Frequency-dependent streaming potential experiments of porous transducer in liquid circular angular accelerometer

Abstract

The classical Helmholtz-Smoluchowski equation is broadly used to characterize the relationship among the DC streaming potential coupling coefficient, the properties of the porous medium and the pore fluid, such as the zeta potential, fluid dielectric, conductivity and permittivity under the steady-state fluid flow. However, there is a frequency-dependent streaming potential through both sides of a transducer, which is one kind of porous media sintered by glass beads with different diameters and embedded in the liquid circular angular accelerometer. In order to increase the streaming potential signal, broaden the bandwidth of the accelerometer, and analyze the influence factors, we present a novel measurement system to determine streaming potential coupling coefficient of those transducers, which provides a sinusoidal pressure-driven fluid flow for transducers below 320 Hz. We have measured dynamic streaming potential coupling coefficients of 4 types of transducers by this device, and the results are well consistent with the theoretic model. For magnitude anomalies of the frequency response of the streaming potential coupling coefficient, we analyze the relationship among the cut-off frequency, permeability, and the mean particle size. It is proved that the cut-off frequency is inversely proportional to the mean particle size or permeability.