Abstract: A fluid flow device is described. A rotor of the fluid flow device has one or more bubbles such as open-ended scoop cups in a rotor disc. The rotor is located in a shroud. In the case of a compressor, the rotor is driven by power and upon rotation, scooping action of the scoop cups generate fluid flow through the rotor. In a power plant configuration, high speed fluid flow drives the rotor and the power is generated on its shaft. In another embodiment, a stator is also provided in the shroud. The stator also has one or more inlet cups and outlet cups to produce desired fluid flows through the stator. In further embodiments, multi-stage fluid flow devices are described in which one or more rotors and stators are alternately located in the shroud which is substantially axially symmetrical.