ON THE HYDRODYNAMIC-DESIGN OF ACTIVE PANELS OF MARINE VEHICLES

The problem of active, or driven, panel motions of marine vehicles alt ering the turbulent boundary layer properties is discussed. The cohere nt (vorticular) structures in a turbulent boundary layer can be altere d by the motions of a panel, causing those structures to grow more rap idly and, as a result, become prematurely unstable and burst. In addit ion, the motions of the panel can produce vortices that interact with those that are naturally produced, and change the character of the bou ndary layer. The motions of the antinodes of the panel can also increa se or decrease the surface shear stress, if the panel is, respectively above ol below its mean position. The cumulative effect of the active -panel motions, then, could be to increase the boundary layer drag. An outline of the analysis of this phenomenon is presented.