Hexagonal Strain Amplification Structure for Synthetic Jet Actuator
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Solution Overview
Problem
Existing synthetic jet actuators require amplification systems that increase translational mass, limiting their efficiency and frequency of operation, particularly when using piezoelectric actuators for aerodynamic control and flow management.
Innovation Solution
A mechanical amplification structure with a hexagonal frame and flexible joints connects piezoceramic actuators to a center shaft, allowing orthogonal motion without interfering with the actuation assembly, reducing moving mass and enhancing amplification through coupled mechanical and acoustic resonance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a basic flexible rombus structure is used for amplification, then motion amplification is achieved, but the entire flexure including the piezoelectric stack translates during activation, increasing translational mass
Solution Approach 1:
The invention extracts the piezoelectric stack from the translating motion path by using a collared shaft that passes through the actuator assembly. The shaft is constrained to move only in the longitudinal direction while the piezoelectric stack remains stationary relative to the transverse plane, separating the amplification function from the translating mass.
Solution Approach 2:
The invention introduces a new dimensional constraint by using a collared shaft configuration where the shaft can move longitudinally through the actuator assembly without the piezoelectric stack translating transversely. This dimensional separation allows amplification in one dimension while preventing mass translation in another dimension.
2Productivity
If the piezoelectric stack is constrained at one vertex with motion output at the second vertex, then amplification is created, but the entire flexure structure must translate, limiting frequency of operation
Solution Approach 1:
The piezoelectric stack is extracted from the translating motion path and held stationary by the collared shaft configuration, allowing the amplification mechanism to operate without moving the heavy piezoelectric mass, thereby increasing the frequency of operation.
Solution Approach 2:
The invention creates a dynamic system where the collared shaft can move independently in the longitudinal direction while the piezoelectric stack remains fixed in the transverse plane, enabling high-frequency operation by decoupling the mass translation from the amplification motion.
3Power
If amplification systems are employed for piezoelectric actuators, then enhanced operation is achieved, but translational mass increases, reducing efficiency
Solution Approach 1:
The piezoelectric stack is extracted from the translating mass by using a collared shaft that passes through the actuator assembly, allowing the amplification transfer function to be maximized while the heavy piezoelectric mass remains stationary, thereby improving efficiency.
Solution Approach 2:
The invention uses dimensional separation to allow amplification in the longitudinal direction while preventing transverse translation of the piezoelectric stack, maximizing the amplification transfer function without increasing translational mass.
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 achieves significant displacement amplification, minimizing translational mass and maximizing the transfer function, resulting in higher air velocities and forces through the synthetic jet orifice, with a displacement amplification factor of up to 10 and resonant amplification of approximately 5, while maintaining axial alignment and reducing operational frequency.
Implementation Method 1
Activation of the piezoelectric elements provides lateral extension or contraction of the actuation assembly
Implementation Method 2
The frame incorporates a plurality of rigid beams connected together by flexible joints
Implementation Method 3
coupled mechanical and acoustic resonance
Implementation Method 4
coupled mechanical and acoustic resonance
Data Source
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AI summary
A strain amplification structure has a frame with a hexagonal structure incorporating a plurality of rigid beams (16a) that are connected to opposing end beams by a plurality of flexible joints (24). A piezoceramic actuator assembly (26) is connected to the opposing end beams having a collar (32)including an opening. A shaft (18) providing an output is connected to the plurality of rigid beams with flexible joints and passes through the opening in the collar (32) for non-interfering motion orthogonal to the actuator assembly.