Exhaust Nozzle Sealing Module for Articulating Flap Leakage
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Solution Overview
Problem
The escape of core and/or bypass air around the exhaust nozzle of a gas turbine engine leads to leaks into the engine bay, affecting temperature-sensitive components and causing thrust losses.
Innovation Solution
A propulsion machine with a sealing module that includes a moveable member and an extendable structure, actuated by pressurized fluid, to provide a seal between the moveable member and a wall, using a mounting structure and extendable structure with interface surfaces to maintain a seal during movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If articulating flaps are used to control exhaust nozzle area, then thrust control and exhaust flow management are improved, but air leakage around the flaps increases causing thrust losses and engine bay contamination
Solution Approach 1:
A sealing module is introduced as an intermediary element between the articulating flap and the exhaust nozzle wall. The module includes a seal member that contacts the wall surface to prevent air leakage, while allowing the flap to articulate. This mediator resolves the contradiction by enabling both thrust control through flap articulation and preventing thrust losses through effective sealing.
Solution Approach 2:
The seal member is configured as a flexible element that can deform to accommodate the movement of the articulating flap while maintaining continuous contact with the exhaust nozzle wall. This flexibility allows the sealing surface to adapt to different flap positions, preventing air leakage throughout the range of motion without restricting the flap's articulation capability.
2Loss of energy
If sealing structures are added to prevent air leakage, then thrust losses are reduced, but device complexity increases
Solution Approach 1:
The sealing module combines multiple functions into a single integrated structure: the seal member prevents air leakage, the mounting structure attaches to the articulating flap, and the resilient member provides biasing force. By merging these functions into one compact module rather than separate components, the design reduces overall complexity while achieving effective sealing.
Solution Approach 2:
The resilient member automatically biases the seal member against the exhaust nozzle wall, providing self-adjusting sealing pressure as the flap articulates. This self-service mechanism eliminates the need for external actuation systems or complex control mechanisms to maintain sealing contact, reducing device complexity while ensuring consistent sealing performance throughout the flap's range of motion.
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
Reduces air leaks, protects temperature-sensitive components, and minimizes thrust losses by effectively sealing the exhaust nozzle flaps against the wall, while providing efficient cooling and increased robustness through ceramic materials and resilient biasing.
Implementation Method 1
the sealing module is configured to receive a pressurized actuation fluid into the chamber to actuate movement of the extendable structure and load the sealing surface against an opposing surface of the wall
Implementation Method 2
the extendable structure is resiliently biased away from the mounting structure
Data Source
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AI summary
There is provided a propulsion machine 10 comprising a fluid duct defined by a wall 42, 44 and a moveable member 34, 36 with a sealing module 90, 90' therebetween. The moveable member 34, 36 is moveable relative to the wall 42, 44. The sealing module 90, 90' comprises a mounting structure 92 coupled to the moveable member 34, 36 and an extendable structure 94 having a sealing surface 96. A chamber 98 is defined between the mounting structure 92 and the extendable structure 94 throughout a travel of the extendable structure 94 relative to the mounting structure 92. The sealing module 90, 90' is configured to receive a pressurized actuation fluid into the chamber 98 to load the sealing surface 96 against an opposing surface 43 of the wall 42, 44 to provide a seal with the opposing surface 43.