Wind Tunnel Sting Damper Using Viscoelastic Shear Damping
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Solution Overview
Problem
Conventional wind tunnel testing techniques face challenges in mitigating vibrations induced by dynamic loading, which limits the operation envelope and compromises data quality due to increased model distortion and reduced balance sensitivity.
Innovation Solution
A wind tunnel sting damper system comprising a reactive member and a viscoelastic member, where the reactive member is sized to radially compress the viscoelastic member against the support member, generating shear forces that counter relative movement and effectively dampen vibrations in multiple axes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the stiffness of the wind tunnel model support system is increased to reduce vibrations, then vibration mitigation is improved, but model distortion increases and balance sensitivity decreases
Solution Approach 1:
The support system is segmented into multiple functional components: a rigid support structure for stability, a balance system for measurement, and a tuned mass damper for vibration control. This segmentation allows each component to perform its specific function without compromising the others, resolving the contradiction between vibration mitigation and measurement precision.
Solution Approach 2:
A tuned mass damper is introduced as an intermediary element between the rigid support structure and the wind tunnel model. This damper absorbs and dissipates vibrational energy, acting as a mediator that reduces vibrations transmitted to the model while maintaining the rigidity of the support structure, thereby preventing model distortion.
2Stability of the object's composition
If the diameter of the wind tunnel sting is increased to reduce vibrations, then vibration mitigation is improved, but balance sensitivity decreases
Solution Approach 1:
The sting structure is segmented into a main rigid sting for structural stability and a separate tuned mass damper system for vibration control. This allows the sting to maintain its original diameter for balance sensitivity while the damper handles vibration mitigation independently.
Solution Approach 2:
Instead of changing the sting diameter, the solution changes the dynamic parameters of the support system by adding a tuned mass damper with specific mass and damping characteristics. This alters the system's vibrational response without affecting the geometric parameters that determine balance sensitivity.
3Stability of the object's composition
If wind tunnel dynamic pressure is reduced to mitigate vibrations, then vibration mitigation is improved, but scale effects increase
Solution Approach 1:
A tuned mass damper is introduced as an intermediary vibration control mechanism that operates independently of the aerodynamic loading conditions. This allows full dynamic pressure to be maintained for accurate scale effects while the damper actively mitigates vibrations through its mass-spring-damper mechanism.
Solution Approach 2:
The passive vibration mitigation approach of reducing dynamic pressure is replaced with an active mechanical vibration control system (tuned mass damper). This substitution allows the aerodynamic conditions to remain unchanged for data accuracy while vibrations are controlled through mechanical means.
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 provides effective vibrational damping of wind tunnel stings, allowing for data acquisition in areas with unsteady aerodynamics while maintaining structural integrity and low operational costs, without the need for additional damping structures or complex systems.
Implementation Method 1
a viscoelastic member disposed between the reactive member and the support member wherein, the reactive member is sized relative to the support member so as to radially compress the viscoelastic member against the support member
Implementation Method 2
generating shear forces at an interface between the viscoelastic member and the wind tunnel sting and at the interface between the viscoelastic member and the reactive member, where the shear forces counter relative movement
Data Source
AI summary
A wind tunnel sting comprising a support member and a wind tunnel sting damper. The support member having a first support-member end configured for coupling with a wind tunnel, and a second support-member end configured for coupling with a balance. The wind tunnel sting damper having a reactive member, and a viscoelastic member disposed between the reactive member and the support member wherein, the reactive member is sized relative to the support member so as to radially compress the viscoelastic member against the support member.