Flow and mass transfer characteristics for interacting side-by-side cylinders

Area of Science:

• Fluid Dynamics
• Hydrodynamics
• Mass Transfer

Background:

• Understanding fluid flow around multiple bluff bodies is crucial in various engineering applications.
• Interactions between cylinders significantly alter flow patterns compared to isolated bodies.

Purpose of the Study:

• To investigate the flow structures and mass transfer of interacting side-by-side cylinders.
• To identify distinct flow regimes and their impact on hydrodynamic forces and mass transfer coefficients.
• To analyze the influence of cylinder arrangement (pitch-ratio) and configuration size.

Main Methods:

• Numerical simulation of 2-5 cylinders in unbounded flow at Reynolds number 90.
• Analysis of time-averaged and instantaneous flow features (wake, vortical structures, pressure, mass transfer).
• Identification of flow regimes based on vortical structures and velocity fields.

Main Results:

• Four flow regimes were identified: single bluff body, deflected wakes (asymmetric/symmetric), and isolated body behavior.
• Hydrodynamic forces and mass transfer coefficients showed jumps between regimes.
• Drag increased with depth in the configuration; lift forces were repulsive.
• Mass transfer coefficients varied with cylinder position and pitch-ratio.

Conclusions:

• Flow regime dictates hydrodynamic and mass transfer characteristics.
• Cylinder configuration and size significantly influence flow behavior and scalar values, particularly at low pitch-ratios.
• Exterior cylinders experience higher mass transfer at low pitch-ratios, while interior cylinders' drag increases with depth.