Thrust Reverser Door Frame Design for Reduced Side Spillage

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Solution Overview

Problem

The effective width of thrust reverser doors in turbofan gas turbine engines is limited by large longitudinal side frame members, leading to reduced efficiency and increased reverse efflux side spillage, which decreases the containment and efficiency of the thrust reverser.

Innovation Solution

The design incorporates two longitudinal frame walls on each side of the thrust reverser door, which are strategically positioned to provide structural support while minimizing side spillage by redirecting lateral airflow into channels that enhance containment and redirect it forward, thereby improving the thrust reversing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If large longitudinal side frame members are provided for structural and aerodynamic reasons, then structural strength and aerodynamic stability are improved, but the effective width of the thrust reverser doors is reduced and reverse efflux side spillage increases

Engineering Contradiction:
Improvestructural strengthVSAvoidthrust reverser efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The door is divided into multiple sections with longitudinal frame members positioned at specific intervals. These frame members segment the door structure to provide necessary structural support while minimizing their impact on the effective width, allowing the door to maintain both strength and thrust reverser efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The longitudinal frame members are strategically positioned and dimensioned to provide localized structural support only where needed, rather than using continuous large frame members across the entire door width. This allows the door to have sufficient strength at critical locations while maintaining maximum effective width in other areas.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If large longitudinal side frame members are provided, then structural stability is improved, but reverse efflux containment is reduced

Engineering Contradiction:
Improveaerodynamic stabilityVSAvoidreverse efflux side spillage
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The harmful effect of frame members on efflux containment is addressed by extracting or removing portions of the frame members that would interfere with efflux containment, or by positioning them in locations where they minimize interference with the reverse thrust flow pattern.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Airsteps or flow control features are introduced as intermediary elements between the longitudinal frame members and the efflux flow. These intermediaries help guide the efflux flow around the frame members, reducing side spillage while maintaining the structural stability provided by the frame members.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Area of stationary object

If the geometrical width of doors is increased to match nacelle cross section, then structural support is improved, but the effective width is reduced due to frame members

Engineering Contradiction:
Improvedoor geometrical widthVSAvoidthrust reverser efficiency
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The door design employs asymmetric positioning and dimensioning of frame members, with different frame member configurations on different sections of the door. This allows the door to achieve maximum geometrical width to match the nacelle cross section while the asymmetric frame placement minimizes the reduction in effective width, optimizing both structural support and thrust reverser efficiency.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2060766B1Thrust reverser and method of redirecting jet engine thrust
Publication Date: 2019.07.17 PRATT & WHITNEY CANADA CORP
  • EP2060766B1 patent drawingFigure 1
  • EP2060766B1 patent drawingFigure 2~3
  • EP2060766B1 patent drawingFigure 4

AI summary

A thrust reverser door (24) is provided, in one configuration, with a plurality of peripherally-disposed frames (40, 42) circumferentially spaced apart from one another and projecting radially inwardly on an interior side of the door to thereby provide a channel (60, 62) for redirecting thrust.