# Solving Physics Problems on Linux

in

In this case, you can see that the meshing created 7,862 nodes and 34,195 volume elements. If this isn't fine enough to handle the accuracy you need, you can click the View→Cad model menu item to bring up the geometry viewer again and then click Model→Preferences. If you do make any changes, don't forget to click Mesh→Remesh to redo the meshing process. This may take some time if you are adding a significant number of subsections.

Now that the object is loaded, let's start setting some initial conditions. For this example, you want to set the temperature on the inside surfaces of the three holes. You can select surfaces by double-clicking on them. If you need to select multiple surfaces, simply hold the Ctrl key down at the same time.

Since you want to treat these three surfaces as a single unit, you'll need to unify them. You can do this by clicking the Mesh→Unify surface menu item. To set initial conditions for the entire problem, click the Model→Setup menu item.

Figure 5. The model setup window allows you to set initial conditions for the entire model as a whole.

Here you can set input and output locations, constants, numbers of iterations or time step procedures, among many other options. You also need to add the equations that will define the physical processes you actually are trying to solve for.

Clicking Model→Equation→Add opens an editing window to create a new equation.

Figure 6. You can add equations to define the physical processes you are trying to model.

In this case, let's just add a heat equation to calculate how heat flows through this pump part. Since you need to apply this to the entire object, you can click the apply box for Body 1 here in the equation editor. But, what kind of object is this? Clicking Model→Material pops up a window where you can define all the physical properties of the object.

Figure 7. You can set all of the physical properties of the materials used within your object.

There also is a button called Material library that allows you to select from a set of predefined materials. In this case, let's set the object to be aluminum. As with the equation editor, you can apply the material type to the object directly here.

Clicking Model→Body Force pops up a window where you can enter values that would represent the right-hand side of the equations.

Figure 8. You can set body forces that define forcing values for the equations being used.

Clicking the Model→Boundary Condition menu item will pop up a new window where you can set boundary conditions for your equations.

______________________

Joey Bernard has a background in both physics and computer science. This serves him well in his day job as a computational research consultant at the University of New Brunswick. He also teaches computational physics and parallel programming.