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Pep Español - One of the best experts on this subject based on the ideXlab platform.

  • Perspective: Dissipative Particle Dynamics
    The Journal of chemical physics, 2017
    Co-Authors: Pep Español, Patrick B Warren
    Abstract:

    Dissipative Particle Dynamics (DPD) belongs to a class of models and computational algorithms developed to address mesoscale problems in complex fluids and soft matter in general. It is based on the notion of Particles that represent coarse-grained portions of the system under study and allow, therefore, to reach time and length scales that would be otherwise unreachable from microscopic simulations. The method has been conceptually refined since its introduction almost twenty five years ago. This perspective surveys the major conceptual improvements in the original DPD model, along with its microscopic foundation, and discusses outstanding challenges in the field. We summarize some recent advances and suggests avenues for future developments.

  • Consistent scaling of thermal fluctuations in smoothed Dissipative Particle Dynamics
    The Journal of chemical physics, 2009
    Co-Authors: Adolfo Vázquez-quesada, Marco Ellero, Pep Español
    Abstract:

    Dissipative Particle Dynamics (DPD) as a model of fluid Particles suffers from the problem that it has no physical scale associated with the Particles. Therefore, a DPD simulation requires an ambiguous fine-tuning of the model parameters with the physical parameters. A corrected version of DPD that does not suffer from this problem is smoothed Dissipative Particle Dynamics (SDPD) [P. Espanol and M. Revenga, Phys. Rev. E 67, 026705 (2003)]. SDPD is, in fact, a version of the well-known smoothed Particle hydroDynamics method, albeit with the proper inclusion of thermal fluctuations. Here, we show that SDPD produces the proper scaling of the fluctuations as the resolution of the simulation is varied. This is investigated in two problems: the Brownian motion of a spherical colloidal Particle and a polymer molecule in suspension.

  • Dissipative Particle Dynamics
    Handbook of Materials Modeling, 2005
    Co-Authors: Pep Español
    Abstract:

    In order to simulate a complex fluid like a polymeric or colloidal fluid, a molecular Dynamics simulation is not very useful. The long time and space scales involved in the mesoscopic Dynamics of large macromolecules or colloidal Particles as compared with molecular scales imply to follow an exceedingly large number of molecules during exceedingly large times. On the other hand, at these long scales, molecular details only show up in a rather coarse form, and the question arises if it is possible to deal with coarse-grained entities that reproduce the mesoscopic Dynamics correctly. Dissipative Particle Dynamics (DPD) is a fruitful modeling attempt in that direction.

  • Dissipative Particle Dynamics and Other Fluid Particle Models
    ICASE LaRC Interdisciplinary Series in Science and Engineering, 2004
    Co-Authors: Pep Español
    Abstract:

    Dissipative Particle Dynamics (DPD) is a Particle model that allows to simulate complex fluids at mesoscopic scales. Since its introduction a decade ago it has been applied to a large variety of different complex fluid systems. At the same time, generalizations of the model have been introduced in order to refine the concept of Dissipative Particle. Here, I offer my personal view about the status of DPD as a model for simulating complex fluids, review part of the literature on applications, and sketch some lines for future research.

  • Smoothed Dissipative Particle Dynamics
    Physical Review E, 2003
    Co-Authors: Pep Español, Mariano Revenga
    Abstract:

    We present a fluid Particle model that is both a thermodynamically consistent version of smoothed Particle hydroDynamics (SPH) and a version of Dissipative Particle Dynamics (DPD), capturing the best of both methods. The model is a discrete version of Navier-Stokes equations, like SPH, and includes thermal fluctuations, like DPD. This model solves some problems with the physical interpretation of the original DPD model.

Peter V Coveney - One of the best experts on this subject based on the ideXlab platform.

  • Dynamical geometry for multiscale Dissipative Particle Dynamics
    Computer Physics Communications, 2003
    Co-Authors: Gianni De Fabritiis, Peter V Coveney
    Abstract:

    In this paper, we review the computational aspects of a multiscale Dissipative Particle Dynamics model for complex fluid simulations based on the feature-rich geometry of the Voronoi tessellation. The geometrical features of the model are critical since the mesh is directly connected to the physics by the interpretation of the Voronoi volumes of the tessellation as coarse-grained fluid clusters. The Voronoi tessellation is maintained dynamically in time to model the fluid in the Lagrangian frame of reference, including imposition of periodic boundary conditions. Several algorithms to construct and maintain the periodic Voronoi tessellation are reviewed in two and three spatial dimensions and their parallel performance discussed. The insertion of polymers and colloidal Particles in the fluctuating hydrodynamic solvent is described using surface boundaries.

