Variable Area Nozzle Assembly Ejector Sleeve Dynamics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable area nozzle assemblies for gas turbine engines do not effectively accommodate varying flight conditions, particularly in subsonic, transonic, and supersonic speeds, and lack efficient means to introduce ambient air for improved engine efficiency.
Innovation Solution
A variable area nozzle assembly featuring a fixed structure with pivotable ejector doors and a translating ejector sleeve that allows axial translation to open or close the ejector passage, enabling airflow from outside to inside the nozzle, and includes a pivotable A8 door to adjust the throat cross-sectional area, along with thrust reverser doors for optimized performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed nozzle area is used, then the structure is simple, but the engine cannot accommodate varying flight conditions (subsonic, transonic, and supersonic speeds)
Solution Approach 1:
The patent applies dynamics by making the nozzle area variable through movable components. The ejector doors (forward and aft) are configured to pivot between closed and open positions, and the ejector sleeve translates axially, allowing the nozzle passage area to dynamically adjust according to flight conditions (subsonic, transonic, and supersonic speeds), thereby resolving the contradiction between structural simplicity and adaptability.
Solution Approach 2:
The nozzle is segmented into multiple controllable sections: the forward ejector door, aft ejector door, and ejector sleeve. Each segment can be independently positioned to adjust the effective area of the nozzle passage, enabling precise control over exhaust flow characteristics for different flight regimes while maintaining a relatively simple overall structure.
2Productivity
If ambient air is introduced to the nozzle exhaust, then engine efficiency is improved, but the device complexity increases
Solution Approach 1:
The ejector sleeve is designed to translate axially between retracted and extended positions, dynamically controlling the introduction of ambient air into the nozzle exhaust. When extended, the sleeve creates an opening that allows ambient air to be drawn in and mixed with the exhaust, improving engine efficiency. This dynamic control mechanism achieves the desired performance improvement while maintaining reasonable structural complexity through a single translational motion component.
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 enhances engine efficiency by allowing airflow introduction and adjusting nozzle area to suit varying flight conditions, improving thrust and engine performance across different speeds while maintaining a compact configuration.
Implementation Method 1
the ejector passage is open such that the ejector passage is configured to allow air flow therethrough from radially outside the fixed structure to radially inside the nozzle
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A variable area nozzle assembly (50) for a gas turbine engine (20) includes a fixed structure (52) including a first fixed ring (64) and a second fixed ring (66). The second fixed ring (66) is spaced axially aft from the first fixed ring (64) to define a first portion of an ejector passage (68) therebetween. A nozzle (58) defines an inner radial exhaust flow path surface (74). The nozzle (58) includes a forward ejector door (86) and an aft ejector door (88). The forward ejector door (86) and the aft ejector door (88) define a first surface portion of the inner radial exhaust flow path surface (74). Each of the forward ejector door (86) and the aft ejector door (88) are pivotable between respective closed positions and respective open positions. A translating ejector sleeve (108) is mounted within the fixed structure (52) and configured to axially translate within the fixed structure (52) between a first axial position and a second axial position.