Aircraft Propulsion System Using Flapping Wing Ducts
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Solution Overview
Problem
Current VTOL aircraft face challenges with noise, safety, efficiency, and cost due to the use of rotating wings, which are inefficient and pose risks, especially in populated areas, and smaller multicopters lack the capacity for long-distance load transport and safety.
Innovation Solution
A propulsion system utilizing ducts with flapping or waving wing members, where the wing motion creates thrust within the duct, reducing exposure of moving parts, enhancing efficiency, and allowing for safer descent and reduced noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If rotating wings (propellers, rotors) are used to achieve vertical take-off, then thrust generation efficiency is improved, but noise levels increase and safety concerns arise due to exposed high-speed rotating blades
Solution Approach 1:
A duct is introduced as an intermediary component between the flapping wing and the external environment. The duct contains the flapping wing mechanism, allowing thrust generation while shielding the moving parts from direct exposure, thereby reducing noise propagation and safety hazards to people and animals on the ground.
Solution Approach 2:
The rotating wing mechanism is extracted and replaced with a flapping wing mechanism that operates within a duct. This extraction allows the system to achieve vertical thrust through a different mechanical principle (flapping motion rather than rotation) while containing the mechanism to reduce its harmful external effects.
2Object-affected harmful factors
If ducted fans are used to reduce noise, then noise levels decrease, but weight and cost increase due to three-dimensional duct shape and engineering requirements
Solution Approach 1:
The duct geometry is changed from a conventional three-dimensional curved shape to a simplified planar or near-planar structure with straight or slightly curved panels. This parameter change in the duct's geometric complexity significantly reduces manufacturing cost and structural weight while maintaining the noise reduction function.
Solution Approach 2:
The duct is segmented into multiple flat or slightly curved panels that can be independently manufactured and assembled. This segmentation simplifies the manufacturing process, reduces material requirements, and lowers both weight and cost compared to a monolithic three-dimensional duct structure.
3Area of stationary object
If smaller diameter propellers are used, then aircraft footprint is reduced, but efficiency decreases due to vortex ring state and inability to autorotate for safe descent
Solution Approach 1:
The flapping wing mechanism within the duct is designed to automatically autorotate during descent by exploiting the relative wind generated by downward motion. This self-service capability allows the system to maintain thrust efficiency during autorotation without requiring external assistance, enabling safe descent while maintaining a compact footprint.
4Reliability
If multiple small diameter propellers are used for distributed propulsion, then system redundancy is improved, but noise levels remain too great for regular operation in populated areas
Solution Approach 1:
The duct serves as an intermediary that contains and shields multiple flapping wing mechanisms, allowing the system to maintain high redundancy with multiple independent thrust-producing units while the duct structure collectively reduces the noise output of all units combined, enabling operation in populated areas.
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 system achieves reduced noise and increased safety while maintaining efficiency and weight, enabling effective vertical take-off and landing, as well as cruise flight capabilities with improved control and reduced mechanical complexity.
Implementation Method 1
the flapping or waving motion of the at least one wing member creates alternating high pressure, decreasing cavities and low pressure, expanding cavities between at least part of the flapping wing member and the duct means walls
Implementation Method 2
a thrust producing vortex stream is created, downstream of the flapping or waving wing member, by the flapping action of the same
Data Source
AI summary
The present invention provides a propulsion system for an aircraft. The system includes one or more thrust producing portions, wherein the one or more thrust producing portions include one or more duct means. The duct means are at least partially formed or defined by two or more substantially parallel wall members. At least one flapping or waving wing member is provided, at least partially located or positioned substantially within the one or more duct means, wherein the flapping or waving motion of the at least one wing member creates thrust, enabling the aircraft to fly in use.