2018 BFY III Abstract Detail Page
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||W04: Investigating Hydrodynamic Instabilities Using Table-Top Experiments
||In fluid mechanics, flows are sometimes observed to undergo sudden qualitative changes as a system parameter is varied. These instabilities usually involve the spontaneous breaking of the spatial and temporal symmetries of the flow and the formation of visually appealing vortical structures with complex spatiotemporal dynamics. In this workshop, we will discuss two simple table-top experiments that can be used to study flow instabilities that emerge as flow rates are increased and the smoothing effects of viscosity are overcome by inertia. The first of these, Taylor-Couette flow, is the flow between rotating coaxial cylinders and has long been an important tool in the study of nonlinear dynamics and pattern formation theory. The second experiment is an electromagnetically-driven implementation of Kolmogorov flow, a model system for understanding the effects of shear in quasi-2D flows such as those in the ocean or the atmosphere.
Despite the complex physics that underlies these experiments, they are simple and inexpensive to construct ($200-300) and are therefore ideally suited to teach students about the design and fabrication of scientific apparatus. They can be implemented as a series of instructional modules on basic electronics and electromechanics (stepper motors), computer-aided design (CAD), fabrication methods (soldering, machining, laser cutting, 3D printing, etc.), and scientific image acquisition and processing. The apparatus are quite flexible and can be used to study a host of important topics in fluid mechanics and nonlinear dynamics including bifurcations, flow visualization, Reynolds similarity, the time reversibility of low Reynolds number flows, the coexistence of attractors in nonlinear systems, chaos, and attractor reconstruction from time series.
Participants interested in a more in-depth look at the physics underlying the various experiments and a hands-on tutorial on constructing their own apparatus are encouraged to sign up for the ALPhA Immersion on "Flow Instabilities in Taylor-Couette Flow," which will be held at Willamette University in Salem, Oregon between Aug. 8th and Aug. 10th.
900 State St.
Salem, OR 97301
|Workshop Doc 1:
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|Workshop Doc 2:
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