Page History

...

In the Outline window, select Solution Controls to open the Solution Controls window. Ensure that the Courant Number is set to 5.0.

The Courant Number defines how stable the solution is. For the density based, implicit solver as in this tutorial, the Courant Number could be reduced if there is difficulty in obtaining convergence for the solutionnumber is essentially a non dimensionalized timestep. The flow is approximated to be changing with time and once the changes in the flow are very small, the solver displays a solution. The Courant Number is basically how many steps the solver takes to get to the stable solution. The larger it is, the faster the solution will converge but it will not be very stable and can diverge. The smaller it is, the slower it is but the solution is much more stable. 

Monitors

In the Outline window, click Monitors to open the Monitors window. In the Monitors window, select Residuals - Print,Plot and press Edit.... This will open the Residual Monitors window. We want to change the convergence criteria for our solution. Under Equation and to the right of Continuity, change the Absolute Criteria to 1e-6. Repeat for x-velocity, y-velocity, and energy, then press OK.

...