Variable Incidence Wing Compound Rotorcraft
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional helicopters face challenges in achieving variable mast incidence for enhanced forward thrust and lift augmentation, often requiring complex systems or flexible drive shafts, and struggle with retreating blade stall and rotor flapping at high speeds.
Innovation Solution
A twin-rotor side-by-side compound rotorcraft with a variable incidence wing system, where counter-rotating rotors are mounted near wing tips, allowing for mast tilt and wing rotation to optimize thrust and lift, reducing rotor flapping and retreating blade stall through a common lift-propulsive system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a tilting mast/transmission assembly is used to achieve variable mast incidence, then forward thrust is improved, but a flexible drive shaft is required which increases device complexity
Solution Approach 1:
The mast and transmission assembly is made tiltable relative to the fuselage, allowing dynamic adjustment of mast incidence angle to optimize forward thrust. This dynamic configuration enables the system to adapt to different flight conditions without requiring flexible drive shafts, as the rigid components can pivot together as a unit.
2Force
If a tilting mast/transmission/engine assembly is used to achieve variable mast incidence, then forward thrust is improved, but a complicated mounting system is required which increases device complexity
Solution Approach 1:
The mast, transmission, and engine assemblies are merged into a single tiltable unit that moves together relative to the fuselage. This integration simplifies the mounting system compared to separate tilting mechanisms, as only one mounting interface is needed to control the collective motion of all three components.
3Force
If separate wings are added to provide lift augmentation, then lift capability is improved, but an independent propulsive device is required which increases device complexity
Solution Approach 1:
The main rotor system is designed to perform multiple functions: it provides both primary lift and auxiliary propulsive force. By tilting the mast assembly, the rotor can generate forward thrust in addition to lift, eliminating the need for separate propulsive devices and reducing overall system complexity while maintaining enhanced lift capability through the added wings.
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
This configuration enhances hover lift efficiency, reduces rotor loads, and enables higher speeds by providing ancillary lift and propulsive force, eliminating the need for a tail rotor and simplifying the mounting system, while allowing for efficient storage and transport.
Implementation Method 1
utilizing a tilting of the mast/transmission assembly realtive to the fuselage and engine; or (2) utilizing a tilting mast/transmission/engine assembly
Implementation Method 2
Each rotor has multiple rotor blades and is powered by an engine. Power generated by the engine is transmitted to the rotors via shafts, transmissions, and gear boxes.
Data Source
Figure 1A~1B
Figure 2~4
Figure 5~8
AI summary
A twin-rotor side-by-side compound rotorcraft has a fuselage and variable incident wing assembly that pivots relative to fuselage. The aircraft also has landing gear assembly and a tail fin assembly. The variable incident wing assembly is pivotally attached to the fuselage, and includes wing members, engines fixedly mounted to the wing members or another area of the rotorcraft, and a mast attached at a fixed angle relative to the wing members. Then engines may also be located near the fuselage or another area of the rotorcraft. The variable incident wing assembly is capable of pivoting about a pivot axis, thereby allowing mast orientation in at least a hover mast position and a forward flight mast position. The rotors provide additional forward thrust and the wings provide additional lift, when the mast is in the forward flight mast position.