Costis, Christopher E.2017-01-302017-01-301982http://hdl.handle.net/10919/74471A study on the behaviour of wave-packets and random disturbances, introduced by the vibrating-ribbon technique in a Blasius boundary layer, is presented. The experiments were conducted in the VPI & SU low turbulence wind tunnel. The flat plate model was constructed from an aluminum-paper honeycomb laminate and an aluminum leading edge with an elliptical profile. A theoretical model was developed to verify the random and step-function-form motion of the vibrating ribbon. In the case of random disturbance introduction it was found that the random disturbances behave like infinite number, single-frequency waves and measurements of their growth made possible to verify regions of the neutral-stability curve. In the case of wave-packet creation it was found that the wave packets behave like a structure that consists of waves of certain frequencies that grow or decay not necessarily according to the stability curve but in that way as to maintain the wave-packet structure. Their growth as they move downstream and their quick destruction into turbulence was compared to previously published data.iv, 108, [1] leavesapplication/pdfen-USIn CopyrightLD5655.V855 1982.C677Transition flowTurbulent boundary layerWave mechanicsThesis