"...But, what I think is as some have mentioned and something that Klaus Rauber told me in 2001 we must consider the very name: Repulsin or Re-pulsin. We have a Repuls i. e. a standing wave between the outer peripheri and the centre. Maybe the frequency can be calculated by looking on the waves of the double membrane. Anyway this is why I think that the speed of sound is interesting. In this speed we have rather instable conditions with lots of noice and pressure "bumps". The chance is high that some frequency is the correct to generate a standing wave between the centre and the peripheri. This means that we will have a pressure node at the centre and one at the opening (like a Kuntz tube). As the waved double membrane by it's rotation and geometry works together with the sound wave the air will start to flow. When the air passes over the tops it will roll over and shape into tourus (donut) rings. Or like smoke rings that lies on the membrane. For each wave the smoke ring will be more twisted together and the rotation increase tremendously. When the air in super fast rotation smoke rings comes out at the peripheri they will flow off succing the air on the outside with them. This, together with the inflow will generate a sub pressure above the device and it will start to move into that sub pressure...."