I am currently working on a device that requires omnidirectional air currents (e.g. breezes/winds) to be directed downwards through a vertical tube. I think it would be a very similar design to a whirlybird, but the air would have to flow inwards rather than outwards.
Could this be achieved by create several curved blades and arranging them in a 360 degree pattern, and then maybe having a second fan in the tube itself? Would one-way valves also be required to ensure that air is flowing into the tube?