The Magnus Effect is a feature of airflow around a spinning body that is also moving relative to the airstream (or that has air flowing over it). The spinning flow combines with the one-directional flow to produce a net sideways force that, unless balanced out somehow, will push the body to the side.
See "WhoisAlanGreenspan?" fantastic video primer on the subject.
https://freerepublic.com/focus/chat/4255835/posts?page=100#100
Good video on Flettner rotors but this one doesn’t rotate.
It says clearly in the article that the cylinders don’t spin. It is not based on the Bernoulli (or Magnus) effect . Here it is...
“The CoFlow Jet cylinders developed by Zha DON’T ROTATE. They draw in a bit of the air from the wind blowing across and through them and then expends it at another part of the cylinder.”
And here’s a good video of the Magnus effect.
This is not what they’re talking about. There have been several ship built on the Magnus effect (rotor ships) over the decades. The fact that they haven’t taken hold tells you all you need to know about their practicality.