A Self-Powered and Low Pressure Loss Gas Flowmeter Based on Fluid-Elastic Flutter Driven Triboelectric Nanogenerator

Abstract

A self-powered and low pressure loss gas flowmeter is presently proposed and developed based on a membrane's flutter driven triboelectric nanogenerator (TENG). Such a flowmeter, herein named "TENG flowmeter", is made of a circular pipe in which two copper electrodes are symmetrically fixed and a nonconductive, thin membrane is placed in the middle plane of the pipe. When a gas flows through the pipe at a sufficiently high speed, the membrane will continuously oscillate between the two electrodes, generating a periodically fluctuating electric voltage whose frequency can be easily measured. As demonstrated experimentally, the fluctuation frequency (<i>f</i>_F) relates linearly with the pipe flow mean velocity (<i>U</i>_m), i.e., <i>f</i>_F <i>U</i>_m; therefore, the volume flow rate <i>Q</i> (=<i>U</i>_m <i>A</i>) = C₁<i>f</i>_F + C₂, where C₁ and C₂ are experimental constants and <i>A</i> is the pipe cross-sectional area. That is, by the TENG flowmeter, the pipe flow rate <i>Q</i> can be obtained by measuring the frequency <i>f</i>_F. Notably, the TENG flowmeter has several advantages over some commercial flowmeters (e.g., vortex flowmeter), such as considerable lower pressure loss, higher sensitiveness of the measured flow rate, and self-powering. In addition, the effects of membrane material and geometry as well as flow moisture on the flowmeter are investigated. Finally, the performance of the TENG flowmeter is demonstrated.