Internal-Actuated Rotor Blade for Low-Noise eVTOL Lift Control
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Solution Overview
Problem
Existing eVTOL aircraft designs face challenges in efficiently carrying a payload of at least 500 pounds using a reduced number of rotors while ensuring safety, efficiency, and maneuverability, particularly during transitions between vertical lift and forward propulsion, due to high disc loading, noise levels, and inefficiencies in current rotor configurations.
Innovation Solution
The design employs a reduced number (2-4) of variable speed, rigid, non-articulated rotors with individual blade control actuators, integrated rotor drive systems, and large wings to optimize lift and propulsion, allowing for safe transitions and efficient flight using current battery technology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a reduced number of rotors (2-4) is used to improve efficiency and reduce noise, then power loading and noise levels are improved, but the ability to carry heavy payloads (at least 500 pounds) while maintaining safety is worsened
Solution Approach 1:
The propulsion system is segmented into multiple independent rotor units (2-4 rotors), where each rotor can be independently controlled and failsafed. This segmentation allows the system to maintain reliability even with fewer total rotors, as each rotor is designed to handle specific load requirements and includes redundant control mechanisms.
Solution Approach 2:
The rotors are designed with variable speed capabilities and adjustable pitch angles, allowing dynamic parameter changes to optimize performance for different flight conditions. This enables a reduced number of rotors to handle heavy payloads by adjusting operational parameters to maximize lift and efficiency.
2Device complexity
If variable speed rigid non-articulated rotors are used to simplify the system, then device complexity is reduced, but control precision and maneuverability during transitions are worsened
Solution Approach 1:
The rigid non-articulated rotors are designed to perform multiple functions: they can collectively tilt for vertical-to-horizontal transitions, individually adjust pitch for maneuvering, and work in coordination with wing aerodynamics. This multi-functionality compensates for the lack of individual blade articulation, maintaining ease of operation while simplifying the overall structure.
Solution Approach 2:
The rotor system incorporates variable speed control and collective pitch adjustment capabilities, allowing dynamic adaptation to different flight phases. During transitions, the rotors can rapidly change speed and pitch angles to maintain control precision without requiring complex individual blade articulation mechanisms.
3Productivity
If large wings are added to improve forward flight efficiency, then aerodynamic efficiency is improved, but device complexity and weight are worsened
Solution Approach 1:
The wing structure is merged with the rotor support framework, where the wings serve dual purposes: providing aerodynamic lift during forward flight and structurally supporting the rotor mounting points. This integration reduces overall device complexity by combining structural and aerodynamic functions into unified components.
Solution Approach 2:
The wings are designed as multi-functional elements that provide aerodynamic lift, structural support for rotors, and contribute to overall aircraft stability. This universality improves forward flight efficiency while minimizing the addition of separate components, thereby controlling device complexity.
4Ease of operation
If individual blade control actuators are implemented to improve control precision, then maneuverability is improved, but device complexity and weight are worsened
Solution Approach 1:
Individual blade control actuators are implemented selectively on critical blades rather than uniformly across all blades. This local quality approach provides sufficient control precision for maneuverability while reducing the overall number of actuators, thereby limiting the increase in device complexity and weight.
Data Source
AI summary
Apparatus, systems, and methods are contemplated for electric powered vertical takeoff and landing (eVTOL) aircraft. Such are craft are engineered to carry safely carry at least 500 pounds (approx. 227 kg) using a few (e.g., 2-4) rotors, generally variable speed rigid (non-articulated) rotors. It is contemplated that one or more rotors generate a significant amount of lift (e.g., 70%) during rotorborne flight (e.g., vertical takeoff, hover, etc), and tilt to provide forward propulsion during wingborne flight. The rotors preferably employ individual blade control, and are battery powered. The vehicle preferably flies in an autopilot or pilotless mode and has a relatively small (e.g., less than 45′ diameter) footprint.