Arrow-shaped elasto-inertial rotating waves

Area of Science:

• Fluid Dynamics
• Polymer Physics
• Computational Science

Background:

• Taylor-Couette flow is a fundamental problem in fluid dynamics.
• Understanding polymer solution behavior in complex flows is crucial for industrial applications.
• Previous studies have explored various flow regimes, but elasto-inertial waves with specific structures remained elusive.

Purpose of the Study:

• To investigate the dynamics of dilute polymer solutions in Taylor-Couette flow using direct numerical simulations.
• To identify and characterize novel flow states, particularly those involving polymer elasticity.
• To analyze the influence of system curvature, Reynolds number, and Weissenberg number on flow patterns.

Main Methods:

• Direct numerical simulations (DNS) were employed to model the flow.
• The finitely extensible nonlinear elastic-Peterlin (FENE-P) closure model was used for polymer dynamics.
• Flow states were analyzed, focusing on the polymer stretch field and its alignment with the streamwise direction.

Main Results:

• A novel elasto-inertial rotating wave was discovered, characterized by arrow-shaped polymer stretch structures.
• These structures are aligned with the streamwise direction and depend on Reynolds and Weissenberg numbers.
• New flow states with coexisting arrow-shaped and other structures were identified.

Conclusions:

• The study demonstrates the existence of a unique elasto-inertial rotating wave in curved polymer flows.
• The findings provide a detailed characterization of these structures and their dependencies.
• This research contributes to the understanding of complex fluid behavior in Taylor-Couette systems.