Segmented Rotor Blade Flap Actuation for Centrifugal Stress Reduction
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Solution Overview
Problem
Rotor blades in rotary-wing aircraft experience noise and vibration due to air turbulence, leading to material fatigue and reduced service life, with existing solutions facing issues of actuator failure from centrifugal strain and complex mechanical stress.
Innovation Solution
A rotor blade design featuring a reversibly bendable carrier element with segmented flaps, where actuators are integrated directly onto the carrier element, reducing mechanical stress by distributing centrifugal force and allowing continuous deformation, and incorporating a flexible filling material for smooth contour transition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If piezoelectric actuators are arranged near the trailing edge to control rotor blade flap, then the flap can be effectively actuated, but the actuators are subjected to high centrifugal strain and tensile forces that can lead to actuator failure
Solution Approach 1:
The rotor blade flap is divided into multiple segments along the spanwise direction, with actuators assigned to specific segments. This segmentation distributes the centrifugal force and tensile loads across multiple smaller actuator units rather than concentrating them on a single large actuator, thereby reducing the stress on each individual actuator and improving overall reliability while maintaining effective flap control
2Object-affected harmful factors
If a rigid rotor blade flap is used to reduce noise and vibration, then aerodynamic performance is improved, but mechanical wear increases due to joints and relative movement
Solution Approach 1:
The invention employs an elastically movable rotor blade flap that can dynamically adapt its shape through piezoelectric actuators, replacing the traditional rigid flap with fixed joints. This dynamic design allows the flap to change curvature and position continuously, reducing mechanical wear from repetitive joint movements while maintaining noise and vibration reduction effectiveness
Solution Approach 2:
The invention replaces traditional mechanical joint systems with piezoelectric actuators that directly deform the flap structure. This substitution eliminates the need for physical joints and connecting mechanisms, thereby reducing mechanical wear and friction while achieving the same noise and vibration mitigation goals
3Duration of action of stationary object
If the rotor blade flap is made elastically movable to reduce wear, then service life is extended, but the system becomes more complex with additional skin deformations
Solution Approach 1:
The invention merges the flap control function with the existing skin structure by integrating piezoelectric actuators directly into the skin layers. The upper and lower skins work together with the actuators to achieve flap deformation, eliminating the need for separate rigid flap structures and reducing overall system complexity while extending service life
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 design reduces actuator stress, enhances aerodynamic performance, and extends the lifespan of rotor blades by minimizing wear and maintaining smooth contour changes during flap deflection, while allowing for easy maintenance and detachment.
Implementation Method 1
piezoelectric actuators which are arranged at a distance from the flap in a profile depth direction in a front profile region of the rotor blade profile body. The piezo actuator generates actuating forces and transmits them to the rotor blade flap
Data Source
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AI summary
The invention relates to a rotor blade (20), in particular for a rotary wing aircraft. The invention is characterised by the following: an aerodynamic rotor blade profile with a profiled leading edge region (21), a profile base body (20a) comprising a profile core and a lower and upper skin (30) that encases the profile core (22) and a profiled trailing edge region (23) with a trailing edge (40); a reversibly flexible support element (26), the first end of which can be fixed to an end region of the profile base body (20a) that is oriented towards the trailing edge (40) and the second end of which projects freely out of the profile base body (20a) and the end region thereof towards the trailing edge (40), forming a movable rotor-blade flap (24); and several actuators (35) that are operatively connected to the projecting second end of the reversibly flexible support element (26), whereby a modification in the length of the actuators causes an arc-shaped deflection of the flap. The second end of the reversibly flexible support element (26) forming the rotor-blade flap (24) is divided into several segments, when viewed in the direction of the span (S), by means of cut-out sections (34) and at least one actuator (35) is assigned to each segment.