Multiparticle collision dynamics simulations of viscoelastic fluids: shear-thinning Gaussian dumbbells
Bartosz Kowalik1, Roland G Winkler
1Theoretical Soft Matter and Biophysics, Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany.
The Journal of Chemical Physics
|March 22, 2013
Summary
This study introduces a modified multiparticle collision dynamics (MPC) fluid using Gaussian dumbbells, demonstrating shear-thinning behavior and a non-zero second normal stress coefficient. The findings align well with analytical predictions for complex fluid simulations.
Area of Science:
- Complex fluid dynamics
- Mesoscale simulation techniques
- Rheology of polymers
Background:
- Multiparticle collision dynamics (MPC) is a mesoscale simulation method for complex fluids.
- Existing MPC models often use Newtonian solvents, limiting their application to shear-thinning fluids.
- Gaussian dumbbells offer a way to model complex fluid behavior efficiently.
Purpose of the Study:
- To investigate the structural, dynamical, and rheological properties of a shear-thinning fluid.
- To adapt the multiparticle collision dynamics (MPC) method using Gaussian dumbbells.
- To compare simulation results with analytical predictions under nonequilibrium conditions.
Main Methods:
- Utilized multiparticle collision dynamics (MPC) with Gaussian dumbbells.
- Enforced constant mean square length for Gaussian dumbbells under nonequilibrium conditions.
- Employed the preaveraging approximation for hydrodynamic interactions.
Main Results:
- Achieved shear-thinning behavior in the modified MPC fluid.
- Observed a nonzero second normal stress coefficient.
- Demonstrated good agreement between analytical and simulation results, with minor deviations attributed to the approximation.
Conclusions:
- The modified MPC method accurately captures shear-thinning properties of complex fluids.
- Gaussian dumbbells provide an efficient and accurate representation within MPC simulations.
- The study validates the analytical approach for predicting rheological properties in nonequilibrium flows.
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