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laws:ptrns

PTRNS

Description

Advection‑diffusion constitutive law in saturated-unsaturated porous media for solid eulerian elements (element TRPO2)
(Pollutant TRansport in Non Saturated conditions)

The model

This law is only used for linear pollutant transport in isotropic solids by upwind methods in saturated-non saturated porous media.
This constitutive law takes into account the advection‑dispersion in the moving fluid but also degradation, adsorption on the solid matrix and immobile fluid effect as linear phenomena. This law is used for two‑dimensional flow.

Files

Prepro: LPTRNS.F

Availability

Plane stress state YES
Plane strain state YES
Axisymmetric state YES
3D state NO
Generalized plane state NO

Input file

Parameters defining the type of constitutive law

Line 1 (2I5, 60A1)
ILLaw number
ITYPE 131
COMMENT Any comment (up to 60 characters) that will be reproduced on the output listing

Integer parameters

Line 1 (3I5)
INDV= 0 constant advection
= 1 space time variation of advection
= 2 only space variation of advection
= 3 semi coupled analysis with flow
INDM= 0 same meshing for flow and pollution
= 1 different meshing
INDS= 0 fully saturated porous media
= 1 saturated-unsaturated porous media
Line 2 - Only if INDS = 1 (9I5)
IFATlaw formulation indexes for the 9 parameters
(respectively $a_T, a_L, D_m, R_{dm}, R_{dim}, A_m, A_{im}, \alpha_m, \alpha_{im}$)
in unsaturated condition:
0 = constant formulation
1 = linear formulation
IFAL
IFDM
IFROM
IFRDIM
IFAM
IFAIM
IFALM
IFALIM

Real parameters

Line 1 (7G10.0)
UABS- constant apparent velocity modulus
TETAconstant apparent velocity direction (angle in RAD)
CIM0initial immobile water concentration
ALALXfirst facultative imposed upwind in X direction
ALALYfirst facultative imposed upwind in Y direction
BEBEXsecond facultative imposed upwind in X direction
BEBEYsecond facultative imposed upwind in Y direction
Line 2 (7G10.0)
ATRANStransversal dispersivity of the porous medium $(a_T)$ in
ALONGlongitudinal dispersivity of the porous medium $(a_L)$ fully
DIFFM molecular diffusion of the porous medium $(D_m)$ saturated
RDMretardation factor for mobile water $(R_{dm})$ conditions
RDIMretardation factor for immobile water $(R_{dim})$
AMdegradation constant for mobile water $(A_{m})$
AIMdegradation constant for immobile water $(A_{im})$
Line 3 (3G10.0)
ALMtransfer constant for mobile water $(\alpha_{m})$
ALIMtransfer constant for immobile water $(\alpha_{im})$
PEFFeffective surface porosity of the porous medium.

Only if INDS = 1:

Line 4 (3G10.0)
CAT11st coefficient of the function $a_T(S_r)$
CAT22nd coefficient of the function $a_T(S_r)$
CAT33rd coefficient of the function $a_T(S_r)$
Line 5 (3G10.0)
CAL11st coefficient of the function $a_L(S_r)$
CAL22nd coefficient of the function $a_L(S_r)$
CAL33rd coefficient of the function $a_L(S_r)$
Line 6 (3G10.0)
CDM11st coefficient of the function $D_m(S_r)$
CDM22nd coefficient of the function $D_m(S_r)$
CDM33rd coefficient of the function $D_m(S_r)$
Line 7 (3G10.0)
CRDM11st coefficient of the function $R_{dm}(S_r)$
CRDM22nd coefficient of the function $R_{dm}(S_r)$
CRDM33rd coefficient of the function $R_{dm}(S_r)$
Line 8 (3G10.0)
CRDIM11st coefficient of the function $R_{dim}(S_r)$
CRDIM22nd coefficient of the function $R_{dim}(S_r)$
CRDIM33rd coefficient of the function $R_{dçm}(S_r)$
Line 9 (3G10.0)
CAM11st coefficient of the function $A_{m}(S_r)$
CAM22nd coefficient of the function $A_{m}(S_r)$
CAM33rd coefficient of the function $A_{m}(S_r)$
Line 10 (3G10.0)
CAIM11st coefficient of the function $A_{im}(S_r)$
CAIM22nd coefficient of the function $A_{im}(S_r)$
CAIM33rd coefficient of the function $A_{im}(S_r)$
Line 11 (3G10.0)
CALM11st coefficient of the function $\alpha_{m}(S_r)$
CALM22nd coefficient of the function $\alpha_{m}(S_r)$
CALM33rd coefficient of the function $\alpha_{m}(S_r)$
Line 12 (3G10.0)
CALIM11st coefficient of the function $\alpha_{im}(S_r)$
CALIM22nd coefficient of the function $\alpha_{im}(S_r)$
CALIM33rd coefficient of the function $\alpha_{im}(S_r)$

