So far, so good. It is now time to add diffusion. As before, we begin with creating a compartment model.

Editing the model structure

1. Open the first model. Smile.
2. Connect Layer_1 and Layer_2 with a Transfer block. Name the block “Diffusion_1_2”.
3. Connect Layer_2 and Layer_1 with a Transfer block. Name the block “Diffusion_2_1”.
4. Connect Layer_2 and Layer_3 with a Transfer block. Name the block “Diffusion_2_3”.
5. Connect Layer_3 and Layer_2 with a Transfer block. Name the block “Diffusion_3_2”.
6. Connect Layer_3 and Out with a Transfer block. Name the block “Diffusion_3_Out”.

Assigning values

1. Edit Diffusion_1_2. Assign the expression “D/(R * dx²)” where:

   
   

   Name	Type	Unit	Full Name	Value/Expression
   D	Parameter	m2 year-1	Diffusion coefficient	1

   
   

2. Assign the same expression to all the diffusion Transfer blocks.

3. Run a simulation and make a plot of Flux_Out. What has happened to the curve?

4. Save the project.

Solution to this part

• solution_transport_3.eco

Next

• Adding Diffusion to the Transport Model (5/5)

Previous

• Creating a Transport model

References

• Back to Tutorials
• Home