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Coagulation and fragmentation dynamics of inertial particles
Jens C Zahnow1, Rafael D Vilela, Ulrike Feudel
1Theoretical Physics/Complex Systems, ICBM, University of Oldenburg, 26129 Oldenburg, Germany.
Summary
Particle coagulation and fragmentation in time-periodic flows reach a steady state. Fragmentation, not collision rates, dictates the final particle size distribution, showing flow independence.
Area of Science:
- Fluid dynamics
- Particle dynamics
- Nonlinear dynamics
Background:
- Inertial particles in flows can coagulate via collisions.
- Particles may fragment due to large shear or size.
- Coagulation-fragmentation is crucial in natural and industrial processes.
Purpose of the Study:
- Investigate particle coagulation-fragmentation in time-periodic incompressible flows.
- Determine the asymptotic dynamical steady state of particle size distributions.
- Analyze the influence of fragmentation mechanisms and flow properties on the steady state.
Main Methods:
- Simulated particle dynamics in time-periodic flows.
- Analyzed particle size distributions.
- Compared outcomes for two distinct fragmentation mechanisms.
- Varied flow characteristics (e.g., shear) to assess impact.
Main Results:
- The system approaches a dynamical steady state with constant average particle numbers.
- Steady-state size distributions are largely independent of the coagulation process.
- Fragmentation mechanisms primarily determine the steady-state distribution.
- Similar steady states can arise from different flow concentrations if shear variations are alike.
Conclusions:
- Fragmentation is the dominant factor in determining the steady-state particle size distribution.
- Transient behavior is governed by collision rates, while fragmentation dictates the long-term state.
- Particle size distributions in shear-driven fragmentation can be similar across diverse flow conditions.
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