0000000000755282

AUTHOR

Nehzat Emamy

showing 2 related works from this author

Molecular dynamics simulations in hybrid particle-continuum schemes: Pitfalls and caveats

2017

Heterogeneous multiscale methods (HMM) combine molecular accuracy of particle-based simulations with the computational efficiency of continuum descriptions to model flow in soft matter liquids. In these schemes, molecular simulations typically pose a computational bottleneck, which we investigate in detail in this study. We find that it is preferable to simulate many small systems as opposed to a few large systems, and that a choice of a simple isokinetic thermostat is typically sufficient while thermostats such as Lowe-Andersen allow for simulations at elevated viscosity. We discuss suitable choices for time steps and finite-size effects which arise in the limit of very small simulation bo…

Computer scienceGeneral Physics and AstronomySolverCondensed Matter - Soft Condensed Matter01 natural sciencesThermostatBottleneck010305 fluids & plasmaslaw.invention010101 applied mathematicsMolecular dynamicsHardware and ArchitectureDiscontinuous Galerkin methodlaw0103 physical sciencesSoft matterStatistical physics0101 mathematicsShear flowHidden Markov model
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Implicit-explicit and explicit projection schemes for the unsteady incompressible Navier–Stokes equations using a high-order dG method

2017

Abstract A modified version of the projection scheme [19] is proposed, which does not show a lower limit for the time step in contrast to the limits of stability observed numerically for some projection type schemes. An advantage of the proposed scheme is that the right-hand side of the Poisson equation for the pressure is independent of the time step. An explicit version of the current scheme is also provided besides the implicit-explicit one. For the implicit-explicit version, we retain divergence of the viscous terms on the right-hand side of the Poisson equation in order to achieve a higher accuracy for low Reynolds number flows. In this way, we also ensure that the Poisson equation wit…

General Computer ScienceDiscretizationPlane (geometry)Mathematical analysisGeneral Engineering01 natural sciencesProjection (linear algebra)010305 fluids & plasmas010101 applied mathematicsIncompressible flow0103 physical sciencesNeumann boundary conditionBoundary value problem0101 mathematicsPoisson's equationNavier–Stokes equationsMathematicsComputers & Fluids
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