Courses: The GoldSim Contaminant Transport Module:

Unit 5 - Building a Simple Model of a Well-Mixed Environmental Compartment

Lesson 3 - Understanding the Material Container

Starting in this Lesson, we are going to build the model described in the previous Lesson.  If GoldSim is not already open, open it now. 

If GoldSim is already open, let’s make sure we start with a new model. From the main menu. Press File | New.  If the model that was previously open had been edited at all, GoldSim will ask if you want to save the model before opening a new model. 

In both cases (whether you closed an existing model, or simply opened GoldSim), you will now be viewing a new model (named Untitled).  Let’s save the model to the “MyModels” subfolder in the “Contaminant Transport Course” folder on your Desktop. You can name it Material.gsm.

Now look at the graphics pane (the right side of the screen).  You should see a Container labeled “Material”: 

If you do, this means that either the CT Module or the RT Module is activated. If one of these modules is activated, the Material Container will always appear when you open a new model.

If you don’t see it, it means that it is not activated. If you don’t see the Material Container, activate the module now by following these steps:

  1. Select Model | Options… from the main menu.
  2. In the dialog that is displayed, select the Modules tab.
  3. In that tab, you will see an entry for either Contaminant Transport or Radionuclide Transport.
  4. Check the box next to that entry.
  5. Next, press the Set as Default button in the dialog.
  6. Press OK to close the dialog. 

After doing so, you will note that the Material Container appears.

Enter the Material Container now.  As you will see, in a new model, the Material Container contains two elements: the Species element and the Reference Fluid element (named “Water” by default):

This Container is actually created merely as a convenient way to organize these (and well as other Fluids and Solids you may create). As such, there is nothing special about this specific Container. If you wanted to, you could move these elements out of the Material Container to some other location, and you could then delete the Container itself. However, you cannot delete either the Species or Reference Fluid element.

Note: Although it is not uncommon to move the Material Container to a different location (i.e., inside another Container), in most cases it is recommended that you use this Container to store your Species, Fluids and Solids.  Doing so makes it easier for others to understand your models.

The Species element and the Reference Fluid (and other Fluids and Solids that you may add to a model) can be thought of as highly specialized Data elements that are used to define the basic physical and chemical properties of the materials in the system.

Before we discuss the contents of the Material Container, move back up to the top of the model, and create a new Container named Inputs.  Go inside this Container and create Data elements for the following inputs:

Variable Value
Volume of Water in Tank 5 m3
Mass of Sand in Tank 0.1 kg
Half-Life of Y 50 day
Density of Sand 1600 kg/m3

When you are done, the Inputs Container should look something like this:

Note that we have intentionally omitted several of the inputs introduced in the previous Lesson from this list (the mass of X and Y initially in the tank, as well as the partition coefficients). Before we can define these we need to create our species, which we will do in the next Lesson.