Interfitting Flap Exhaust Nozzle for Gap Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable exhaust nozzle assemblies for gas turbine engines fail to effectively minimize and control gaps between adjacent flap assemblies during movement, leading to inefficiencies in gas flow and thrust optimization.
Innovation Solution
The design incorporates interfitting flap assemblies with a wing portion and slot portion, featuring a seal with a tented portion and notch to minimize gaps, and a divergent element with a serrated trailing edge, ensuring a continuous and uniform outer surface by preventing leakage and reducing friction between flap assemblies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a simple seal is provided on the hot side of the flaps, then the structure is simple, but the seal cannot block or control all gaps created between adjacent flap assemblies during movement
Solution Approach 1:
The seal is divided into multiple functional portions: a first portion on the hot side, a second portion on the cold side, and an intermediate portion connecting them. Each portion addresses specific gap formation issues at different locations, allowing comprehensive gap control through segmented design rather than a single complex seal structure.
Solution Approach 2:
The seal extends in multiple spatial dimensions with portions positioned at different locations (hot side, cold side, intermediate) and oriented in different directions. This multi-dimensional arrangement allows the seal to control gaps from various angles and positions simultaneously, improving gap control without requiring a single complex three-dimensional structure.
2Adaptability or versatility
If the exhaust nozzle uses a variable opening with multiple flap sections, then performance can be optimized for many operating conditions, but gaps are created between adjacent flaps during movement
Solution Approach 1:
The seal is pre-configured with specific geometric features (first portion, second portion, intermediate portion) that proactively prevent gap formation before the flaps move into positions where gaps would occur. The seal's structure is designed in advance to accommodate the full range of motion and maintain sealing contact throughout the variable opening cycle.
Solution Approach 2:
The intermediate portion of the seal acts as a mediator between the first portion (on the hot side) and the second portion (on the cold side), ensuring continuous sealing contact across the entire flap assembly interface. This intermediate section maintains pressure distribution and sealing effectiveness during the transition between different opening positions.
Data Source
AI summary
An exhaust nozzle assembly includes a plurality of interfitting flap assemblies that are moveable between a maximum area ratio and a minimum area ratio. Each of the pluralities of flap assemblies includes a slot and a wing. The wing fits within an adjacent slot of an adjacent flap assembly. Each of the flap assemblies includes a divergent element that provides a specific geometric shape forming the trailing edge surfaces. The flap element is attached to the divergent element and extends to a static structure. The flap element and the divergent element combine to form a continuous faceted outer surface of the exhaust nozzle assembly substantially void of gaps throughout the range of motion between the maximum and minimum area ratios.