View Erosion with Massed Particle Traces

Setup and run the erosion simulation using standard modeling practices. (There are no steps to perform prior to launching the calculation.)

Create a results plane, and move it to an inlet. Open the Trace dialog.
Select Rectangular grid as the trace seeding method, and check Use grid spacing. (Note that the other seeding methods are also suitable.)
Click Add trace set.
Click Trace list...
Click Mass... near the bottom of the Traces dialog.
On the Mass dialog, click Enable/Update Erosion.

To adjust the Grid spacing density...

Enable vectors on the results plane.
On the Vector settings tab of the Plane Control dialog, drag the Grid spacing slider.

Properties of Sand

These are the properties of sand, the cause of erosion in many systems:

Particle density = 2705 kg/m3
Radius = 0.014 in
Coefficient of restitution = use default value (computed as part of erosion calculation)
Time step size = The time step size is automatically computed to ensure that the particle passes through an element in one time step.

Note: The erosion rate is a function of the number of traces. A higher number causes smoother erosion results and higher erosion rate values. Be careful, however, not to prescribe so many traces as to exceed the graphics memory of your computer. The number of traces to be created is displayed when using the Grid Spacing method. A good limit for most computers is 1000 traces.

Note: The erosion legend units are in terms of mass rate / area. This is based on a particle rate of one particle per unit time at each seed location.

It is a good idea to hide the traces after erosion results are generated. This improves graphical performance significantly, and makes it easier to view erosion on surfaces of the model.

To update the erosion results after modifying any of the parameters on the Mass dialog, click Enable/Update Erosion.

The Erosion Rate result is not available while the simulation is running, and is removed when a simulation is continued. Follow the procedure described above to display erosion after the simulation is stopped.

Comparing Erosion across Multiple Scenarios

To view summary images showing erosion in the Design Review Center, perform the following procedure:

After creating an erosion view, save a Summary Image.
Save a view settings file containing the massed particle traces used to compute erosion. This ensures that the same number of traces is used in each scenario. (This is essential to ensure consistent results.)
Open each scenario, and apply the view settings file. Open the Massed Traces dialog, and click Enable/Update Erosion.
In the Decision Center, update the Summary Image. Use the Design Review Center to compare the results from each enabled scenario.