In this system there is the water inflow in central area and radial output. The rotation produce centrifugal force and water inside of the rotor is moving in radial direction.
So, this device is simple way to organize asymmetrical vortex: axial inflow and radial outflow of liquid. Reactive force in this system is radial only and by this way the trust can be created in axial direction.
Some additional details: the output flow can be directed in tangential way to accelerate the rotor.
Other Shauberger's project is two rotating disks where gradient of pressure between disks are created. There is water between disks and relative motion of water is created with different velocity for upper disk and for lower disk. The velocity is depend of disk surface topology: molecular rotation of water (micro vortex) are reason for different velocity. Physical sense of the effect is the pressure gradient that was described in my paper.