Variable-Geometry Exhaust Seal with Spring-Loaded Translation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft exhaust systems face challenges in sealing gaps with variable geometrical configurations, as existing seals struggle to maintain durability and wear resistance while accommodating changes in gap size due to flap movement, temperature, and pressure fluctuations, leading to exhaust leakage that affects aerodynamic performance.
Innovation Solution
An apparatus comprising a housing, a seal, and an energy storing device is used, where the seal is positioned to contact a surface and extends into the housing, allowing it to translate in response to changes in gap size, using mechanisms like springs, pressurized air compartments, or lever systems to maintain contact and reduce exhaust flow through the gap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a seal is used to reduce exhaust leakage through gaps, then aerodynamic performance is improved, but the seal experiences increased wear and reduced durability due to variable gap sizes
Solution Approach 1:
The seal is made movable relative to the housing through an energy storing device (spring), allowing it to dynamically adjust its position as the gap size changes during flight operations. This dynamic adjustment maintains continuous contact between the seal and the fixed structure, ensuring effective sealing while accommodating variable gap geometries without excessive wear
Solution Approach 2:
The energy storing device changes the operational parameters of the seal by storing and releasing mechanical energy. The spring compresses and extends in response to gap size variations, maintaining optimal sealing pressure and contact force across different operating conditions, thereby improving both sealing effectiveness and seal durability
2Ease of operation
If the gap size is allowed to vary to accommodate flap movement and thermal expansion, then ease of operation is improved, but exhaust leakage increases affecting aerodynamic performance
Solution Approach 1:
The seal acts as an intermediary element between the movable flap and the fixed structure. It fills the gap created by relative movement while allowing the flap to move freely, thus maintaining aerodynamic performance without restricting ease of operation. The energy storing device ensures the seal maintains contact throughout the range of motion
3Object-affected harmful factors
If a rigid seal is used to maintain contact with the surface, then sealing effectiveness is improved, but the seal cannot accommodate changes in gap size due to thermal expansion and pressure fluctuations
Solution Approach 1:
The seal system transitions from a rigid, fixed-position design to a dynamic, movable design. The energy storing device enables the seal to adapt its position and contact pressure in real-time as gap dimensions change due to thermal expansion, pressure fluctuations, or mechanical movement, maintaining sealing effectiveness across varying conditions
Solution Approach 2:
The energy storing device (spring) automatically adjusts the seal position in response to changing gap conditions without external control. The spring compresses when the gap narrows and extends when the gap widens, providing self-regulating adaptation to thermal and pressure variations
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 effectively reduces exhaust leakage through variable geometry gaps, maintaining aerodynamic performance by ensuring continuous seal contact and durability, even as gaps widen or narrow, thereby preventing excessive temperature fluctuations and improving overall system efficiency.
Implementation Method 1
The energy storing device is coupled to the housing and engaged with the seal such that the energy storing device allows the seal to translate in a first direction relative to the housing when the gap increases and in a second direction opposite the first direction relative to the housing when the gap decreases
Data Source
AI summary
An apparatus comprising a housing, seal, and energy storing device. The housing is coupled to a structure in an exhaust system of an aircraft. The structure is positioned relative to a surface within the exhaust system such that a gap is present between the surface and structure. The seal has an end positioned in contact with the surface to reduce a flow of exhaust through the gap and is coupled to the housing such that the seal extends within the housing. The energy storing device is coupled to the housing and engaged with the seal to allow the seal to translate in a first direction relative to the housing when the gap increases and in a second direction opposite the first direction relative to the housing when the gap decreases such that the seal continues to reduce the flow of exhaust through the gap as the gap changes in size.