FLUENT 12.1 - Unsteady Flow Past a Cylinder - Solution

5. Solution

Convergence Criterion: Turn off Drag, Turn on Lift

Solution > Monitors > Drag > Edit.... Then uncheck Print to Console and uncheck Plot. Click ok.

Solution > Monitors > Lift > Edit.... Then check Print to Console, Plot and Write. Click ok. The last option writes the lift coefficient data to a file that is buried in one of the subfolders that FLUENT creates in the working folder. You'll have to dig around to find it.

Solution Initialization

Adapt > Region.... Then set X Min to 0.5 m, set X Max to 32 m, set Y Min to 0 m, and set Y Max to 32m. Click Mark then click Close.

Solution > Solution Initialization. Set Compute From to farfield1.. Click Initialize. Next, click Patch. Complete the patching menu as shown below.



Click Patch,then click close.

Setting Up Data Export to Create Animation

We would like to create an animation of the vorticity magnitude after the solution has been calculated. To do so, we will need to export data from FLUENT to CFD-Post, the post processor used to view results. To do so, go to {_}Solution > Calculation Activities > Execute Commands > Create/Edit. Now, set up the window to appear as the image below. The command entered is 'file export-to-cfd-post unsteady-%t.cdat x-velocity y-velocity velocity-curl q no no'. In this case, we will export the x and y components as well as the curl of the velocity every time step.

Advance Solution in Time

Solution > Run Calculation. Set Time Step Size to 0.2 seconds and set the Number Of Time Steps to 200. Now, click Calculate. (You may have to hit Calculate twice.) Now, have a cup of coffee. Continue the time-stepping until you get sinusoidal variation in the lift coefficient.

Save Project

Go to Step 6: Results

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