Dissipative Particle Dynamics at Isoenthalpic Conditions Using Shardlow-Like Splitting Algorithms
Abstract
A numerical integration scheme based upon the Shardlow-splitting algorithm (SSA) is presented for a Dissipative Particle Dynamics (DPD) approach at fixed pressure and enthalpy. A constant-enthalpy DPD method (DPD-H) is developed by combining the equations of motion (EOM) for a barostat with the EOM for the constant - energy DPD method (DPD-E) . The DPD-H variant is developed for both a deterministic (Hoover) and stochastic (Langevin) barostat, where a barostat temperature is defined to satisfy the fluctuation-dissipation theorem for the Langevin barostat. The application of the Shardlow-splitting algorithm is particularly critical for the DPD-H variant because it allows more temporally practical simulations to be carried out. The DPD-H variant using the SSA is verified using both a standard DPD fluid model and a coarse-grain solid model. For both models, the DPD-H variant is further verified by instantaneously heating a slab of particles in the simulation cell and subsequently monitoring the evolution of the corresponding thermodynamic variables as the system approaches an equilibrated state while maintaining constant - enthalpy conditions. The Fokker-Planck equation and derivation of the fluctuation - dissipation theorem are included.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2013
- Accession Number
- ADA588131
Entities
People
- John K. Brennan
- Martin Lísal
Organizations
- United States Army Research Laboratory