It's significant that high-solidity turbines with many blades are in use. As you say, they're quite common in small-scale settings like water pumping. An arti

It's significant that high-solidity turbines with many blades are in use. As you say, they're quite common in small-scale settings like water pumping. An article purporting to 'discover' that design would probably be more shocking if it wasn't already in common use for sensible applications.