Abstract : Forced unsteady fluid flows are examined from the point of view of positive implications of the time dependency. Particular problems examined in a forced unsteady mode are jets, wind tunnels, wings, ramps and diffusers, dump combustors and vortex structure. Two methods of forcing the flow are studied in detail, fluidic feedback and a cam-shaped rotor. The fluidic method produces an unsteady jet while the rotor acts as a time dependent vortex generator. Potential performance improvements with unsteady flow are evident in all of the flows examined. (Author)