Fairing Mount Link Pivot Axis Thermal Expansion

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Solution Overview

Problem

The existing fairing systems in gas turbine engines face challenges in efficiently directing airflow between high-pressure and low-pressure turbines while managing thermal expansion and weight reduction, particularly due to the use of ceramic matrix composites which expand differently than other materials used in the engine components.

Innovation Solution

A fairing assembly with an inner and outer fairing platform, vanes, a mount, and a link with a pivot axis configuration that allows for radial movement due to thermal expansion, using ceramic matrix composites to reduce weight and enhance thermal capabilities, while maintaining structural integrity through a mount and link assembly that connects to the outer casing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If ceramic matrix composites are used in the fairing, then weight is reduced and thermal capabilities are enhanced, but thermal expansion differences cause misalignment with other engine components

Engineering Contradiction:

Improvefairing weightVSAvoiddimensional stability

Core Design Contradiction:

Weight of moving objectVSStability of the object's composition

Solution Approach 1:

The patent changes the physical state and properties of the fairing by using ceramic matrix composites instead of traditional metals, accepting different thermal expansion characteristics while managing the consequences through design

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The mount and link assembly act as an intermediary between the fairing and outer casing, absorbing the thermal expansion differences and preventing direct stress transmission that would cause misalignment

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If a rigid connection is used to secure the fairing to structural components, then structural integrity is maintained, but thermal expansion causes stress and potential failure

Engineering Contradiction:

Improvestructural integrityVSAvoidconnection reliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The connection system transitions from a rigid fixed connection to a dynamic articulated connection using a mount and link with pivot axis, allowing movement while maintaining structural integrity

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent explicitly addresses thermal expansion by designing the mount and link assembly to accommodate the expansion and contraction of the fairing relative to the outer casing, preventing stress buildup

Inventive Principle:

Principle #37Thermal expansion

3Productivity

If the fairing is tightly secured to maintain precise airflow direction, then airflow efficiency is improved, but weight increases and thermal management becomes difficult

Engineering Contradiction:

Improveairflow efficiencyVSAvoidfairing assembly weight

Core Design Contradiction:

ProductivityVSWeight of moving object

Solution Approach 1:

The fairing uses a lightweight structure with platforms and vanes that can be made from thin ceramic matrix composite materials, achieving the required airflow guidance without heavy reinforcement

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent employs ceramic matrix composites for the fairing components, providing both the structural integrity needed for precise airflow direction and the weight reduction benefits, while the mount and link assembly manages the thermal consequences

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 solution effectively guides airflow, reduces weight, and accommodates thermal expansion, enhancing the operational efficiency and longevity of the fairing system by using ceramic matrix composites and a pivot axis configuration that manages thermal expansion and axial loads.

Implementation Method 1

a link with a pivot axis configuration that allows for radial movement due to thermal expansion

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10202869B2Connection for a fairing in a mid-turbine frame of a gas turbine engine

Publication Date: 2019.02.12 RTX CORP

AI summary

A fairing assembly for a gas turbine engine includes an inner fairing platform; an outer fairing platform located radially outward of the inner fairing platform; a plurality of vanes radially outward from the inner fairing platform between the inner fairing platform and outer fairing platform; a mount located on a radially outer side of the outer fairing platform, the mount attached to the outer fairing platform on the radially outer side; and a link that includes an elongated member with a first end and an opposite second end, the first end configured to fit within the mount and define a pivot axis of the link with respect to the mount.