Horizontal Stabilizer Dampers for Multi-Axis Vibration Mitigation

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Solution Overview

Problem

Aircraft horizontal stabilizers experience increased vibrational forces due to turbulent airflow from high bypass ducted fan engines, leading to structural fatigue and passenger discomfort, which existing technologies have not adequately addressed.

Innovation Solution

A vibration dampening system comprising passive and active dampers strategically positioned on the horizontal stabilizer to mitigate vibrational forces in multiple degrees of freedom, using visco-elastic dampers and linear actuators to absorb and counteract vibrations based on real-time or estimated vibration states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If high bypass ducted fan engines are used to improve fuel efficiency, then fuel efficiency is improved, but vibrational forces on the horizontal stabilizer increase causing structural fatigue and passenger discomfort

Engineering Contradiction:
Improvefuel efficiencyVSAvoidvibrational forces
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

A vibration dampening system is introduced as an intermediary component between the horizontal stabilizer and the aircraft structure. The system includes vibration sensors that detect vibrational forces, processors that analyze the sensor data to determine vibration characteristics, and vibration dampeners that actively counteract the detected vibrations. This intermediary system allows the high bypass ducted fan engine to operate for improved fuel efficiency while the dampening system protects the horizontal stabilizer and aircraft structure from excessive vibrational forces.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The vibration dampening system implements a feedback mechanism where vibration sensors continuously monitor the horizontal stabilizer for vibrational forces, the processors analyze the sensor data to characterize the vibrations (frequency, amplitude, direction), and the vibration dampeners apply counteracting forces based on this analysis. This closed-loop feedback system enables real-time adaptation to varying vibration conditions caused by different flight regimes and engine operations, effectively mitigating structural fatigue and passenger discomfort while maintaining the fuel efficiency benefits of high bypass ducted fan engines.

Inventive Principle:
Principle #23Feedback

2Use of energy by moving object

If the size of high bypass ducted fan engines is increased to improve fuel efficiency, then fuel efficiency is improved, but the quantity of jet-wash and resulting vibrational forces increase

Engineering Contradiction:
Improvefuel efficiencyVSAvoidvibrational forces
Core Design Contradiction:
Use of energy by moving objectVSForce

Solution Approach 1:

The vibration dampening system serves as a mediator that decouples the relationship between engine size and structural vibration. By placing vibration sensors on the horizontal stabilizer, processors to analyze vibration characteristics, and dampeners to actively counteract vibrations, the system allows larger high bypass ducted fan engines to be used for improved fuel efficiency without proportionally increasing the harmful vibrational forces transmitted to the aircraft structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If no vibration dampening system is used to maintain structural simplicity, then device complexity is minimized, but structural fatigue increases reducing aircraft lifespan and increasing maintenance costs

Engineering Contradiction:
Improvestructural simplicityVSAvoidstructural fatigue resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces a vibration dampening system as an intermediary solution that addresses structural fatigue without requiring fundamental redesign of the horizontal stabilizer or aircraft structure. The system comprises vibration sensors that detect vibrational forces, processors that analyze the sensor data to determine vibration characteristics (frequency, amplitude, direction), and vibration dampeners that actively counteract the detected vibrations. This modular intermediary system protects the structural integrity and extends aircraft lifespan while maintaining relative simplicity through standardized sensor, processor, and dampener components that can be integrated without complex structural modifications.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Effectively reduces structural fatigue and passenger discomfort by significantly mitigating vibrational forces, enhancing aircraft durability and reducing maintenance costs while maintaining fuel efficiency.

Implementation Method 1

using visco-elastic dampers and linear actuators to absorb and counteract vibrations

Methodology Applied
Scientific EffectVisco-elasticity: Viscoelasticity

Implementation Method 2

using visco-elastic dampers and linear actuators to absorb and counteract vibrations

Methodology Applied
Scientific EffectHysteresis: Hysteresis

Implementation Method 3

using visco-elastic dampers and linear actuators to absorb and counteract vibrations based on real-time or estimated vibration states

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnetic Induction

Data Source

PatentEP3441301B1Vibration dampening for horizontal stabilizers
Publication Date: 2022.01.19 THE BOEING CO
  • EP3441301B1 patent drawingFigure 1
  • EP3441301B1 patent drawingFigure 2
  • EP3441301B1 patent drawingFigure 3

AI summary

Systems and methods provide for the mitigation of vibrational forces acting on a horizontal stabilizer (102) of an aircraft. According to one aspect, a damper (106) is coupled to a front portion of a horizontal stabilizer (102) to dampen vibrations in a first degree of freedom, with another damper (106) coupled to a mounting point (118) of the horizontal stabilizer (102) to dampen vibrations in a second degree of freedom. The dampers (106) may be passive, operating independently to mitigate vibrational forces, or active, applying a mitigating force to the horizontal stabilizer (102) based on real-time or estimated vibration states.