Page History

...

Now that we're done with Boundary Conditions, we're almost ready to run the simulation!

Solution Methods

Here we will specify various settings of the method used to solve. Each option change the order or accuracy of the calculation of each possible variable. On simple problems the default setting usually work pretty well. But once you start to make you own simulations of more complex problems, you soon will understand the importance of selecting the correct method here.

For this problem, just change the first option, "Scheme" to "Coupled". Leave the rest as default.

FIGURE 18

Monitors

Here is where we define parameters to help checking for convergence. Residuals, the first one already embedded, is a measure of the linearization error. We define some threshold value and when the Residuals are below that value, the solution has converged.

The smaller the Residual criteria, less error is expected, however considerable more simulation time will be require.

Since this is a simple problem, we can set the Residuals to be smaller than the 0.001 default value. For that, highlight the first line in the first "Monitors" box, "Residuals - Print, Plot", then click "Edit...".

The right most box containing the 0.001 number is the threshold we just discussed. There are 5 of them, continuity, x-velocity, y-velocity, k and epsilon (you might have to scroll down to see the last one). Change all values to "1e-6". (Note, "Ctrl C" does not work here...). Click Ok.

FIGURE 19

Now, let's create a monitor for Moment.

Click "Create > Moment...".

FIGURE 20

Under "Options", check the boxes to "Print to Console" and "Plot". Under "Wall Zones", select "wall_blade_right". Change the "Moment Center" to X=0.04m and Y=0. Click Ok.

FIGURE 21

Similarly, create a similar monitor for "wall_blade_top". Remember to change the Moment Center to X=-0.02m and Y=0.034641m.

Initialize the solution and run the calculation.

Highlight "Solution Initialization". Keep the "Hybrid Initialization" selected and click Initialize.

Highlight  "Run Calculation". Change the Number of Iterations to about 400 and click Calculate.

MAYBE it's to big? Video...? 

...