Operator DARCYSAT DATE 98/10/09 Procédure DARCYSAT ------------------ See also :PECHE DARCYTRA TAB1 ; TAB1.'SOUSTYPE'.'MODELE'.'DOMAINE'. 'ALPHA','BHETA','NEXP','MEXP','TERESIDU','PORO', 'PERMSAT','METHODE', 'TEMPS'.'TRACE_CHARGE'.'CHARGE'.'FLUX'. 'BLOCAGE'.'CHARGE_IMPOSE'.'FLUX_IMPOSE'.'SOURCE'. 'TEMPS_FINAL','NPAS','NITER','ITMAX','PREC' 'THETA'.'CFL','DELTAT0' Description : _____________ This procedure enables to excute a transient calculus for unsaturated media a mixed finite element method in space (EFMH), finite differences in time is used. In any case, unknowns field's are head (H), head's trace (TH) and degree of saturation. Contents : __________ On input, TAB1 is used to define the options and the calculation parameters. The indices of the table TAB1 are words (written in words). Here is their list : ___________________________________________________________________ | | | Indice Contenu | | | ------------------------------------------------------------------- | | |------------------------------------------------ | |Données physiques, géométriques et materielles : | |------------------------------------------------ | | | |'SOUSTYPE' 'DARCY_TRANSITOIRE' (type MOT) | | | |'MODELE' Modeled structure for the DARCY formulation | | (MMODEL create by MODE) | | | |'DOMAINE' Geometric references (TABLE create by DOMA) | | | | | |'ALPHA' coefficient de la loi relative a la intrinsic | | permeability reel | | | |'BHETA' coefficient de la loi relative a la degree of | | saturation reel | | | |'NEXP' exponent for a law of the degree of saturation | | reel | | | |'MEXP' exponent for a law of the degree of saturation | | reel | | | |'TERESIDU' teneur en eau residuelle | | reel | | | |'PORO' porosity | | reel | | | |'PERMSAT' permeabilite a saturation | | | |---------------------- | |Conditions initiales : | |---------------------- | | | |'TEMPS' TABLE which contains initial time at the 0 index | | (FLOTTANT) | | | |'TRACE_CHARGE' TABLE which contains initial head's trace at the | | 0 index (CHAMPOIN) | | | |'CHARGE' TABLE which contains initial head at the 0 index | | (CHAMPOIN) | | | |'FLUX' TABLE which contains initial flux at the 0 index | | (CHAMPOIN) | | | |-------------------------------------- | |Conditions aux limites / chargements : | |-------------------------------------- | | | |'BLOCAGE' Contains the RIGIDITE stiffness associated with | | conditions of head's trace values imposed. | | (Optional index) | | | |'TRACE_IMPOSE' Head's trace values imposed. | | (CHARGEMENT - Binding if BLOCAGE index exist) | | | |'FLUX_IMPOSE' Flux's values imposed | | (CHARGEMENT - default 0.) | | | |'SOURCE' Volumetric flow | | (CHARGEMENT - default 0.) | | | |-----------------------------------------------------------------| |Methode de calcul des CAPACITE et PERMEABILITE EFFECTIVE | |-----------------------------------------------------------------| | | |'METHODE' Contient un naturel (0,1 ou 2) | | | | 1 : C et K calculés par moyenne arithmetique des | | valeurs au face | | bonne fiabilité , précision satisfaisante | | | | 2 : C et K calculés avec la pression moyenne élém. | | fiabilité réduite , bonne précision | | | | 3 : C et K calculés par moyenne harmonique des | | valeurs au face | | fiabilité réduite , bonne précision | | | |--------------------- | |Algorithme en temps : | |--------------------- | | | |'TEMPS_FINAL' temps final | | | | | |'NPAS' nombre de pas de temps par defaut 1000 | | | |'NITER' used for the time steps calculus | | (taux de variation du pas de temps) par defaut 10 | | | |'ITMAX' nombre d'iterations maximal | | par defaut 40 | | | |'PREC' precision pour la convergence des iterations | | par defaut 1.d-4 | | | |'CFL' critere de courant used for calculation of the time | | step default 1. | | | |'DELTAT0' value for time step .if this indice is | | time step is automatically calculated | | | | | |'THETA' Relaxation coefficient for the diffusive fluxes. | | Value between 0. and 1. (theta-method) | | (FLOTTANT - default 1.) | | Unstability can appear if theta<1/2. Here is the | | list of current theta's scheme : | | Euler's explicit scheme : 0. | | Crank-Nicholson's scheme : 1/2 | | Euler's implicit scheme : 1. | | | |_________________________________________________________________| On output, TAB1 enables the user to find again the results which are stored in tables whose indices are intergers (0 1 2 .... N) corresponding to the number of the results saving. 0 define the initial time. ___________________________________________________________________ | | | Indice Contenu | | | ------------------------------------------------------------------- | | |'TEMPS' TABLE which contains recorded times (FLOTTANT) | | | |'TRACE_CHARGE' TABLE which contains head's trace (CHAMPOIN) | | | |'CHARGE' TABLE which contains recorded head (CHAMPOIN) | | | |'FLUX' TABLE which contains recoded flux (CHAMPOIN) | | | |'CAPACITE' TABLE which contains pacite hydraulique (CHAMPOIN)| | | |'PERMEFFE' TABLE which contains intrisic permeability(CHAMPOIN)| | | |'TH2O' TABLE which contains (CHAMPOIN)| | | |'PRESSION' TABLE which contains pressure (CHAMPOIN)| |_________________________________________________________________| procedur stops if final times is reached or if all times steps was calculated intrinsic permeability has a the following law: Se ** alfa degree of saturation Se has the following law (1 + (beta*p)**nexp)**(-mexp) with p pressure Example : in order to list the CHPOINT of head calculated for the value of the evolution parameter 2.5, the following will have to be coded : LIST ( PECHE TAB1 'CHARGE' 2.5 ) ; or if we know that the index i of the saved time table TEMPS contains 2.5, we can cod : LIST ( TAB1 . 'CHARGE' . i ) ; TRACHIS and TRACHIT procedures enable to obtain profils or evolutions Remarks : _________ Since the results are located in TAB1, no named objects are created by this procedure. Once you have left DARCYSAT you may re-enter it by defining new values for TEMPS_FINAL or NPAS and by calling once again DARCYSAT with the same operands as the first call.