Tilt-Rotor and Stacked Vertical Rotor Layout for VTOL Wash Reduction
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Solution Overview
Problem
Existing aircraft designs face challenges in configuring a propulsion system for efficient VTOL flight and high-speed cruise while maintaining system redundancy and minimizing noise and drag.
Innovation Solution
A flying vehicle design featuring a first rotor assembly with a tilt-rotor and a second rotor assembly comprising a stacked plurality of vertical thrust rotors, positioned longitudinally and vertically aligned, with the stacked rotors on one side of a pylon, allowing for efficient thrust delivery and reduced wash interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a tilt-rotor is used for efficient cruise flight, then cruise efficiency is improved, but the rotor may generate wash that interferes with downstream vertical thrust rotors
Solution Approach 1:
The patent positions the vertical thrust rotors in a stacked arrangement along the longitudinal axis, utilizing the longitudinal dimension to spatially separate the tilt-rotor and vertical thrust rotors. This dimensional arrangement allows the tilt-rotor to operate efficiently in cruise mode while the downstream vertical thrust rotors are positioned far enough away to minimize wash interference, thus resolving the contradiction between cruise efficiency and wash interference.
2Object-generated harmful factors
If stacked vertical thrust rotors are positioned close together, then noise and drag are reduced, but the likelihood of blade vortex interaction increases
Solution Approach 1:
The patent applies local quality by differentiating the operational characteristics of each rotor in the stack. The upstream vertical thrust rotor operates in relatively undisturbed air, while the downstream vertical thrust rotor is positioned to operate in the wake of the upstream rotor. This localized arrangement optimizes the balance between minimizing overall noise and drag while managing blade vortex interaction through strategic positioning of individual rotors within the stack.
3Object-generated harmful factors
If the tilt-rotor is positioned to avoid wash effects on vertical thrust rotors, then wash interference is reduced, but the overall aircraft length increases
Solution Approach 1:
The patent utilizes the longitudinal dimension to accommodate the increased spacing between the tilt-rotor and vertical thrust rotors. By extending the aircraft length, the design prioritizes minimizing wash interference over compactness, allowing the tilt-rotor and vertical thrust rotors to be positioned far enough apart to reduce harmful aerodynamic interactions while maintaining functional performance.
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
Enhances flight efficiency, reduces noise, and minimizes drag by mitigating wash effects and enabling dynamic configuration options, while maintaining system redundancy and reducing weight and complexity.
Implementation Method 1
a first rotor assembly and optionally a second rotor assembly pylon arranged to mount the second rotor assembly to the remainder of the flying vehicle, where the first rotor assembly and the second rotor assembly are optionally located so that they are spaced in a longitudinal direction of the flying vehicle
Implementation Method 2
the second rotor assembly optionally comprises a stacked plurality of substantially vertical thrust rotors optionally mounted to the pylon so as to be substantially to the same side of the pylon
Implementation Method 3
there is an axis, parallel to the longitudinal axis of the flying vehicle, along which a projection of one or other of the first and second rotor assemblies towards the other, would at least partially overlap that other. Relevant degrees of alignment may be those sufficient for potential non-negligible wash interception by a downstream of the first and second rotor assemblies generated by an upstream of the first and second rotor assemblies
Data Source
AI summary
A flying vehicle includes a first rotor assembly, a second rotor assembly and a second rotor assembly pylon arranged to mount the second rotor assembly to the remainder of the flying vehicle. The first rotor assembly and the second rotor assembly are located so that they are spaced in a longitudinal direction of the flying vehicle and so they are substantially on a vertical plane that is parallel to a vertical plane aligned with a longitudinal axis of the flying vehicle. The first rotor assembly includes a tilt-rotor arranged to tilt between delivery of substantially vertical flight thrust and substantially conventional flight thrust. The second rotor assembly includes a stacked plurality of substantially vertical thrust rotors mounted to the pylon so as to be substantially to the same side of the pylon.