That could not have been said better! Devices are key to understanding Flow Controlling dynamics. There are many physics laws (known and unknown) that will astonish you!
Understanding the cutting of said "Impeller" is a whole profession in itself. Berkley Sta right have been doing this foreva. To learn impellers, their unique physics will provide a step up in fluid dynamics as a whole...
Possibly contact someone at those Companies. They may be able to provide...
My background is in fluid dynamics. Controlling high velocity fluids via atmospheric and offset dynamics.
I have put some evidences together, for discussing a new working principle theory. These simple experiments, along with known experiments found on YouTube, come to be a very interesting...