How to calculate the circulation around a vortex core.

Problem:

I extracted a vortex core using the Tecplot CFD Analyzer, and now I want to calculate the circulation around the core. How can I do this?

Solution:

If you can define a closed path in your data over which to integrate, you can calculate circulation using the Integrate dialog.

1. Open the dialog by choosing “Perform Integration” from the Analyze menu.
2. In the Integrate dialog that appears, for Type of Integration, select Vector Dotted with Unit Tangential.
3. Choose your velocity components for the Integrand.
4. Next, identify a line–a closed path–as your Domain of Integration. (If you want to read more on specifying the domain of integration, click the Help button and scroll down a bit on the resulting Help Web page.)
5. Finally, click Integrate. The Integration Results dialog will display the circulation.