Hello everyone, I would just like to know these few things, since I'm trying to build my own little variation of a wind tunnel for my experiment with sound. 1. How is the velocity of the wind inside the tunnel measured? 2. Following the first question, how then would I go about manipulating the wind velocity? Assuming I'm using 80mm computer fans. I've been searching around the web for answers, but to no avail. I was hoping someone here could help me out. Thanks in advance.