Free Surface Flow in Vertical Taylor-Couette System

Abstract

Vertical Taylor-Couette flow with a free surface at its top has been examined by numerical and experimental approaches. Being compared with the ideal case with infinite length cylinders, this system has effects of the finite lengths, the gravitational acceleration and the surface tension. The inner cylinder rotates and the outer cylinder and the bottom wall are stationary. The numerical approach uses the VOF method to model the free surface. In the experiment, the flow patterns are observed from the top and the meridional views, and the displacement of the free surface is measured. The flow modes are classified by the number of vortices appearing in the meridional plane and the radial flow directions at the top and the bottom. The power spectra of the displacement of the free surface and the bulk energy are numerically evaluated and the bulk energy tends to give favorable agreement with the spectra of the displacement obtained experimentally. The transition from the secondary mode flow appearing at higher Reynolds number to the primary mode flow at lower Reynolds number is examined and comparison between the numerical and experimental results are made.

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