Page 181 - Process Modelling and Simulation With Finite Element Methods

168 Process Modelling and Simulation with Finite Element Methods

transfer coefficient boundary condition of the Biot type that is easily included in
any pde engine. But with ci integrably coupled to the dynamics in the bounding
domain, the implementation here, made possible by extended multiphysics in
FEMLAJ3, is unique. Attempts by one of us to implement this boundary
condition in other finite element solvers were once abandoned due to the
complexity of the coding.

Reaction/ConvectiodDiffusion Model
If FEMLAB is already launched, select New from the File Menu, which will
bring up the Model Navigator.

Model Navigator
Select 2-D dimension
Select ChemEng Modes-Cartesian Coordinates+Mass
Balance-Convection-Diffusion*Time-Dependent>>
OK

Now use the File menu to “Insert from File” and select your Geometry mat-file
(pellet-geom.mat).

Next select the AddEdit constants options and enter as below.

AddEdit Constants

Name I Expression
D I1
I Keff I1 I
sigma I40
ClO I 1.

Now pull down the Subdomain menu and select Subdomain settings.

Subdomain Mode
Select subdomain 1
Enter PDE coefficients
Set Di=D; Ri=O; u=pelletu(x,y); v=pelletv(x,y)
Select subdomain 2, check inactive in this domain
ApplyJOK