Coanda Thrust Director for Gas Turbine Exhaust Nozzle

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Solution Overview

Problem

Existing gas turbine engines face challenges in redirecting thrust away from the central axis, which is desirable in certain operational situations, such as during landing or take-off, and also in reducing the infrared signature and potential damage to surfaces.

Innovation Solution

The implementation of a thrust director system comprising an arcuate momentum nozzle and an arcuate coanda nozzle, coupled with a round, annular manifold, which redirects discharge air by applying flow near the exhaust nozzle, allowing the air to exit perpendicular to the central axis, thereby redirecting thrust and utilizing the Coanda effect to influence airflow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If thrust is discharged along the central axis, then engine efficiency is maintained, but the ability to redirect thrust away from the central axis is lost

Engineering Contradiction:
Improvethrust redirection capabilityVSAvoidexhaust nozzle structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The exhaust system is segmented into multiple independent nozzle components (primary exhaust nozzle and secondary deflection nozzles) that can operate independently or in combination, enabling thrust redirection without redesigning the entire exhaust system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The secondary deflection nozzles are designed to be movable or adjustable, allowing the exhaust system to dynamically redirect thrust away from the central axis when needed while maintaining a simple fixed structure for normal operation

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If high velocity air is discharged tangential to create low pressure areas for deflection, then thrust vectoring is achieved, but device complexity increases

Engineering Contradiction:
Improvethrust vectoring capabilityVSAvoidcoanda nozzle structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The coanda effect mechanism is merged with the existing exhaust nozzle structure, where the secondary deflection nozzles utilize the Coanda surface of the primary nozzle to achieve thrust vectoring without requiring completely separate deflection mechanisms

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system uses pneumatic principles by discharging high velocity air tangentially to create low pressure areas that deflect the exhaust gas stream, utilizing fluid dynamics rather than mechanical moving parts to achieve thrust vectoring

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 solution effectively redirects thrust away from the central axis, providing enhanced control during landing or take-off, reducing infrared signature, and minimizing surface damage, while maintaining engine efficiency and robustness.

Implementation Method 1

an arcuate coanda nozzle configured to discharge flow generally parallel to and along the central axis where the coanda surface influences the discharge air to turn and exit the nozzle perpendicular to the central axis

Methodology Applied
Scientific EffectCoanda effect: Coanda Effect

Data Source

PatentEP3135891B1Coanda device for a round exhaust nozzle
Publication Date: 2021.12.08 ROLLS ROYCE NORTH AMERICAN TECHNOLOGIES INC
  • EP3135891B1 patent drawingFigure 1~3
  • EP3135891B1 patent drawingFigure 4~6
  • EP3135891B1 patent drawingFigure 7

AI summary

A gas turbine engine system (12) is disclosed herein. The gas turbine engine system includes an engine core (20) configured to discharge air through an exhaust nozzle (24) along a central axis (16) and a thrust director (22) arranged near the exhaust nozzle and configured to redirect the discharge air by applying flow to the discharge air near the exhaust nozzle.