Abstract: A device including a flow unit generating a potential vortex having an inflow aperture and an outflow aperture, together with a turbine arranged in the direction of flow of the potential vortex. The flow unit comprises an outer hollow member having a plurality of flaps and plates at both ends, with one plate containing the outflow aperture, and an inner hollow member arranged concentrically of the outer hollow member. The built-up pressure acting on the outer hollow member opens some of the movable flaps and closes others, which generates a rotary flow. The rotary flow, while flowing tangentially into the inner hollow member, is accelerated further and forms a swirl flow which is directed outwardly by the vacuum at the outflow aperture and which, after having passed through the outflow aperture, is converted into the potential vortex by the shear forces of the parallel flows.