Aircraft Wing Spoiler Arrangement with Choked Flow Gaps
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Solution Overview
Problem
Conventional aircraft spoilers are large and complex, requiring significant actuation mechanisms to control lift reduction and drag increase, while maintaining aerodynamic effectiveness.
Innovation Solution
The introduction of gaps between adjacent spoilers, with widths greater than 1 cm but small enough to choke airflow, generating flow vortices and boundary layer interference, which reduces air flow speed through the gap to less than 10% of true air speed, thereby achieving lift reduction with reduced spoiler size and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If spoilers are made large to maintain aerodynamic effectiveness, then lift reduction capability is improved, but spoiler size and actuation complexity increase
Solution Approach 1:
The wing surface is divided into multiple discrete spoiler segments that can be independently controlled. Each spoiler is a separate panel that can be deployed or retracted independently, allowing distributed control of lift reduction across the wing span without requiring a single large complex actuation system
Solution Approach 2:
The spoilers are designed with pivotal attachment allowing dynamic rotation between deployed and retracted positions. The gap width dynamically adjusts based on spoiler deflection angle, enabling the system to adapt airflow choking effect to different flight conditions and reduce the force required for actuation
2Force
If spoilers are closely spaced with no gap to prevent airflow leakage, then aerodynamic effectiveness is improved, but manufacturing complexity and seal requirements increase
Solution Approach 1:
The complex sealing system is extracted and replaced by deliberately introducing gaps between spoilers. Instead of trying to eliminate airflow between closely spaced spoilers with seals, the design accepts the gaps and uses airflow choking through the gaps to achieve the desired aerodynamic effect, significantly simplifying manufacturing
Solution Approach 2:
The gap width parameter is optimized to be sufficiently small to choke airflow (maintaining aerodynamic effectiveness) but large enough to eliminate seal requirements (simplifying manufacturing). This parameter change transforms the design from requiring precision seals to allowing simple gaps
3Ease of manufacture
If gap width is increased to simplify manufacturing, then ease of manufacture is improved, but aerodynamic effectiveness deteriorates due to increased airflow leakage
Solution Approach 1:
The gap width is set to a specific range that balances manufacturing simplicity with aerodynamic effectiveness. The gap is wide enough to eliminate seals but narrow enough to choke airflow, achieving both goals simultaneously through careful parameter selection
Solution Approach 2:
The potential harmful effect of gaps allowing airflow leakage is converted into a beneficial airflow choking effect. By carefully controlling gap width, the airflow through the gaps creates vortices and boundary layer interference that actually enhances the spoiler's aerodynamic effectiveness
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
This configuration reduces spoiler size and complexity, maintaining aerodynamic effectiveness by creating an incompressible flow area that acts as a physical barrier, reducing wing loading and actuation requirements, while increasing efficiency by minimizing deployed spoiler frontal area.
Implementation Method 1
the width of the gap is sufficiently small to choke the flow of air through the gap such that for at least one flight regime with the adjacent spoilers deployed, the average air flow speed through the gap is less than 10% of the true air speed
Implementation Method 2
the width of the gap is sufficiently small to choke the flow of air through the gap such that for at least one flight regime with the adjacent spoilers deployed, they generate flow vortices and/or boundary layers which interfere with each other
Implementation Method 3
the width of the gap is sufficiently small to choke the flow of air through the gap such that for at least one flight regime with the adjacent spoilers deployed, they generate flow vortices and/or boundary layers which interfere with each other
Data Source
AI summary
An aircraft wing comprising an upper surface; and two or more spoilers pivotally attached to the upper surface, wherein at least two adjacent ones of the spoilers are separated by a gap, and wherein the width of the gap is: greater than 1 cm; and sufficiently small to choke the flow of air through the gap such that for at least one flight regime with the adjacent spoilers deployed, the average air flow speed through the gap is less than 10% of the true air speed. The reduced size of the spoilers reduces the spanwise wing loading and the spoiler hinge moment, while providing a net aerodynamic effect (in terms of destroying lift over the wing) similar to that of a conventional spoiler array with no gaps.