Abstract
Air-filled porous media have been characterized acoustically using level difference measurements and an impedance model that depends on a pore-shape factor, porosity, tortuosity, and bulk flow resistance. Least-squares fitting of level difference spectra only allows two of the above parameters to be independently determined. Probe microphone measurements have been used to determine the propagation constant in both washed sand and glass beads. Values of tortuosity calculated from probe microphone measurements were used in the analysis of level difference data to determine porosity and bulk flow resistance. An average pore-shape factor is used in the analysis. For the unconsolidated porous media used, the effect of the pore-shape factor variation was within the error range of the measurement. The availability of both probe microphone and level difference data has also allowed for the comparison of porosity and flow resistance values calculated from each set of data. There are some discrepancies between the frequency dependence of the model and the probe microphone data. [Work supported by USDA.]
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
