To let one spin around the other, we screwed the threaded cap just a few Metal spheres.) The French press comes with the central rod and the bottom metal part Objects with a density higher than that of the silicone oil could be used in place of the Prevent the movement of the spheres inside the cylinder we wrapped them with paper. We added some metal spheres (about 1 cm in diameter) to the inside of the cylinder. To avoid buoyancy forces that lift the empty cylinder when immersed in the fluid, Larger than the friction between the external surface of the cylinder and the viscousįluid). Locks onto the shaft (the friction between the metal thread and the plastic hole should be The center of the cap and cylinder are slightly smaller than the diameter of the threaded Printed cap and the 3D printed cylinder onto the metal rod. Shaft, and the bottom metal part provides the pivot around which the shaft spins. 15 The borosilicate glass (Pyrex) beaker of the French press actsĪs the transparent external cylinder of the Taylor-Couette device, while the plunger actsĪs the base for the rotating inner cylinder-the central metal rod is used as the rotating Preparation of coffee and tea) and two 3D printed parts. To assemble our Taylor-Couette apparatus, we used a commercial French press (for the Leaving residues that make the fluid progressively dirtier. Moreover, unless all of the fluid isĭisposed of every time, the colored blobs need to be removed with a syringe or a spoon, Silicone oil, which are not very pleasant to handle. After theĭemonstration, all the tools must be cleaned of fluids such as glycerol, corn syrup, or Mixed with some of the viscous fluid and then carefully injected in the apparatus. Before the demonstration, the colored dyes need to be In practice, however, this standard demonstration requires significant timeĪnd effort to prepare and clean up. III A, we describe how to assemble such an apparatus for Relatively simple Taylor-Couette apparatus to demonstrate the generation of Taylor vortices Proposed online (which, for example, use two drinking glasses) leave much to be desired. However, a replica of the apparatus from the University of New Mexico is available 13 for $550. No commercial scientific instrument suppliers offer a Taylor-Couette apparatus for purchase Unfortunately,ĭespite its apparent simplicity, it is not easy for a novice to establish the demonstration. The reversibility demonstration introduced by Taylor is clear and striking. Surprises both expert and non-expert audiences alike. Seems to go against a common sense understanding of how fluid flow behaves and usually Original blob (except for a small amount of blur caused by diffusion). By spinning theĬylinder the same number of times in the counterclockwise direction, one recovers the After the inner cylinder is spun clockwise four times and the coloredīlob seems to be mixed with the rest of the fluid, a surprise awaits. The demonstration starts with Taylor introducing a blob of dyed The simplicity of this flow, its rich dynamics,Īnd its easy experimental realization made it a popular tool for fluid dynamicists to studyīoth laminar and turbulent flows (for a historical overview, see Ref. The apparatus-named in honor of Taylor, who used it to visualize the famousĬouette, who used it as a viscometer in the thesis 6 he defended in 1890-confines the fluid between two concentricĬylinders with the inner cylinder rotating. 1(a)) filled with glycerol possessing kinematic viscosity about 1100 times that of Uses what is now called a Taylor-Couette apparatus (see Fig. Interest even among lay persons, 4 Taylor National Committee for Fluid Mechanics Films in the 1960s. A classic demonstration of this phenomenon was introduced by Taylor in an instructionalįlows, part of the series 3 produced by the
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