[wingineer]

I think the bladeless vortex concept makes no sense. Here's why:

1. The surface area of the machine is small. Think of this as the area that can capture power from the wind. Due to the cylindrical shape this is way smaller than the rotor area of a HAWT or even a VAWT.

2. Vortex induced vibration [1] is a real phenomenon that can extract energy from a flow. However, to extract this energy, the natural frequency of the structure must synchronize with the vortex shedding frequency of the flow around the structure. This is called "lock-in". Since the wind is a highly variable resource, it will not consistently be in this "lock-in" range in real-world conditions. To give perspective on the norm for HAWTs, pitch control for the blades is used along with generator torque control to achieve power production from 3 m/s all the way to the maximum (cut-out) wind speed of ~25 m/s.

[1]https://en.wikipedia.org/wiki/Vortex-induced_vibration

[fho]

I guess you can "tune" the tower by adjusting a weight in the tower ... but I agree on the area issue.