A flow sensing method of power spectrum based on piezoelectric effect and vortex-induced vibrations

This study introduces a piezoelectric sensor based on vortex-induced vibrations. Such sensor module is endowed with a piezoelectric cantilever and cylinder, which can be used to measure the wind flow from the characteristic signals of vortex. In contrast to the conventional sensors using peak-to-peak, zero-to-peak or root-mean-square voltages as the characteristics of the vortex, the proposed sensor takes advantage of the power spectrum in the vortex frequency as the sensing intensity of the characteristic vortex, contributing to successfully sensing weak flow signals. Then, we propose a fluid-solid-electric coupling finite element method to investigate the relationship between the power spectrum and the geometrical parameters (including size and position). The calculated and experimental results show that increasing the cylinder's diameter can linearly enhance the optimal sensing region and the power spectrum, but the region does not change with altering the amplitude of wind velocity. In our experiment, the sensor can effectively test the wind velocity of 1.5 m/s, which is difficult to be measured by traditional sensors. Therefore, this fluid-solid-electric coupling calculation method can be used to design the structure of flow sensor.