Split Blended Winglet Bending Moment Reduction
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Solution Overview
Problem
Existing winglet designs reduce drag but increase the bending moment on the wing, leading to inefficiencies in fuel burn and cruise performance.
Innovation Solution
A split winglet design featuring separate upward and downward extensions, with a ventral fin that counters vortices, reducing drag without increasing bending moment, and improving cruise performance by integrating an additional surface below the wing chord plane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a traditional winglet is added to reduce drag, then drag reduction is achieved, but the bending moment on the wing increases
Solution Approach 1:
The winglet is divided into two separate elements: an upper winglet extending above the wing chord plane and a lower ventral fin extending below the wing chord plane. This segmentation allows the upper winglet to reduce drag while the lower ventral fin counteracts the bending moment, resolving the contradiction between drag reduction and bending moment increase.
Solution Approach 2:
The lower ventral fin acts as a counterweight element that generates aerodynamic forces to offset the bending moment created by the upper winglet. By positioning mass and aerodynamic surfaces below the wing chord plane, the design creates a counterbalancing effect that reduces the net bending moment on the wing while maintaining drag reduction benefits.
2Loss of energy
If an existing blended-winglet configuration is used, then drag reduction is achieved, but cruise performance improvement is limited
Solution Approach 1:
The invention extends the traditional two-dimensional winglet concept into the third dimension by adding a lower element below the wing chord plane. This dimensional expansion creates additional aerodynamic surfaces that interact with the airflow to reduce drag more effectively and improve cruise performance beyond what conventional single-sided blended winglets can achieve.
Solution Approach 2:
The split winglet configuration combines two distinct aerodynamic elements (upper winglet and lower ventral fin) into a composite structure that works synergistically. The interaction between these two elements creates a combined aerodynamic effect that exceeds the sum of individual contributions, achieving superior drag reduction and cruise performance improvement.
3Object-generated harmful factors
If a ventral fin is added below the wing chord plane, then vortices from wingtip interactions are countered, but device complexity increases
Solution Approach 1:
The upper winglet and lower ventral fin are merged into a single integrated split winglet assembly that attaches to the wing tip as one unit. This merging approach consolidates multiple aerodynamic functions into a single structure, reducing the complexity of installation and structural integration while maintaining the vortex-countering benefits of the ventral fin.
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 split winglet design achieves 1.5% to 9.5% drag reduction and over 40% improvement in cruise performance compared to unmodified wings, with minimal structural changes, enhancing fuel efficiency and reducing noise while maintaining controllability.
Implementation Method 1
The ventral fin counters vortices generated by interactions between the wingtip and the lower wing surface
Implementation Method 2
The upward sloping element similar to an existing winglet and a down-ward canted element (ventral fin)
Implementation Method 3
Winglets reduce drag generated by wingtip vortices
Data Source
Figure 1A~1C
Figure 2
Figure 3A~3B
AI summary
A split winglet is disclosed having a first generally upward projecting wing end, and a second generally downward projecting wing end. The second generally downward projecting wing end may be integrally formed with the first generally upward projecting wing end to form a winglet assembly or may be separately attached onto an existing upwardly curved winglet.