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dc.contributor.advisorYeh, Tian-Chyi Jimen
dc.contributor.authorBao, Xuezhong
dc.creatorBao, Xuezhongen
dc.date.accessioned2018-02-28T19:47:46Z
dc.date.available2018-02-28T19:47:46Z
dc.date.issued1995
dc.identifier.urihttp://hdl.handle.net/10150/626921
dc.description.abstractRichards' equation is difficult to solve numerically because water flow in the unsaturated zone is complicated by the fact that the soil's permeability depends on its water saturation. The accuracy and computational efficiency of numerical solution are affected by the form of the governing equation, the estimation of the internodal hydraulic conductivity and the time-stepping scheme. In order to save computational time and improve efficiency of numerical techniques, two classical dimensionless numbers, Peclet and Courant numbers, and their combinations, Fourier and Advective Peclet numbers, are used as the criteria for estimating the spatial and temporal increments needed for the numerical solution of the linear Richards' equation (for example expo_nential hydraulic functions) and two new dimensi_onless numbers, Modified Peclet and Courant numbers for the non-linear Richards' equation (van Genuchten's hydraulic functions). In this way, we can get numerical solutions of Richards' equation not only with no oscillation and mass conservation, but also with adequate convergency speed and accuracy. These numbers are only related to the soil-hydraulic properties and grid size.
dc.language.isoen_USen
dc.publisherThe University of Arizona.en
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en
dc.titleMesh design for numerical solution of Richards' Equationen_US
dc.typetexten
dc.typeThesis-Reproduction (electronic)en
thesis.degree.grantorUniversity of Arizonaen
thesis.degree.levelmastersen
dc.contributor.committeememberYeh, Tian-Chyi Jimen
thesis.degree.disciplineGraduate Collegeen
thesis.degree.disciplineHydrology and Water Resourcesen
thesis.degree.nameM.S.en
dc.description.noteDigitized from paper copies provided by the Department of Hydrology & Atmospheric Sciences.en
refterms.dateFOA2018-06-19T04:18:05Z
html.description.abstractRichards' equation is difficult to solve numerically because water flow in the unsaturated zone is complicated by the fact that the soil's permeability depends on its water saturation. The accuracy and computational efficiency of numerical solution are affected by the form of the governing equation, the estimation of the internodal hydraulic conductivity and the time-stepping scheme. In order to save computational time and improve efficiency of numerical techniques, two classical dimensionless numbers, Peclet and Courant numbers, and their combinations, Fourier and Advective Peclet numbers, are used as the criteria for estimating the spatial and temporal increments needed for the numerical solution of the linear Richards' equation (for example expo_nential hydraulic functions) and two new dimensi_onless numbers, Modified Peclet and Courant numbers for the non-linear Richards' equation (van Genuchten's hydraulic functions). In this way, we can get numerical solutions of Richards' equation not only with no oscillation and mass conservation, but also with adequate convergency speed and accuracy. These numbers are only related to the soil-hydraulic properties and grid size.


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