Fan Variable Area Nozzle Adaptive Segment
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Solution Overview
Problem
Conventional gas turbine engines with fixed geometry fan nozzles compromise between take-off and cruise conditions, and existing fan variable area nozzles are heavy due to complex mechanisms, negating fuel efficiency gains.
Innovation Solution
A lightweight fan variable area nozzle with a flexible adaptive segment, comprising multiple flexible skins, a linkage, and an actuator system, allowing independent adjustment of sectors to change the fan exit area and shape for optimal thrust and efficiency across different flight conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional fixed geometry fan nozzles are used, then the engine structure is simple and lightweight, but the engine cannot optimize performance across different flight conditions (take-off, cruise, landing)
Solution Approach 1:
The patent applies dynamics by transforming the static fixed geometry nozzle into a dynamic variable area nozzle. The nozzle incorporates movable panels that can change their position and configuration to vary the exit area, allowing the engine to optimize performance across different flight conditions. The actuator system enables the nozzle to transition between different geometric states dynamically.
Solution Approach 2:
The nozzle is segmented into multiple independent movable panels rather than a single rigid structure. Each panel can be controlled independently by its own actuator, allowing for flexible adjustment of the exit area. This segmentation enables complex area variations while keeping individual panel mechanisms relatively simple.
2Adaptability or versatility
If existing fan variable area nozzles with hinged flaps are used, then the fan exit area can be varied, but the complex mechanisms increase overall engine weight significantly
Solution Approach 1:
The patent extracts the heavy complex hinge mechanisms from the design and replaces them with a more lightweight actuator system. The movable panels are designed to be supported and positioned by simpler actuators rather than heavy hinged flap mechanisms, significantly reducing the overall weight while maintaining the variable area capability.
Solution Approach 2:
The nozzle incorporates flexible panels that can deform and move to change the exit area. These flexible panels replace rigid hinged structures, reducing weight while maintaining structural integrity and aerodynamic function. The flexible nature of the panels allows for smooth area transitions.
3Adaptability or versatility
If hinged flaps are deflected into the annular fan flow path to vary area, then the exit area can be adjusted, but drag increases and thrust efficiency decreases
Solution Approach 1:
The nozzle uses dynamic panel positioning to adjust the exit area in a manner that maintains optimal flow characteristics. The panels move to create smooth flow paths rather than abrupt blockages, minimizing flow separation and turbulence. This dynamic adjustment allows area variation while maintaining thrust efficiency.
Solution Approach 2:
The patent employs asymmetrical panel configurations to optimize the exit area shape for different flight conditions. The panels can be positioned at different angles and locations to create asymmetrical flow patterns that are more efficient than symmetrical blockages, reducing drag and improving thrust efficiency during area reduction.
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
A fan variable area nozzle (FVAN) (42) includes a flexible adaptive segment (48) which defines the fan nozzle exit area (44). The flexible adaptive segment (48) generally includes a multiple of flexible sections (50a, 50b), a linkage (52) and an actuator system (54) to morph the flexible adaptive segment (48) between a converged shape and a diverged shape.