Key points are not available for this paper at this time.
Taylor–Couette flow with a high Taylor number and large radius ratio is widely present in fluid machinery, such as the internal clearance flow in a canned motor pump typically. Taylor–Couette flow with radius ratios from 0.934 to 0.977 and Taylor number from 107 to 1010 was investigated by numerical simulations. The results indicated that torque is positively correlated to radius ratio, while dimensionless torque is exponentially related to the Taylor number. Subsequently, the physical characteristics of the flow field were described by extracting statistical quantities such as the average azimuthal velocity profile, velocity fluctuations, and near-wall region analysis at four internal cylinder rotation frequencies and four radius ratios. The results revealed that increasing rotation frequency would increase velocity gradients near the wall, while higher radius ratios would produce more uniform velocity fluctuation distributions. In addition, near-wall profiles showed a constant shear force layer, while the logarithmic layer was affected by rotation frequency and radius ratio. The detailed analysis revealed that as the rotation frequency increased, the flow gradually transitioned to a turbulent state, intensifying the interaction between large and small vortex structures. The rotation speeds of Taylor vortices remained consistent across different radius ratios, with smaller scales and more numerous vortices observed at larger ratios. Smaller radius ratios led to more fine-scale vortex structures near the cylindrical wall, significantly impacting azimuthal velocity fluctuations. Finally, near-wall velocity streaks are presented to demonstrate their periodic nature and the relationship between high-speed and low-speed regions, as well as their interaction with the wall and changes with distance.
Zhang et al. (Tue,) studied this question.