  • Multiscale Dissipative Particle Dynamics
    Philos Trans A Math Phys Eng Sci, 2002
    Co-Authors: Gianni De Fabritiis, Peter V Coveney, E. G. Flekkøy
    Abstract:

    We present a simplified kinetic derivation of the multiscale Voronoi-based Dissipative Particle Dynamics (DPD) method. The Voronoi tessellation is used to coarse-grain the molecular level of a fluid, resulting in mesoscopic equations of motion for local mass, momentum and energy. The Dissipative Particles follow the Dynamics of extended objects subject to forces including pressure and stresses. The stresses and heat fluxes are computed through constitutive relations, which lead to fluctuating Navier-Stokes hydroDynamics for the solvent. The present formulation is based on the use of statistical mechanical distribution functions and the connection with the underlying molecular description of the fluid is maintained through the pair-distribution function and the intermolecular potential. The main features of this DPD method are the adaptivity of the Dissipative Particles to the important length-scales of the problem and the explicit role played by the molecular pair-distribution function.

  • From Molecular Dynamics to Dissipative Particle Dynamics
    Physical Review Letters, 1999
    Co-Authors: E. G. Flekkøy, Peter V Coveney
    Abstract:

    A procedure is introduced for deriving a coarse-grained Dissipative Particle Dynamics from molecular Dynamics. The rules of the Dissipative Particle Dynamics are derived from the underlying molecular interactions, and a Langevin equation is obtained that describes the forces experienced by the Dissipative Particles and specifies the associated canonical Gibbs distribution for the system.

  • Detailed balance and H-theorems for Dissipative Particle Dynamics
    Journal of Physics a-Mathematical and General, 1998
    Co-Authors: C A Marsh, Peter V Coveney
    Abstract:

    An extension of the H-theorem for Dissipative Particle Dynamics (DPD) to the case of a multicomponent fluid is made. Detailed balance and an additional H-theorem are proved for an energy-conserving version of the DPD algorithm. The implications of these results for the statistical mechanics of the method are discussed.

  • Using Dissipative Particle Dynamics to Model Binary Immiscible Fluids
    International Journal of Modern Physics C, 1997
    Co-Authors: Keir E. Novik, Peter V Coveney
    Abstract:

    We investigate the domain growth and phase separation of two-dimensional binary immiscible fluid systems using Dissipative Particle Dynamics. Our results are compared with similar simulations using other techniques, and we conclude that Dissipative Particle Dynamics is a promising method for simulating these systems.

Patrick B Warren - One of the best experts on this subject based on the ideXlab platform.

  • Wax Formation in Linear and Branched Alkanes with Dissipative Particle Dynamics.
    Journal of chemical theory and computation, 2020
    Co-Authors: David J. Bray, Patrick B Warren, Richard L. Anderson, Kenneth Lewtas
    Abstract:

    We present a Dissipative Particle Dynamics (DPD) model for wax formation (i.e. the freezing transition) in linear and branched alkanes at room temperature (298 K) and atmospheric pressure. We param...

  • Perspective: Dissipative Particle Dynamics
    The Journal of chemical physics, 2017
    Co-Authors: Pep Español, Patrick B Warren
    Abstract:

    Dissipative Particle Dynamics (DPD) belongs to a class of models and computational algorithms developed to address mesoscale problems in complex fluids and soft matter in general. It is based on the notion of Particles that represent coarse-grained portions of the system under study and allow, therefore, to reach time and length scales that would be otherwise unreachable from microscopic simulations. The method has been conceptually refined since its introduction almost twenty five years ago. This perspective surveys the major conceptual improvements in the original DPD model, along with its microscopic foundation, and discusses outstanding challenges in the field. We summarize some recent advances and suggests avenues for future developments.

