Experimental techniques for turbulent Taylor–Couette flow and Rayleigh–Bénard convection

Abstract

Taylor-Couette (TC) flow and Rayleigh-Bénard (RB) convection are two systems in hydrodynamics, which have been widely used to investigate the primary instabilities, pattern formation, and transitions from laminar to turbulent flow. These two systems are known to have an elegant mathematical similarity. Both TC and RB flows are closed systems, i.e. the total energy dissipation rate exactly follows from the global energy balances. From an experimental point of view, the inherent simple geometry and symmetry in these two systems permits the construction of high precision experimental setups. These systems allow for quantitative measurements of many different variables, and provide a rich source of data to test theories and numerical simulations. We review the various experimental techniques in these two systems in fully developed turbulent states.

Flow Resistance Modeling for Coolant Distribution within Canned Motor Cooling Loops

“…The expression of the fitting function could be derived through the least squares method and is expressed in Eqs. (15) and (16), indicating the influence of the axial Reynolds number and rotational Reynolds number on the frictional coefficient in axial flow.…”

“…The established prediction models presented in Eqs. (15) and (16) were developed from the experimental results and subjected to certain axial Reynolds numbers. A total of four sets of simulations were carried out with a wider range of Re a values as shown in Figure 12.…”

“…The dashed lines in the picture denote the results calculated with the empirical prediction model as expressed in Eqs. (15) and (16), and the lines with differently shaped points represent the simulated results from the Fluent software.…”

“…Yew's study demonstrated that the flow resistance caused by rotation could be significant, and concluded that the friction factor of laminar flow was not affected by rotation. Sun Chao summarized measuring techniques for turbulent Taylor-Couette flow and provided an experimental point of view on high precision experimental setups [15]. However, the experiments in the review had no axial flow, which indicated that the TCP flow measurements were far from comprehensive and mature.…”

Work-in-Progress: Visualization and Simulation of the Thermal Boundary Layer around a Cylinder as a Classroom Demonstration

“…Hence, refracted light rays cast a shadow with varying light intensity to produce the shadowgraph. After passing through the fluid, the light beam may be projected onto a screen or can be refocused by another lens or mirror and recorded by a CCD camera [12,13].…”