Apparatus to Determine the Complex Mass of a Viscous Fluid Contained in a Rigid Porous Solid from Acoustic Pressure Measurements.

摘要

Two experimental techniques to determine the frequency-dependent complex mass of a viscous fluid contained in a rigid porous solid are investigated. In one technique the moving mass of the fluid is by its effect on the measured input electrical impedance of a moving coil transducer. In the second technique the moving mass is extracted from the measured acoustic pressure required for the fluid to oscillate with a known amplitude through the solid frame. A description of the apparatus and preliminary results using the pressure method as well as a comparison of the two techniques are presented. Keywords: Acoustic impedance; Acoustic coupler; Complex mass density; Fluid saturated; Porous media; Theses. (jhd)