Experimental studies of turbulent Taylor-Couette flows: single phase and liquid-liquid dispersions

Ravelet, Florent; Delfos, Rene; Westerweel, Jerry

Experimental studies of turbulent Taylor-Couette flows: single phase and liquid-liquid dispersions

Authors

Ravelet, Florent

Delfos, Rene

Westerweel, Jerry

Description

We study liquid-liquid dispersions in a turbulent Taylor-Couette flow, produced between two counterrotating coaxial cylinders. In pure Water and in counterrotation, Reynolds numbers up to 1.4 10^5 are reached. The liquids we use are a low-viscous Oil and pure Water or a Sodium Iodide solution with a refractive index matched to that of Oil, in order to get transparent dispersions. We first characterize the single-phase flow, in terms of threshold for transition to turbulence, scaling of the torque and measurements of the mean flow and of the Reynolds stress by stereoscopic PIV. We then study the increase of the dissipation in the two-phase flows and find that the torque per unit mass can be twice the torque for a single-phase flow. Long-time behaviours are also reported.
5th International Symposium on Turbulence and Shear Flow Phenomena, Munich : Allemagne (2007)