Index

Porous medium and fluid viscosity

Ver: 0
 
 

DESCRIPTION

Flow of fluid through porous media obeys Darcy's law ; material data must be specified for both the solid (porous media) and the fluid. Entering this menu allows the user to specify material data for the porous media and a reference viscosity for the fluid.
The structure of the porous media may be non-isotropic;  in this case,  tensor data must be entered  (posistive-definite).

All entries receive a default value.

  OPTIONS
 
-1 Upper level menu
The user accepts the current setup
1' Switch to tensor mode
By default, the prorous media has an isotropic structure. This option must be selected if the porous media has a non-isotropic structure.
Note that the permeability tensor must be positive definite
1" Switch to scalar mode
This option must be selected if the porous media has an isotropic structure
According to the selection in option 1, we have   in scalar mode :
2 Modification of permeability
The permeability must be strictly posotive.
By default, permeability = 1
3 Modification of fluid viscosity
For non-isothermal flows, the value of the viscosity must be specified for a reference temperature.
By default, viscosity = 1
4 Modification of void fraction
By default, void fraction = 0
5  Modification of solid conductivity
Available only for non-isothermal flows.
By default, solid conductivity = 1
6 Modification of solid heat capacity
Available only for non-isothermal flows.
By default, solid heat capacity = 0
7 Modification of solid density
Available only for non-isothermal flows.
By default, solid density = 0
  in tensor mode :
2  Modification of fluid viscosity
For non-isothermal flows, the value of the viscosity must be specified for a reference temperature.
By default, viscosity = 1
3 Modification of Pxx
Pxx is the permeability coefficient in the x-direction for a small surface element, the normal of which is in the x-direction.
By default, Pxx = 1
5 Modification of Pxy
Pxy is the permeability coefficient in the y-direction for a small surface element, the normal of which is in the x-direction.
By default, Pxy = 1
... The permeability tensor has 3 and 6 components for 2-D and 3-D flows, respectively
6(9)  Modification of void fraction
By default, void fraction = 0
7(10) Modification of solid conductivity
Available only for non-isothermal flows.
By default, solid conductivity = 1
8(11) Modification of solid heat capacity
Available only for non-isothermal flows.
By default, solid heat capacity = 0
9(12)  Modification of solid density
Available only for non-isothermal flows.
By default, solid density = 0
NOTES Convergence in one step for non-isothermal flow problems can not be guaranteed; in case the program diverges, an evolution scheme should be considered.


SEE ALSO