Laminar-turbulent transition regimes in the conical Taylor-Couette flow system

Abstract

The present work is intended to experimentally study the Taylor-Couette flow between coaxial cones. The inner cone is rotated and the outer cone is maintained fixed. Both cones have the same apex angle Φ =12°, giving a constant annular gap δ =0.12. The height of the fluid column is H=155 mm. The working fluid is assumed as Newtonian and has constant properties (as density and viscosity) within the range of the required experimental conditions. By means of visualization techniques, the critical thresholds related to the onset of various instabilities have been obtained and the corresponding flow modes have been identified. Using images processing, spatio-temporal diagrams have also been calculated, showing the characteristics (wavelength, drift velocity) of the downward helical motion. The results obtained for these transition regimes are compared to those of Wimmer et al. [1-3].