Wing-Rotor Closure Means for Boundary Layer Control
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Solution Overview
Problem
Existing VTOL aircraft designs face challenges with noise, emissions, and poor aerodynamic behavior due to the use of turbine engines and tilt rotors, which limit their usability in urban areas and reduce lift and increase weight.
Innovation Solution
A wing-rotor arrangement with a rotor integrated into the wing, featuring partially permeable closure means that allow air suction and blowing, reducing boundary layer thickness and increasing lift by managing airflow, thereby enhancing aerodynamic properties and energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a rotor is integrated into the wing with closed closure means, then the aerodynamic properties deteriorate due to surface irregularities and boundary layer transition, but the rotor structure provides vertical thrust capability
Solution Approach 1:
The closure means are designed with porous structure that allows controlled air permeability. This enables the closure means to maintain structural integrity for rotor integration while allowing air flow through them, preventing boundary layer separation and maintaining smooth aerodynamic flow over the wing surface.
Solution Approach 2:
The patent utilizes pneumatic principles by controlling air flow through the porous closure means. The air flow management system exploits pressure differentials to draw air through the closure means, actively managing the boundary layer to prevent turbulence and maintain laminar flow, thereby preserving aerodynamic performance.
2Force
If turbine engines are used for vertical takeoff and landing, then vertical thrust is achieved, but noise and exhaust emissions make urban use impossible
Solution Approach 1:
The patent replaces turbine engine propulsion with rotor-based mechanical propulsion. The rotors are driven by electric or other non-turbine power sources, eliminating the combustion process that generates noise and exhaust emissions. This substitution maintains vertical thrust capability while removing harmful environmental factors.
3Adaptability or versatility
If tiltrotors are used for VTOL, then vertical and horizontal flight is enabled, but high technical requirements for rotor blade control and movable mountings increase complexity
Solution Approach 1:
The patent integrates rotors directly into the wing structure, making the wings themselves multi-functional. The wings serve both as lift-generating surfaces during horizontal flight and as mounting structures for vertical thrust rotors. This eliminates the need for separate tiltrotor mechanisms and complex movable mountings, reducing overall system complexity while maintaining VTOL capability.
4Force
If louvre arrangement is closed for flight operations, then wing lift is sufficient, but aerodynamic behavior deteriorates due to gaps and irregularities
Solution Approach 1:
The closure means utilize porous material properties to allow controlled air permeability. This prevents the formation of disruptive gaps and irregularities that would cause boundary layer separation. The porous structure maintains a smooth effective surface while allowing necessary air flow, preserving both lift generation and aerodynamic efficiency.
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 solution improves aerodynamic performance, reduces air resistance, and increases lift, enabling better flight characteristics and energy efficiency while allowing vertical takeoff and landing capabilities without the drawbacks of previous designs.
Implementation Method 1
a rotor arranged in a wing (22). The thrust direction of the rotor (22) is aligned largely perpendicular to the direction of airflow to the wing (11)
Implementation Method 2
The closure means (3) are partially permeable to air when closed
Implementation Method 3
negative pressure in the area of the rotor's inlet opening in the wing can be used to suck air out of the upper surface of the wing. This advantageously reduces the thickness of the decelerated boundary layer on the surface of the wing
Implementation Method 4
air is blown out of the underside of the wing, which advantageously stabilizes the boundary layer and can significantly increase the wing's lift
Implementation Method 5
The wings of the wing-rotor assembly are used during flight, in which the aircraft receives its lift from the airflow against the wing
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
In the lifting surface (11), the rotor (22) of the lifting surfaces/rotor assembly (1) has an inlet opening (21) that can be closed by a closing means (3) and an outlet opening (25) that can be closed by a closing means (3). The closing means (3) are partially air-permeable in the closed state. When the rotor is running (22) and the closing means (3) are closed, this air-permeability allows for a targeted influencing of the aerodynamic properties of the lifting surface (11). In this way, a suctioning away of the air on the upper side of the lifting surface can be achieved by an underpressure in the region of the inlet opening (21) of the rotor (22) in the lifting surface (11), and simultaneously, a blowing out of air on the underside of the lifting surface can be achieved by an overpressure in the region of the outlet opening (25). Advantageously, in this way, the decelerated boundary layer on the surface of the aerofoil is reduced in thickness (δG) in the region of the inlet opening (21) via suctioning, and a high-energy outer layer can be applied to the profile of the lifting surface (11). More advantageously, the air resistance of the lifting surface (11) can thereby be reduced and the uplift thereof increased, which leads to improved flight characteristics and higher energy efficiency of an aircraft with a lifting surfaces/rotor assembly (1). Particularly advantageously, the suctioning occurs in the region of the closing means (3) of the inlet opening (21) of the rotor (22), whereby otherwise, due to unevenness caused by the closing means (3), there is a thicker boundary layer (δG) on the surface.