Flow patterns in a rotating horizontal cylinder partially filled with liquid.

Area of Science:

• Fluid Dynamics
• Physics of Rotating Systems

Background:

• An annular layer of low-viscosity liquid in a horizontal cylinder undergoes azimuthal oscillations due to gravity.
• Understanding the stability of this 2D azimuthal flow is crucial for predicting complex fluid behaviors.

Purpose of the Study:

• To experimentally investigate the dynamics of an annular liquid layer within a rapidly rotating horizontal cylinder.
• To identify and characterize novel axisymmetric liquid flow patterns under gravitational and rotational forces.

Main Methods:

• Experimental study of liquid dynamics in a rotating horizontal cylinder.
• Analysis of the stability of two-dimensional azimuthal flow.
• Observation and characterization of emergent axisymmetric flow structures.

Main Results:

• Discovery of a large-scale, axially symmetric flow near end walls, driven by inertial modes in corner regions.
• Identification of small-scale Taylor-Gortler vortices resulting from centrifugal instability of the oscillatory flow.
• Observed vortex spatial period aligns with studies on cellular flow in librating containers.

Conclusions:

• The study reveals two novel axisymmetric flow regimes in a rotating annular liquid system.
• Inertial modes and centrifugal instability are key mechanisms driving these distinct flow patterns.
• Findings contribute to the understanding of fluid behavior in confined, rotating environments.