Interparticle collision mechanism in turbulence.

Area of Science:

• Fluid Dynamics
• Turbulence Research
• Particle-Laden Flows

Background:

• Understanding interparticle collisions is crucial in turbulent flows.
• Particle dynamics are governed by Stokes drag and hard-sphere interactions.
• Fluid turbulence is typically solved using pseudospectral methods.

Purpose of the Study:

• To investigate interparticle collisions across a wide range of Stokes numbers.
• To analyze conditional statistics of fluid rotation and dissipation rates experienced by particles.
• To explore collision statistics including time intervals and angles.

Main Methods:

• Direct numerical simulations of homogeneous isotropic turbulence.
• Modeling particle dynamics with Stokes drag and hard-sphere collisions.
• Utilizing a pseudospectral method for fluid turbulence simulation.

Main Results:

• Collision events are found to occur predominantly in the edge regions of vortical structures.
• This phenomenon is most pronounced in the intermediate Stokes number regime.
• Conditional statistics of fluid rotation and dissipation rates provide insights into collision processes.

Conclusions:

• The sling effect near vortex edges enhances particle collisions.
• Intermediate Stokes numbers are key for increased collision and clustering.
• Findings offer essential information for modeling particle-laden turbulent flows.