THE COURANT AND PECLET NUMBER CRITERIA FOR THE NUMERICAL-SOLUTION OF THE RICHARDS EQUATION

被引:33
作者
ELKADI, AI [1 ]
LING, G [1 ]
机构
[1] UNIV HAWAII MANOA,WATER RESOURCES RES CTR,HONOLULU,HI 96822
关键词
D O I
10.1029/93WR00929
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Recent studies indicate that inaccuracies exist in the numerical solutions of the Richards equation. A need exists to examine such inaccuracies and to correlate them, formally, to the soil hydraulic properties and the size of the spatial and temporal mesh. In the absence of criteria for mesh design, mass conservation and the rate of convergence are usually used as bases for acceptance of the solution. It is well documented, however, that neither can guarantee an accurate solution. This paper proposes the Courant and Peclet numbers as criteria for estimating spatial and temporal increments. The study defines upper limits of these numbers for acceptable accuracy of the numerical solutions. For cases that are characterized by decreasing pressure head gradients, although the initial size of the time step may be extremely small, efficient solutions are possible through a careful choice of an expansion factor for such a step.
引用
收藏
页码:3485 / 3494
页数:10
相关论文
共 36 条
[1]   THE RELATIVE IMPORTANCE OF COMPRESSIBILITY AND PARTIAL SATURATION IN UNCONFINED GROUNDWATER-FLOW [J].
BRUTSAERT, W ;
ELKADI, AI .
WATER RESOURCES RESEARCH, 1984, 20 (03) :400-408
[2]  
Carslaw H. S., 1986, CONDUCTION HEAT SOLI
[3]   A GENERAL MASS-CONSERVATIVE NUMERICAL-SOLUTION FOR THE UNSATURATED FLOW EQUATION [J].
CELIA, MA ;
BOULOUTAS, ET ;
ZARBA, RL .
WATER RESOURCES RESEARCH, 1990, 26 (07) :1483-1496
[4]   ORTHOGONAL COLLOCATION AND ALTERNATING-DIRECTION PROCEDURES FOR UNSATURATED FLOW PROBLEMS [J].
CELIA, MA ;
AHUJA, LR ;
PINDER, GF .
ADVANCES IN WATER RESOURCES, 1987, 10 (04) :178-187
[5]   SOME NEW PROCEDURES FOR NUMERICAL-SOLUTION OF VARIABLY SATURATED FLOW PROBLEMS [J].
COOLEY, RL .
WATER RESOURCES RESEARCH, 1983, 19 (05) :1271-1285
[6]   COMPARATIVE ERROR ANALYSIS IN FINITE-ELEMENT FORMULATIONS OF THE ADVECTION-DISPERSION EQUATION [J].
DAUS, AD ;
FRIND, EO ;
SUDICKY, EA .
ADVANCES IN WATER RESOURCES, 1985, 8 (02) :86-95
[7]  
ELNAWAWY OA, 1990, WATER RESOUR RES, V26, P2705
[8]   MOVING FINITE-ELEMENT MODEL FOR ONE-DIMENSIONAL INFILTRATION IN UNSATURATED SOIL [J].
GOTTARDI, G ;
VENUTELLI, M .
WATER RESOURCES RESEARCH, 1992, 28 (12) :3259-3267
[9]   Studies on soil physics Part I - The flow of air and water through soils [J].
Green, WH ;
Ampt, GA .
JOURNAL OF AGRICULTURAL SCIENCE, 1911, 4 :1-24
[10]   COMPARISON OF NUMERICAL-SIMULATION MODELS FOR ONE-DIMENSIONAL INFILTRATION [J].
HAVERKAMP, R ;
VAUCLIN, M ;
TOUMA, J ;
WIERENGA, PJ ;
VACHAUD, G .
SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, 1977, 41 (02) :285-294