Rotorcraft Control Apparatus for High-Speed Flight
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Solution Overview
Problem
Current rotorcraft are limited in maximum flight speed due to phenomena such as retreating blade stall, high drag at rotor tips, and reverse airflow over retreating blades, which restrict their top speed to less than 200 mph and require less precise and more slack-filled control systems.
Innovation Solution
The design incorporates a rotor system with a mast, rotor hub, swashplate, and pitch control arms, along with a mast tilt actuator and vibration suppression components, and uses compressed air to enhance airflow efficiency and reduce pressure losses, allowing for more precise control and higher speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If rotorcraft use conventional control systems with more slack, then the system is simpler and easier to manufacture, but control responsiveness deteriorates and maximum flight speed is limited to less than 200 mph
Solution Approach 1:
The control system employs dynamic elements including a swashplate mechanism that converts reciprocating motion from linear actuators into rotational blade pitch changes. The system dynamically adjusts blade angles during flight to maintain optimal aerodynamic performance across varying speeds, enabling responsive control at high velocities without requiring overly complex rigid linkages
Solution Approach 2:
The patent replaces traditional cable-pulley mechanical control systems with direct-acting linear actuators that provide more precise and responsive blade pitch control. This substitution eliminates slack-filled mechanical linkages while reducing overall system complexity through more direct actuation paths from control inputs to blade pitch changes
2Speed
If rotorcraft achieve higher flight speeds exceeding 200 mph, then productivity and mission capability improve, but retreating blade stall and reverse airflow phenomena worsen
Solution Approach 1:
The rotor blades are designed with dynamic pitch control that automatically adjusts blade angles during high-speed flight. The swashplate mechanism enables cyclic pitch changes that compensate for retreating blade stall by increasing pitch on retreating blades and decreasing pitch on advancing blades, maintaining balanced aerodynamic performance across the rotor disk at speeds exceeding 200 mph
Solution Approach 2:
The system changes aerodynamic parameters by varying blade pitch angles in response to flight conditions. At high speeds, the control system modifies pitch parameters to prevent retreating blade stall and manage reverse airflow effects, allowing the rotorcraft to operate efficiently beyond conventional speed limits through real-time parameter adjustment
3Stability of the object's composition
If rotorcraft use forced rotation with counter rotating rotors or tail rotor to counteract reactive torque, then stability improves, but device complexity and power requirements increase
Solution Approach 1:
The patent extracts and eliminates the need for counter-rotating rotors or tail rotors by using the ground effect and carefully controlled autorotation to naturally counteract reactive torque. The single rotor system relies on aerodynamic interactions with the ground surface and precise control of rotor disc attitude to maintain stability without additional rotating components
Solution Approach 2:
The rotor system performs self-stabilization through autorotation control and ground effect interactions. The rotor blades automatically generate restoring moments that counteract reactive torque without requiring separate stabilization systems, allowing the aircraft to maintain stability through inherent aerodynamic properties and controlled descent
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
Enables vertical takeoff and landing while achieving flight speeds exceeding 200 mph with improved control responsiveness and reduced drag, addressing the limitations of existing rotorcraft.
Implementation Method 1
A swashplate encircles the mast and has a rotating plate and a non-rotating plate. A plurality of pitch control rods couple the pitch control arms to the non-rotating plate.
Implementation Method 2
uses compressed air to enhance airflow efficiency and reduce pressure losses
Implementation Method 3
An autogyro aircraft derives lift from an unpowered, freely rotating rotor or plurality of rotary blades. The energy to rotate the rotor results from a windmill-like effect of air passing through the underside of the rotor.
Implementation Method 4
along with a mast tilt actuator and vibration suppression components
Data Source
AI summary
A rotor system of a reactive drive rotary wing maintains rigidity and stiffness and resists slack and backlash by mounting swashplate actuators to a flange rigidly secured to the mast, and may be monolithic therewith. A mast tilt actuator and a mast pivot may secure to the mast flange, with vibration suppressors. A shroud may provide a sealed fluid path for airflow therethrough encircling portions of the rotor hub and restricting airflow between the rotor hub and shroud. A rotor cavity, in fluid communication with blade ducts (hollow portions of the blade spars), and either or both contoured to reduce pressure losses, may assist in temperature control, and may feed into tip jets on the blades.