# Numerical Solution — Lesson 6

#### Second Order Upwind Momentum Scheme

Solution > Solution Methods > Spatial Discretization.
Set Momentum to Second Order Upwind

#### Convergence Criterion

Solution > Monitors > Residuals > Edit....
Set the Absolute Criteria for continuityx-velocity and y-velocity to 1e-6. Click ok

Solution > Monitors > Create > Drag

NOTE: In Ansys 18.2, implementing the drag monitor is slightly different. The pictures above do not match exactly with version 18.2. See following video for version 18.2.

Then check Print to Console and Plot. Next, click cylinderwall, which is located under Wall Zones. Lastly, click ok.

#### Initial Guess

Solution > Solution Initialization > Standard Initialization.
Set Compute From to farfield1. Alternatively, you can simply set X Velocity to 1 m/s. Then, click Initialize.

#### Iterate Until Convergence

Solution > Run Calculation.
Set the Number of Iterations to 2000. Then, click Calculate. (You may have to hit Calculate twice.) Now, have a cup of coffee. The solution should converge after approximately 1600 iterations. NOTE: In newer versions of ANSYS, solution may converge in fewer iterations.