What is Grading in butterfly?


As I am simulating indoor airflow with butterfly, I am trying to make sense of most of butterfly’s components for myself, and I can’t seem to get a clear idea of wind tunnel grading, what does it do? and what how do you adjust it with “grade xyz”?

I’d appreciate it if someone could enlighten me!

Look for grading in this page:

This page might also be helpful:

Hi,@alexjiangarc wind tunnel grading is for the outdoor wind simulation, not for the indoor airflow.