Modeling The Drag Forces Of Porous Media Acoustics
The drag forces controlling the amount of relative flow induced in a fluid-saturated porous material by a mechanical wave are modeled here from first principles. Specifically, analytical expressions are derived for the drag force in material models that possess variable-width pores; Le., pores that...
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Technical Report |
| Published: |
Massachusetts Institute of Technology. Earth Resources Laboratory
2012
|
| Online Access: | http://hdl.handle.net/1721.1/75188 |
| _version_ | 1826203788700024832 |
|---|---|
| author | Pride, Steve |
| author2 | Massachusetts Institute of Technology. Earth Resources Laboratory |
| author_facet | Massachusetts Institute of Technology. Earth Resources Laboratory Pride, Steve |
| author_sort | Pride, Steve |
| collection | MIT |
| description | The drag forces controlling the amount of relative flow induced in a fluid-saturated
porous material by a mechanical wave are modeled here from first principles. Specifically, analytical expressions are derived for the drag force in material models that possess variable-width pores; Le., pores that have widths that vary with distance along their axis. The dynamic (complex, frequency-dependent) permeability determined for
such a variable-width pore model is compared to estimates made using the models of
Johnson, Koplik, and Dashen (JKD) and of Biot. Both the JKD model and the Biot
model underestimate the imaginary part of the dynamic permeability at low frequencies
with the amount of discrepancy increasing with the severity of the convergent/divergent
flow; Le., increasing with the magnitude of the maximum pore-wall slope relative to
the channel axis. It is shown how to modify the JKD model to obtain proper low-frequency
behavior; however, even with this modification, discrepancies still exist near
the transition frequency that separates viscous-force-dominated flow from inertial-force-dominated flow. The amount of discrepancy is again a function of the severity of the
convergent/divergent flow (maximum pore-wall slope). |
| first_indexed | 2024-09-23T12:43:03Z |
| format | Technical Report |
| id | mit-1721.1/75188 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T12:43:03Z |
| publishDate | 2012 |
| publisher | Massachusetts Institute of Technology. Earth Resources Laboratory |
| record_format | dspace |
| spelling | mit-1721.1/751882019-04-12T20:31:19Z Modeling The Drag Forces Of Porous Media Acoustics Pride, Steve Massachusetts Institute of Technology. Earth Resources Laboratory Pride, Steve The drag forces controlling the amount of relative flow induced in a fluid-saturated porous material by a mechanical wave are modeled here from first principles. Specifically, analytical expressions are derived for the drag force in material models that possess variable-width pores; Le., pores that have widths that vary with distance along their axis. The dynamic (complex, frequency-dependent) permeability determined for such a variable-width pore model is compared to estimates made using the models of Johnson, Koplik, and Dashen (JKD) and of Biot. Both the JKD model and the Biot model underestimate the imaginary part of the dynamic permeability at low frequencies with the amount of discrepancy increasing with the severity of the convergent/divergent flow; Le., increasing with the magnitude of the maximum pore-wall slope relative to the channel axis. It is shown how to modify the JKD model to obtain proper low-frequency behavior; however, even with this modification, discrepancies still exist near the transition frequency that separates viscous-force-dominated flow from inertial-force-dominated flow. The amount of discrepancy is again a function of the severity of the convergent/divergent flow (maximum pore-wall slope). 2012-12-04T14:46:35Z 2012-12-04T14:46:35Z 1992 Technical Report http://hdl.handle.net/1721.1/75188 Earth Resources Laboratory Industry Consortia Annual Report;1992-05 application/pdf Massachusetts Institute of Technology. Earth Resources Laboratory |
| spellingShingle | Pride, Steve Modeling The Drag Forces Of Porous Media Acoustics |
| title | Modeling The Drag Forces Of Porous Media Acoustics |
| title_full | Modeling The Drag Forces Of Porous Media Acoustics |
| title_fullStr | Modeling The Drag Forces Of Porous Media Acoustics |
| title_full_unstemmed | Modeling The Drag Forces Of Porous Media Acoustics |
| title_short | Modeling The Drag Forces Of Porous Media Acoustics |
| title_sort | modeling the drag forces of porous media acoustics |
| url | http://hdl.handle.net/1721.1/75188 |
| work_keys_str_mv | AT pridesteve modelingthedragforcesofporousmediaacoustics |