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DY: Fachverband Dynamik und Statistische Physik

DY 58: Poster - Fluids

DY 58.9: Poster

Donnerstag, 19. März 2015, 16:00–18:00, Poster A

Effects of temperature on spinodal decomposition in liquid-vapor systems — •Martin Pütz and Peter Nielaba — University of Konstanz, Germany

We use the ``Smoothed Particle Hydrodynamics`` (SPH) simulation method to investigate the dynamics and thermal evolution of spinodal decomposition of instantaneously temperature-quenched liquid-vapor systems. The numerical approach follows a modern formulation of SPH with a van der Waals equation of state, thermal conduction and a simple scaling thermostat that allows thermal fluctuations at a constant predicted mean temperature. The results are in excellent agreement with theoretical predictions for all time regimes from the initial growth of ``homophase fluctuations'' up to the inertial hydrodynamics regime. We find that the initial stage spinodal decomposition is strongly affected by the temperature field. The domain growth in the late stage of demixing is found to be rather unaffected by thermal fluctuations. However, the crossover between these stages is found to occur earlier in time for higher initial temperatures. We explain this dependency with the phase interfaces that become diffuse and hence overlap when the predicted temperature becomes closer to the critical point.