation Method 1

the cavity of the at least one axial hairpin feature is filled with a lightweight bulk material and the lightweight bulk material is one of a potting material, foam or honeycomb

Methodology Applied
Scientific EffectKinetic energy absorption: Deformation

Implementation Method 2

which absorb kinetic energy and redistribute containment forces, reducing peak stresses

Methodology Applied
Scientific EffectEnergy dissipation: Damping

Data Source

PatentEP4644667A1Containment ring for gas turbine engine
Publication Date: 2025.11.05 PRATT & WHITNEY CANADA CORP
  • EP4644667A1 patent drawingFigure 1
  • EP4644667A1 patent drawingFigure 2
  • EP4644667A1 patent drawingFigure 3

AI summary

A casing (72) for a gas turbine engine (10), including: at least one axial hairpin feature (74) located proximate to either a forward flange (76) or a rearward flange (76) of the casing (72); and a central connecting portion (92) extending from the at least one axial hairpin feature (74), the at least one axial hairpin feature (74) being located between the central connecting portion (92) and one of the forward flange (76) or a rearward flange (76), the central connecting portion (92) including a plurality of features (94) that extend from the at least one axial hairpin features (74), each feature (94) of the plurality of features (94) has a pair of radially extending portions (93), each pair of radially extending portions (93) are connected to each other by an upper portion (95) and one of each pair of the radially extending portions (93) of one of the plurality of features (94) is connected to another one of a pair of radially extending portions (93) of an adjacent feature (94) of one of the plurality of features (94) by a lower portion (97), wherein the upper portion (95) is radially outward with respect to the lower portion (97) such that a plurality of troughs (101) and peaks (103) are defined by the plurality of features (94).