Setting up the Models

Models define the primary variables of the simulation, including pressure, temperature, velocity, and what mathematical formulation will be used to generate the solution. In this example, the flow is turbulent and compressible. The Coupled Flow model will be used together with the default k-epsilon turbulence model.

As there are two materials (air and aluminum) present, two regions are required for the analysis. We will need to define two sets of continuum models, each appropriate to a different region. By default, Physics 1and Physics 2 are automatically created when the mesh is imported. We will use these continua for the fluid and the solid.

Right-click on the Physics 1 node and select Rename...

Change the name to Air and then click OK.

Using the same technique, rename the Physics 2 node Aluminum Alloy.

The air continuum should be edited so that appropriate physical models are selected for the air fluid region.

Open the Continua node, right-click on the Air node and select item Select models...

Select the Two Dimensional radio button in the Space group box.

Similarly, select the Stationary radio button in the Motion group box. This action changes the types of group boxes in the dialog.

The Physics Model Selection dialog will guide you through the model selection process by showing only the options appropriate to the initial choices made. Using the same technique as in the previous step:

Select Gas in the Material group box.

Select Coupled Flow in the Flow group box.

Select Ideal Gas in the Equation of State group box.

Select Steady in the Time group box.

Select Turbulent in the Viscous Regime group box.

Select K-Epsilon Turbulence in the Reynolds-Averaged Turbulence group box.

Select Gravity in the Optional Physics Models group box.

The Physics Model Selection dialog should look as shown below when you are done.

Click Close.

In the heatedFin window, open the Continua node.

The color of the Air node has turned from gray to blue to indicate that models have been activated.

Open the Air > Models node. The selected models now appear within that node.

Right-click on the Aluminum Alloy node and select item Select models...

Select Two-Dimensional in the Space group box.

Select Stationary in the Motion group box.

Select Solid in the Material group box.

Select Coupled Solid Energy in the Optional Models group box.

Select Constant Density in the Equation of State group box.

Select Steady in the Time group box.

Click Close.

In the heatedFin window, open the Continua node.

The color of the Aluminum Alloy node has turned from gray to shaded gray to indicate that models have been activated for this continuum.

The selected models for the continuum can be reviewed by opening the Aluminum Alloy and Models nodes.