Remarks on parameters

  1. Upwind parameters:
    • If ALALX and ALALY $\in \left[0,1\right] \rightarrow$ HUGHES formulation for the first upwind
      BEBEY and BEBEY $\in \left[0,1\right] \rightarrow$ HUGHES formulation for the first upwind
    • If ALALX $\in \left[0,1\right] \rightarrow$ formulation in FRENET axes for the first upwind
    • If BEBEX $\in \left[0,1\right] \rightarrow$ formulation in FRENET axes for the second upwind
    • Otherwise optimum formulation in FRENET axes
  2. Physical parameters:
    • RDM = $1 + \theta_s \rho_s p K_d / \theta_m$
    • RDIM = $1 + \theta_s \rho_s (1-p) K_d / \theta_{im}$
    • AM = $k_s.(RDM -1).+ k_m + ALM$
    • AIM = $k_s.(RDIM -1).+ k_{im} + ALIM$
    • ALM = $\alpha_\alpha/\theta_m$
    • ALIM = $\alpha_\alpha/\theta_{im}$
      With:
      • $\theta_s$ = 1-total porosity
      • $\theta_{m}$ = effective porosity
      • $\theta_{im}$ = non effective porosity
      • $k_{s,m,im}$ = degradation coefficients in solid, moving and non-moving fluids
      • $K_{d}$ = linear adsorption coefficient
      • $p$ = part of solid surface in contact with the moving fluid
      • $\rho_s$ = solid density
      • $\alpha_d$ = exchange coefficient between mobile and immobile fluids

Following empirical formulations for describing the evolution of the transport parameters “P” ($=a_T, a_L$; $D_m, R_{dm}, R_{dim}, A_m, A_{im}, \alpha_m, \alpha_{im}$) with the saturation $S_r$ are possible ($P_{sat}$ = value of the parameter in fully saturated conditions, when $S_r = 1$) :

  • constant formulation : $P(S_r) = P_{sat}$
  • linear formulation : $P(S_r) = P_{sat}\left[ (1-coeff.1).S_r + coeff.1\right] \Rightarrow coeff1 = \frac{P(S_r = 0)}{P_{sat}}$

Stresses

Number of stresses

8

Meaning (numerical, not physical)

SIG(1)pollutant flow in the X direction $(=q_X)$
SIG(2)pollutant flow in the Y direction $(=q_Y)$
SIG(3)pollutant dispersive flux in X direction
SIG(4)pollutant dispersive flux in Y direction
SIG(5)pollutant storage due to time variation of concentration
SIG(6)pollutant storage by convection and not restored by degradation
SIG(7)pollutant flux from moving to non moving fluid
SIG(8)pollutant degradation

State variables

Number of state variables

6

List of state variables

Q(1) fluid Darcy velocity in the X direction
Q(2) fluid Darcy velocity in the Y direction
Q(3) fluid storage
Q(4) immobile water concentration.
Q(5) mobile water concentration (if INDV = 3)
Q(6) saturation degree
laws/ptrns.txt · Last modified: 2020/08/25 15:46 (external edit)