Experimental Investigations of the Surface Groove Effect in Taylor-Couette-Poiseuille Flow

Abstract

Abstract In this paper, we investigate the effects of an imposed axial flow on hydrodynamic instabilities’ Couette-Taylor flow in the case where the wall of the inner cylinder of the system is grouved. Without imposed axial flow, the basic flow of a fluid between two coaxial cylinders known by Couette flow, which is characterized by several temporal and spatial symmetries. The increase in the rotation causes the breaking of these symmetries. In both cases where the surface of the inner cylinder is smooth and grooved, five different flow regimes can be determined: Taylor vortex flow (TVF), wavy vortex flow (WVF), and Modulated Wavy vortex flow (MWVF). Each time the flow passes from one hydrodynamic regime to another until it enters a state of turbulence, which is characterized by the destruction of all the symmetries that existed at the beginning. In addition, when an axial flow is imposed on a Taylor-Couette flow, new helical vortex structures are observed in both cases (with and without surface groove). The influence of surface structures (grooves) on the shear stress of the wall is discussed with and without axial base flow. A spatio-temporal description of several flow models was obtained using firstly, a visualization’s qualitative study using kalliroscope particles. Secondly, a quantitative study by polarography using simple probes have been used to characterize the impact of vortex structures on the Couette-Taylor flows without and with an axial flow on the transfer.