Page 85 - Process Modelling and Simulation With Finite Element Methods

72 Process Modelling and Simulation with Finite Element Methods

Suitable scalings for time and position,
kR x =yL
Z=t (2.14)
36.11 PML2

substituted into (2.9) yields this simple form of the equation:

(2.15)

Now, let’s consider conduction across a stagnant C02 gas layer of length L
where horizontal boundaries are held constant at 400°C and 500°C.

Start up FEMLAB and enter the Model Navigator:

Model Navigator
Select 1-D dimension
Select Classical PDEs + Heat Equation
Element: Lagrange - quadratic
More >>
0
0 OK
This application mode gives us one dependent variable u, but in a 1-D space
with coordinate x. Now we are in a position to set up our domain. Pull down the
Draw menu and select Specify Geometry.

Draw Mode
Name: interval
start: 0
stop: 1
Apply
0 OK
Now for the boundary conditions. Pull down the Boundary menu and select
Boundary Settings.

Boundary Mode
Select domain 1
Check Dirichlet and h=l; r=500 (T=500)
Select domain 2
Select Dirichlet and h=l; r=400 (T=400)
Apply/OK