Variable-Area Turboprop Ejector Nozzle for Multi-Segment Efficiency
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Solution Overview
Problem
Turboprop engines with fixed exhaust areas are suboptimal for performance across different flight segments, such as cruise and takeoff, due to inefficient exhaust area sizing.
Innovation Solution
A turboprop engine with a variable area nozzle ejector system featuring movable panels in the secondary exhaust nozzle, actuated hydraulically or by motors, allowing adjustment of exhaust area to optimize performance across flight stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed exhaust area is used in the secondary exhaust nozzle, then the structure is simple and easy to manufacture, but the engine performance is suboptimal for different flight segments
Solution Approach 1:
The patent applies the dynamics principle by replacing the fixed exhaust nozzle structure with a variable area nozzle that can dynamically adjust its cross-sectional area. The secondary exhaust nozzle incorporates movable panels (150, 170) that can pivot to change the exhaust area, allowing the engine to optimize performance across different flight segments such as takeoff, cruise, and descent. This dynamic adjustment capability directly resolves the contradiction by enabling adaptability while accepting increased structural complexity.
Solution Approach 2:
The patent applies segmentation by dividing the secondary exhaust nozzle into multiple movable panels (150, 170) that can independently pivot. This segmentation allows for granular control of the exhaust area, enabling precise optimization for different flight conditions. The nozzle is divided into controllable segments rather than a single fixed structure, resolving the contradiction between adaptability and complexity through modular adjustability.
2Productivity
If the exhaust area is sized for optimum performance in one flight segment, then performance is optimized for that segment, but performance is suboptimal for other flight segments
Solution Approach 1:
The variable area nozzle enables dynamic optimization of engine efficiency across different flight segments. During takeoff, the nozzle maintains a larger exhaust area for maximum power output, while during cruise, it adjusts to an optimal area for fuel efficiency. This dynamic adjustment resolves the contradiction by allowing the system to achieve optimal productivity for each specific flight condition rather than compromising for a fixed design point.
Solution Approach 2:
The patent applies parameter changes by varying the exhaust area parameter in response to different flight conditions. The movable panels are actuated to change the geometric parameters of the exhaust nozzle, allowing the system to optimize engine efficiency for each flight segment. This parameter adjustment capability resolves the contradiction between maintaining high productivity and achieving adaptability across diverse operating conditions.
3Adaptability or versatility
If movable panels are added to the secondary exhaust nozzle, then exhaust area can be adjusted for optimal performance, but device complexity increases
Solution Approach 1:
The complex function of variable area control is achieved through segmentation into discrete movable panels (150, 170) with pivot connections. Each panel can be independently actuated, breaking down the complex control function into manageable segments. This segmentation approach resolves the contradiction by implementing adaptability through modular components rather than a monolithic complex structure.
Solution Approach 2:
The patent introduces dynamic elements (movable panels with pivot connections) into the otherwise static nozzle structure. This dynamic capability enables exhaust area adjustment while maintaining a relatively simple overall nozzle geometry. The dynamic components are integrated into the existing nozzle framework, resolving the contradiction between adding adaptability and minimizing structural complexity.
Data Source
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AI summary
An exhaust assembly for a turboprop engine (20), the assembly having: a primary exhaust nozzle disposed at an aft end of an engine core of the turboprop engine; a secondary exhaust nozzle (46) extending aft from the primary exhaust nozzle (44) to an aft end (46B) of the secondary exhaust nozzle (46), a movable panel (150) disposed in the aft end (46B) of the secondary exhaust nozzle (46) and movable to decrease an area of the secondary exhaust nozzle (46).