  • No-go theorem in many-body Dissipative Particle Dynamics.
    Physical review. E Statistical nonlinear and soft matter physics, 2013
    Co-Authors: Patrick B Warren
    Abstract:

    Many body Dissipative Particle Dynamics (MDPD) is a Particle-based simulation method in which the interaction potential is a sum of self energies depending on locally sampled density variables. This functional form gives rise to density-dependent pairwise forces; however, not all such force laws are derivable from a potential, and the integrability condition for this to be the case provides a strong constraint. A strategy to assess the implications of this constraint is illustrated here by the derivation of a useful no-go theorem for multicomponent MDPD.

  • Vapor-liquid coexistence in many-body Dissipative Particle Dynamics.
    Physical Review E, 2003
    Co-Authors: Patrick B Warren
    Abstract:

    Many-body Dissipative Particle Dynamics is constructed to exhibit vapor-liquid coexistence, with a sharp interface, and a vapor phase of vanishingly small density. The application to fluid mechanics problems involving free surfaces is illustrated by simulation of a pendant drop. The model is an unusual example of a soft-sphere liquid with a potential energy built out of local-density-dependent one-Particle self-energies.

  • Kinetic theory for Dissipative Particle Dynamics: the importance of collisions
    Europhysics Letters (EPL), 1999
    Co-Authors: Andrew J. Masters, Patrick B Warren
    Abstract:

    Kinetic theory of Dissipative Particle Dynamics is developed in terms of a Boltzmann pair collision theory. The kinetic transport coefficients are computed from explicit collision integrals and compared favourably with detailed simulations. Previous theory is found to correspond to a weak scattering limit, or Vlasov theory, and previously reported discrepancies with simulations are thereby resolved. In the large dissipation limit, we find qualitatively new scaling properties for the transport coefficients.

Gabriel Stoltz - One of the best experts on this subject based on the ideXlab platform.

  • Stable and accurate schemes for smoothed Dissipative Particle Dynamics
    Applied Mathematics and Mechanics, 2018
    Co-Authors: Gérôme Faure, Gabriel Stoltz
    Abstract:

    Smoothed Dissipative Particle Dynamics (SDPD) is a mesoscopic Particle method which allows to select the level of resolution at which a fluid is simulated. The numerical integration of its equations of motion still suffers from the lack of numerical schemes satisfying all the desired properties: energy conservation, parallelizability and stability. The similarities between SDPD and Dissipative Particle Dynamics with Energy conservation (DPDE), which is another coarse-grained model, enable the adaptation of recent numerical schemes developed for DPDE to the SDPD setting. In this article, we introduce a Metropolis step in the integration of the fluctuation/dissipation part of SDPD to improve its stability.

  • Stable and accurate schemes for smoothed Dissipative Particle Dynamics
    Applied Mathematics and Mechanics, 2017
    Co-Authors: Gérôme Faure, Gabriel Stoltz
    Abstract:

    Smoothed Dissipative Particle Dynamics (SDPD) is a mesoscopic Particle method that allows to select the level of resolution at which a fluid is simulated. The numerical integration of its equations of motion still suffers from the lack of numerical schemes satisfying all the desired properties such as energy conservation and stability. Similarities between SDPD and Dissipative Particle Dynamics with energy (DPDE) conservation, which is another coarse-grained model, enable adaptation of recent numerical schemes developed for DPDE to the SDPD setting. In this article, a Metropolis step in the integration of the fluctuation/dissipation part of SDPD is introduced to improve its stability.

  • Stable schemes for Dissipative Particle Dynamics with conserved energy
    Journal of Computational Physics, 2017
    Co-Authors: Gabriel Stoltz
    Abstract:

    This article presents a new numerical scheme for the discretization of Dissipative Particle Dynamics with conserved energy. The key idea is to reduce elementary pairwise stochastic Dynamics (either fluctuation/dissipation or thermal conduction) to effective one-dimensional Dynamics, and to approximate the solution of these Dynamics with one step of a Metropolis-Hastings algorithm. This ensures by construction that no negative internal energies are encountered during the simulation, and hence allows to increase the admissible timesteps to integrate the Dynamics, even for systems with small heat capacities. Stability is only limited by the Hamiltonian part of the Dynamics, which suggests resorting to multiple timestep strategies where the stochastic part is integrated less frequently than the Hamiltonian one.

