On the Electroacoustic Transformation Method Based on Electrokinetic Phenomena

Abstract

In a linear and nonlinear approximation (laminar regime), physical and mathematical models are proposed to describe the functioning mechanism of a new type of acoustic transducer. Brief information is given on the electrokinetic phenomenon of electroosmosis. The necessary equations are presented for describing acoustic fields caused by electrokinetic phenomena: the presence of a double electric layer and the total applied electric field consisting of a constant field and a field that carries acoustic information. The equations for a fluid in a circular cylindrical capillary are considered as applied to calculating the hydrodynamics of a stationary electroosmotic process and a harmonic acoustic process. Theoretically, with a computational model, and experimentally, it is shown that taking into account the nonlinearity of the stationary process leads, in contrast to the linear stationary process, to transfer of the energy of the constant electric field to the acoustic field caused by an alternating electric field. The results, with certain restrictions, are true for a wide class of porous structures. Experimentally, for a paper membrane as a capillary-porous structure, pumping was used to amplify the first harmonic of the acoustic pressure from 5.9 to 28 times for different values of the alternating electric field amplitude. The theoretical and experimental results obtained in this study make it possible to solve the priority scientific and technical problem of designing and creating new types of acoustic emitters.