VTOL Air Vehicle Transition with Dual Propulsion and High-Lift Wings
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Solution Overview
Problem
VTOL fixed wing air vehicles require significant energy for vertical take-off and landing, and electrical propulsion systems contribute substantial weight due to the need for large electrical batteries to provide power for vectored flight maneuvers.
Innovation Solution
A method for transitioning a VTOL fixed wing air vehicle from forward speed mode to hover mode using a combination of high lift, mild stall wings and dual propulsion systems, where one system provides thrust for aerodynamic flight and the other for vectored thrust, manipulating angle of attack and thrust vectors to maintain controlled flight during the transition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If electrical batteries are used to provide large amounts of electrical power for vertical take-off and landing, then the air vehicle can achieve vectored flight capability, but the battery weight contributes significantly to the overall vehicle weight
Solution Approach 1:
The propulsion system is divided into two independent systems: a first propulsion system with a first thrust vector for aerodynamic powered flight, and a second propulsion system with a second thrust vector for vectored flight. This segmentation allows each system to be optimized for its specific function, reducing the overall power requirements and battery weight needed for vectored flight operations.
Solution Approach 2:
The air vehicle dynamically transitions between flight modes by manipulating the angle of attack and thrust vectors. During transition from forward speed mode to hover mode, the system dynamically adjusts the angle of attack to provide aerodynamic lift while simultaneously adjusting the second thrust vector to provide vertical lift, enabling efficient mode transitions without requiring excessive power reserves.
2Adaptability or versatility
If the air vehicle uses swivel type propulsion units to transit between aerodynamic powered flight and zero forward speed, then it can achieve VTOL capability, but the mechanical complexity of swivel mechanisms increases device complexity
Solution Approach 1:
Instead of using a single swivel-type propulsion unit that must mechanically reorient, the system segments propulsion into two fixed-oriented systems: one optimized for forward flight and another for vertical thrust. This eliminates the need for mechanical swiveling mechanisms while maintaining VTOL capability through coordinated operation of both systems.
Solution Approach 2:
The second propulsion system, while primarily designed for vertical thrust, can also provide braking force during transition by manipulating its thrust vector. This multi-functionality reduces the need for additional mechanical components for braking, simplifying the overall system while maintaining versatility.
3Force
If the air vehicle operates at high angle of attack during transition, then aerodynamic lift is maximized, but the risk of flow separation over the fixed wings increases
Solution Approach 1:
The system changes the operating parameters of the fixed wing arrangement by utilizing high lift, mild stall wing geometry. These wings are specifically designed to maintain attached flow at higher angles of attack compared to conventional wings, allowing the vehicle to operate at elevated angles of attack during transition while minimizing flow separation and maintaining reliable aerodynamic lift.
4Loss of time
If the transition from forward speed mode to hover mode is performed quickly, then the time required for mode transition is reduced, but the energy requirements and control precision demands increase
Solution Approach 1:
The transition process is made dynamic and continuous through coordinated manipulation of angle of attack and thrust vectors. The system follows a transient path that smoothly transitions aerodynamic lift to vertical vectored thrust, allowing rapid mode changes while distributing energy requirements across both propulsion systems and maintaining control stability throughout the transition.
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
Minimizes the time and energy required for transitioning between flight modes, reducing the need for large batteries and overall vehicle weight by utilizing the vectored thrust for braking and lift compensation.
Implementation Method 1
manipulating a first magnitude of angle of attack of the air vehicle and a second magnitude of forward speed of the air vehicle during said transitioning to provide a corresponding aerodynamic lift component
Implementation Method 2
conditions of separated flow over the fixed wings and conditions of partially and/or fully attached flow over the fixed wings
Implementation Method 3
said second propulsion system is configured for providing a second thrust to the air vehicle at a second thrust vector, the second thrust being at least sufficient for enabling vectored thrust flight to the air vehicle at least in said hover mode
Implementation Method 4
enabling the spatially fixed second thrust vector to provide an aft braking force during said transition mode
Data Source
AI summary
A VTOL-type air vehicle is transitioned from forward speed mode to hover mode via a transient path in transition mode. The air vehicle includes first and second propulsion systems, and high lift, mild stall fixed wings. The first propulsion system can provide a first thrust (sufficient for enabling powered aerodynamic flight) at a first thrust vector. The second propulsion system can provide a second thrust (sufficient for enabling vectored thrust flight) at a second thrust vector, which is spatially fixed with respect to the air vehicle at least during transitioning. The transient path includes, during transitioning, manipulating a first magnitude of angle of attack and a second magnitude of forward speed to provide a corresponding aerodynamic lift component, and concurrently manipulating a third magnitude of the second thrust to provide a vertical vectored thrust component corresponding to the first magnitude of angle of attack. A summation of the aerodynamic lift component and vertical vectored thrust component is sufficient for enabling the air vehicle to remain in controlled flight in transition mode.