Exploring the origin of turbulent Taylor rolls

Area of Science:

• Fluid Dynamics
• Turbulence Studies
• Non-equilibrium Physics

Background:

• Taylor-Couette flow is a key model for studying fluid dynamics.
• The existence of large-scale quasi-axisymmetric structures in this flow, particularly in the turbulent regime, remains an area of significant interest.
• Understanding these structures is crucial for advancing knowledge in turbulence and convective flows.

Purpose of the Study:

• To investigate the formation and characteristics of large-scale quasi-axisymmetric structures in the highly turbulent regime of Taylor-Couette flow.
• To analyze the impact of varying Coriolis parameters on flow dynamics.
• To elucidate the role of Coriolis forces in coupling velocity fields and influencing structure formation.

Main Methods:

• Numerical simulations were conducted at a fixed Reynolds number.
• The Coriolis parameter was systematically varied to observe its effects on flow characteristics.
• Flow statistics were analyzed and compared with a similar shear flow lacking no-slip boundary layers.

Main Results:

• The Coriolis force induces a one-way coupling between radial and azimuthal velocities in the boundary layer.
• A two-way coupling occurs in the bulk flow, leading to competing effects and complicating analogies with other convective flows.
• Significant differences in flow effects were observed compared to shear flows without no-slip boundary layers.

Conclusions:

• The complex, double-acting coupling induced by Coriolis forces plays a critical role in the formation and behavior of turbulent Taylor rolls.
• The findings highlight the unique dynamics of Taylor-Couette flow, especially under the influence of Coriolis forces.
• This research contributes to understanding the origins of turbulent structures in rotating fluid systems.