Forward Swept T-Tail Thrust Reverser for Fuselage Engines

Solution Overview

Problem

Conventional gas turbine engine configurations are not compatible with unique aircraft architectures, particularly when engines are mounted within the fuselage, as they lack the necessary thrust reversing devices and nacelle structures, which are designed for under-wing installations.

Innovation Solution

A thrust reversing system is developed with a thrust reverser supported proximate a propulsor system and a vertical stabilizer that extends forwardly, directing discharge flow away from the vertical stabilizer, along with a horizontal stabilizer angled forward, and thrust reversers that pivotally mounted doors to capture bypass and core flow streams, ensuring airflow is directed away from the tail.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If engines are mounted within the fuselage to enable unique aircraft configurations, then aircraft architecture versatility is improved, but compatibility with conventional thrust reversing devices is worsened

Engineering Contradiction:

Improveaircraft architecture versatilityVSAvoidthrust reversing compatibility

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The thrust reverser system is divided into multiple independent door assemblies (upper and lower doors) that can be selectively deployed. Each door assembly independently redirects thrust, allowing the system to adapt to the fuselage-mounted engine configuration while maintaining effective thrust reversal capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The vertical stabilizer is extended forwardly into the exhaust flow path, creating a new spatial dimension for flow redirection. This forward extension allows the stabilizer to interact with the exhaust gases in a way that conventional tail designs cannot, enabling thrust reversal without impacting the tail structure.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Device complexity

If conventional thrust reversers are used with fuselage-mounted engines, then device simplicity is maintained, but harmful effects on the tail structure increase

Engineering Contradiction:

Improvethrust reverser structure simplicityVSAvoidtail impact from discharge flow

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The forward-swept vertical stabilizer acts as an intermediary element between the thrust reverser discharge flow and the horizontal stabilizer. It redirects the exhaust flow away from the horizontal stabilizer, preventing direct impingement while maintaining the simplicity of the thrust reverser system.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The vertical stabilizer is swept forward at an asymmetric angle (greater than 30 degrees from vertical) that specifically directs discharge flow away from the horizontal stabilizer. This asymmetric geometry optimizes flow redirection while maintaining structural simplicity.

Inventive Principle:

Principle #4Asymmetry

3Device complexity

If the vertical stabilizer is positioned conventionally, then structural simplicity is maintained, but discharge flow impacts the tail reducing aircraft stability

Engineering Contradiction:

Improvevertical stabilizer configurationVSAvoidaircraft stability during thrust reversal

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The vertical stabilizer is swept forward at an asymmetric angle (greater than 30 degrees from vertical) that specifically directs discharge flow away from the horizontal stabilizer. This asymmetric geometry optimizes flow redirection while maintaining structural simplicity.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The vertical stabilizer is extended forwardly into the exhaust flow path, creating a new spatial dimension for flow redirection. This forward extension allows the stabilizer to interact with the exhaust gases in a way that conventional tail designs cannot, enabling thrust reversal without impacting the tail structure.

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

This configuration allows for effective thrust reversal during landing without impacting the tail, maintaining aircraft stability and compatibility with alternate engine mounting locations, enabling favorable engine architectures for specific aircraft configurations.

Implementation Method 1

A thrust reverser supported proximate a propulsor system for redirecting thrust

Methodology Applied

Scientific EffectThrust reversal: Reaction (physics)

Implementation Method 2

a vertical stabilizer that is proximate to the propulsor system and extending forwardly away from the thrust reverser, whereby discharge flow from the thrust reverser is configured for being directed away from the vertical stabilizer

Methodology Applied

Scientific EffectFlow direction control: Aerodynamic Heating

Data Source

PatentUS9637218B2Aircraft with forward sweeping T-tail

Publication Date: 2017.05.02 RTX CORP

AI summary

An aircraft includes a propulsor supported within an aft portion of the fuselage. A thrust reverser is supported proximate the propulsor for redirecting thrust forward to slow the aircraft upon landing. A tail extending from the aft portion of the fuselage is angled forward away from the aft portion and out of the discharge of airflow from the thrust reverser.