Dresden 2017 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 62: Complex Fluids and Soft Matter II (joint DY/CPP)

DY 62.7: Talk

Friday, March 24, 2017, 11:30–11:45, HÜL 186

A nearly incompressible mesoscopic method for simulating complex fluids and flows — •Davod Alizadehrad and Dmitry A. Fedosov — Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany

Numerical simulation and theoretical modeling of mesoscopic processes are constantly challenged by the large separation of time scales and length scales. We introduce a general mesoscopic framework for simulating complex liquids and flows using the smoothed dissipative particle dynamics [1]. Modifying the equation of state and the course-grained system, we show that the speed of sound can be controlled, while the radial distribution function (RDF), the mean-square displacement, and the Schmidt number correspond to liquid state, even for low temperatures. Performing reverse-Poiseuille flow simulations, measured viscosity shows only 1-2 percent changes over several orders variation of shear rates. The RDF in equilibrium and in shear flow remains same and independent of shear rates. This is an advantage in modeling of structures and boundaries either rigid or deformable. As a challenging test of incompressibility, we have considered the Poisson ratio, divergence of velocity field, and the number density in elongational flow. Density variation remains smaller than one percent and the velocity field satisfies well the divergence-free condition, indicating that the simulated fluid is nearly incompressible. Finally, we present the applicability and validity of the method in simulating cellular blood flow in irregular geometries as an example of complex mesoscopic fluids flow.

[1] K. Müller, et al., J. Comp. Phys. 281, 301-315, (2015)