SMuK 2023 – scientific programme

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P: Fachverband Plasmaphysik

P 17: Complex Plasmas and Dusty Plasmas/Codes and Modeling II

P 17.4: Talk

Thursday, March 23, 2023, 16:30–16:45, CHE/0089

Viscosity of finite Yukawa liquids — •Yang Liu, Natascha Blosczyk, and Dietmar Block — IEAP, Christian-Albrechts-Universität, D-24098 Kiel, Germany

Viscosity is one of the basic characteristics to describe the dynamic behavior of a fluid. For dusty plasmas established methods exist to measure viscosity [1,2]. However, these methods are limited to large/infinite systems while in some experiments (e.g for binary mixtures) the system size is limited. Whether and how these methods can be adapted to measure the shear viscosity of a finite two-dimensional (2D) Yukawa liquid is presented in this contribution using non-equilibrium Langevin simulations. Two counter-propagating shear forces are used to push the particles, causing shear-induced melting of the cluster. Based on the Green-Kubo relation (which relies on the random thermal motion of individual particles of the liquids) we obtain a reliable shear viscosity by diminishing the effect of shear and boundary conditions. We find that the shear viscosity is in good agreement with the results in Refs. [1, 2] if an effective coupling parameter Γ* is used. Surprisingly, the shear viscosity with this normalization follows a simple universal scaling. For Γ*>20 and 0.5<κ<2, the shear viscosity increases monotonously, and thermal motion positively affects the transport properties of dust particles.

References

[1] B. Liu and J. Goree, Physical review letters 94, 185002 (2005).

[2] Z. Donkó, J. Goree, P. Hartmann, and K. Kutasi, Phys. Rev. Lett. 96, 145003 (2006).