  • Size consistency in smoothed Dissipative Particle Dynamics.
    Physical review. E, 2016
    Co-Authors: Gérôme Faure, Jean-bernard Maillet, Julien Roussel, Gabriel Stoltz
    Abstract:

    Smoothed Dissipative Particle Dynamics (SDPD) is a mesoscopic method that allows one to select the level of resolution at which a fluid is simulated. In this work, we study the consistency of the resulting thermodynamic properties as a function of the size of the mesoParticles, both at equilibrium and out of equilibrium. We also propose a reformulation of the SDPD equations in terms of energy variables. This increases the similarities with Dissipative Particle Dynamics with energy conservation and opens the way for a coupling between the two methods. Finally, we present a numerical scheme for SDPD that ensures the conservation of the invariants of the Dynamics. Numerical simulations illustrate this approach.

  • Size consistency in smoothed Dissipative Particle Dynamics
    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 2016
    Co-Authors: G??r??me Faure, Jean-bernard Maillet, Julien Roussel, Gabriel Stoltz
    Abstract:

    Smoothed Dissipative Particle Dynamics (SDPD) is a mesoscopic method which allows to select the level of resolution at which a fluid is simulated. In this work, we study the consistency of the resulting thermodynamic properties as a function of the size of the mesoParticles, both at equilibrium and out of equilibrium. We also propose a reformulation of the SDPD equations in terms of energy variables. This increases the similarities with Dissipative Particle Dynamics with Energy conservation and opens the way for a coupling between the two methods. Finally, we present a numerical scheme for SDPD that ensures the conservation of the invariants of the Dynamics. Numerical simulations illustrate this approach.

Nikolaus A. Adams - One of the best experts on this subject based on the ideXlab platform.

  • Multiscale modeling of Particle in suspension with smoothed Dissipative Particle Dynamics
    Physics of Fluids, 2012
    Co-Authors: Xin Bian, Marco Ellero, Sergey Litvinov, Rui Qian, Nikolaus A. Adams
    Abstract:

    We apply smoothed Dissipative Particle Dynamics (SDPD) [Espanol and Revenga, Phys. Rev. E 67, 026705 (2003)] to model solid Particles in suspension. SDPD is a thermodynamically consistent version of smoothed Particle hydroDynamics (SPH) and can be interpreted as a multiscale Particle framework linking the macroscopic SPH to the mesoscopic Dissipative Particle Dynamics (DPD) method. Rigid structures of arbitrary shape embedded in the fluid are modeled by frozen Particles on which artificial velocities are assigned in order to satisfy exactly the no-slip boundary condition on the solid-liquid interface. The Dynamics of the rigid structures is decoupled from the solvent by solving extra equations for the rigid body translational/angular velocities derived from the total drag/torque exerted by the surrounding liquid. The correct scaling of the SDPD thermal fluctuations with the fluid-Particle size allows us to describe the behavior of the Particle suspension on spatial scales ranging continuously from the dif...

  • Self-diffusion coefficient in smoothed Dissipative Particle Dynamics
    The Journal of chemical physics, 2009
    Co-Authors: Sergey Litvinov, Marco Ellero, Nikolaus A. Adams
    Abstract:

    Smoothed Dissipative Particle Dynamics (SDPD) is a novel coarse grained method for the numerical simulation of complex fluids. It has considerable advantages over more traditional Particle-based methods. In this paper we analyze the self-diffusion coefficient D of a SDPD solvent by using the strategy proposed by Groot and Warren [J. Chem. Phys. 107, 4423 (1997)]. An analytical expression for D in terms of the model parameters is developed and verified by numerical simulations.

  • Dissipative Particle Dynamics for Modeling Complex Fluidics
    Multiscale Modelling and Simulation, 2004
    Co-Authors: Justyna Czerwinska, Nikolaus A. Adams
    Abstract:

    In this paper we present a new formulation of a Dissipative Particle Dynamics (DPD) model which is computationally less expensive than Voronoi-based DPD while preserving most of the advantages of Voronoi DPD over simple spherical-Particle models. Aiming at fully three-dimensional flows an alternative to the straight-forward application of Voronoi DPD is desirable. The new model presented here can be derived from the Molecular Dynamics level by a coarse graining procedure (bottom-up approach) as well as from the continuum or macro-scale level conservation equations (top-down approach). In this paper the bottom-up derivation is presented.