Growth of Unstable Modes in Stratified Boundary Layer Flow

Undergraduates: Matthew Hurley, Pierre-Yves Passagia

Faculty Advisor: Pierre-Yves Passagia
Department: Physics & Astronomy

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Boundary layer flow over a flat plate is one of the cornerstone problems of fluid mechanics and is vital to the understanding engineering in aquatic and wind susceptible environments. Yet models and experiments focusing on instabilities in stratified boundary layer flow are sparse. In fact, no experiment illustrating the growth of unstable modes in stratified Blasius flow has ever been done. We have constructed both a numerical model and a large scale experiment in the UNC Fluids Lab to compile a comprehensive description of the problem. Using PIV we will compare the results from the experiment to those found in the model and attempt to excite the most unstable modes. The results from this experiment are aimed at designing efficient bladeless wind turbines near ground level. Initial results indicate two unstable, growing modes in the flow which can be agitated using actuators in the experiment.