Predicting Airflow Rates in the Coarse Layer of Passive Dry Barriers
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 128, Issue 4
Abstract
Laboratory experiments were conducted with steady wind velocities to measure pressure drops in pipes used to ventilate passive dry barriers. Two vent pipe diameters (100 and 150 mm) and several pipe end geometries were tested. Nondimensional ventilator equations were developed using the pressure drop data that, when combined with Darcy’s law, can be used to estimate airflow rates in passive dry barriers. A field experiment was conducted to verify the laboratory results. Comparisons were also made between flow rates predicted using the airflow rate equations and flow rates measured in two field-scale tests of dry barriers, one of which was constructed by the writers. Results of the laboratory tests indicate that a unique ventilator equation exists for each pipe end geometry, and that more than one equation may exist if the pipe end is not symmetrical (i.e., the pressure drop depends on wind direction relative to the pipe end). The field experiment indicated that the equations developed based on the laboratory data are in general agreement with average field conditions, but more scatter exists in the field due to varying wind velocities. Good correspondence exists between predicted flow rates and those measured in the field scale tests of passive dry barriers.
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References
Albrecht, B. (2001). “Passive dry barrier air circulation and mass transfer.” PhD dissertation, University of Wisconsin-Madison, Wis.
Ankeny, M., Coons, L., Majumdar, N., Kelsey, J., and Miller, M. (1997). “Performance and cost considerations for landfill caps in semi-arid climates.” Proc., Landfill Capping in the Semi Arid West: Problems, Perspective, and Solutions, Idaho Fall, Id. 263.
Bear, J. (1972). Dynamics of Fluids in Porous Media, Dover, New York.
Elger, D., and McLam, E.(1990). “Rating of gravity roof ventilator draft,” ASHRAE Trans., 96(2), 356–360.
Fox, W., and McDonald, A. (1992). Introduction to fluid mechanics, Wiley, New York.
Hartman, H., Mutmansky, J., and Wang, Y. (1982). Mine ventilation and air conditioning, Wiley, New York.
Lambe, T., and Whitman, R. (1969). Soil mechanics, Wiley, New York.
Massman, J.(1989). “Applying groundwater flow models in vapor extraction system design.” J. Environ. Eng., 115(1), 129–149.
Morris, C., and Thomson, B. (1996). “Water and vapor transport in a two-layer soil system.” Proc., 3rd International Symposium on Environmental Geotechnology, 282–291.
Pasquil, F., and Smith, F. (1983). Atmospheric diffusion, Wiley, New York.
Prandtl, L. (1967). Essentials of fluid dynamics with applications to hydraulics, aeronautics, meteorology, and other subjects, Blackie, London.
Stormont, J., Ankeny, M., and Kelsey, J.(1998). “Airflow as monitoring technique for landfill liners.” J. Environ. Eng., 124(6), 539–544.
Vogel, S., Ellington, C., and Kilgore, D.(1973). “Wind induced ventilation of the burrow of the prairie-dog-cynomys ludovicianus.” J. Comp. Physiol., 85(1), 1–14.
Welsh, P.(1995). “Free standing ventilation terminals: Testing and rating.” Build. Serv. Eng. Res. Technol., 16(4), 189–198.
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Copyright © 2002 American Society of Civil Engineers.
History
Received: Mar 16, 2001
Accepted: Jul 23, 2001
Published online: Apr 1, 2002
Published in print: Apr 2002
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