Experimental Research of a Vortex Induced Piezoelectric Energy Converter (VIPEC) with a Small Prototype in the Water Tunnel

A device combined vortex induced vibration and piezoelectric material, called “Vortex Induced Piezoelectric Energy Converter (VIPEC)” was proposed. It consists of a circular cylinder, a pivoted plate and several piezoelectric patches, and converts fluid kinetic energy into electric power through the driving force on the plate due to shedding vortices from the circular cylinder. A small VIVPEC prototype was manufactured and tested in a laboratory water tunnel. Various testing cases with different flow velocities and plate lengths were carried out. Output voltage signals were acquired and filtered using a fourth order Butterworth bandpass filter. It reveals that the shedding frequency comes to its maxima at the dimensionless plate length $L^{\ast}=1.5$ for different velocities and the maximal open circuit output voltage reaches 2.2 mV at the plate length be 2.5 times the cylinder's diameter and the flow velocity $U$ be 2.3 m/s. The voltage responses reach their peaks at $U=2$ m/s, and get their nadirs at $U=1$ m/s between a resistance load range of $5\ \mathbf{k}\pmb{\Omega}$ and $40\ \mathbf{k}\pmb{\Omega}$. The maximum voltage is 1.13 mV at $L^{\ast}=2.5,\ U=2$ m/s with a resistance load of $10\ \mathbf{k}\pmb{\Omega}$. The tests demonstrate the feasibility of VIPEC.