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Multi-particle collision dynamics with a non-ideal equation of state. I
1Institute of Theoretical Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany.
The Journal of Chemical Physics
|January 15, 2021
Summary
We developed a new algorithm for multi-particle collision dynamics (MPCD) simulations. This method reduces fluid compressibility and computational cost, offering a more accurate and efficient approach for soft matter physics research.
Area of Science:
- Soft matter physics
- Computational fluid dynamics
- Statistical mechanics
Background:
- Multi-particle collision dynamics (MPCD) is widely used for micron-scale fluid simulations.
- Standard MPCD models ideal gas behavior, leading to high fluid compressibility and density inhomogeneities.
- This compressibility contrasts with real fluids, which are largely incompressible at low velocities.
Purpose of the Study:
- To develop a modified MPCD algorithm with reduced compressibility.
- To achieve a non-ideal equation of state for improved simulation accuracy.
- To decrease computational costs compared to conventional MPCD methods.
Main Methods:
- Proposed a modified MPCD collision rule to alter the equation of state.
- Derived analytic expressions for the equation of state, compressibility, and shear viscosity.
- Validated the algorithm through simulations of bulk fluid (pressure) and shear flow (viscosity).
Main Results:
- The modified MPCD algorithm yields a non-ideal equation of state.
- Achieved significantly decreased fluid compressibility.
- Analytic predictions for equation of state and viscosity show excellent agreement with simulation data.
- Demonstrated reduced computational cost compared to standard MPCD.
Conclusions:
- The novel MPCD algorithm accurately simulates less compressible fluids.
- This method offers a more efficient and realistic approach for soft matter simulations.
- The derived analytic expressions provide valuable tools for theoretical analysis and validation.
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