Low-speed airflow energy acquiring apparatus and method based on flexible flutter effects

Abstract

The invention discloses a low-speed air flow energy acquiring apparatus and method based on flexible flutter effects. The apparatus herein includes a flexible and elastic piezoelectric film belt which is tightly fixed between two pedestals. The method includes the following steps: 1. assembling a lower speed airflow energy acquiring apparatus which is based on flexible flutter effects; 2. the flexible and elastic piezoelectric film belt generating quasi-sinusoidal vibration with fixed frequencies when subject to transverse wind; 3. introducing a critical damping ratio [zeta]h in the vertical direction and a critical damping ratio [zeta][alpha] in the deflecting direction, and a fixed frequency [omega]h and [omega][alpha] of the two directions; and 4. introducing an aerodynamic derivative Hi and Ai to describe the relationship between structural features and wind speed of an elastic body. A system absorbs energy from ambient airflow, generates steady vibration which can acts on an electromagnetic resonance unit or a flexible piezoelectric material, and a steady output electricity is generated. The electricity is stored in a super capacitor or a battery for supplying power to sensor nodes. According to the invention, the apparatus can generate power automatically and is environmental-friendly.

Description

technical field [0001] The invention relates to a low-speed airflow energy collection device and method based on the flexible flutter effect, in particular to an energy collection device and method based on the aerodynamic flutter effect, which can efficiently convert low-speed airflow into electrical energy for use in urban construction wireless sensor nodes between objects or indoor ventilation ducts. Background technique [0002] Flutter is a dynamic instability phenomenon that occurs at a certain wind speed. It is mainly caused by the self-excited force generated by the interaction between the airflow and the structure. The existence of the self-excited force makes the damping and stiffness of the system The nature changes, resulting in a total negative damping at a certain wind speed, resulting in the continuous increase of the vibration energy of the structure. When the critical wind speed is reached and within the wind speed that the structure can withstand, the struc...

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Problems solved by technology

[0003] At present, the research on flutter is mainly concentrated in bridge wind engineering and wing design of aerospace engineering. The research direction is mainly to explore the occurrence conditions of flutter to reduce the occurrence of flutter accidents. There is no special systematic research to discuss how to enhance And use the flutter effect to obtain energy from the airflow, especially the positive feedback self-excited force derived from the coupling effect of the moving structure and the airflow in the flutter effect. Most of the acquisition methods use the airflow to drive the wing-like structure, and then compress the piezoelectric beam, and obtain energy through the positive piezoelectric method. The mechanical structure of this type of method is relatively complicated. Piezoelectric materials have low energy conversion efficiency under low-frequency vibration, so they are not suitable for low-speed airflow energy harvesting

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