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Title: Molecular shear heating and vortex dynamics in thermostatted two dimensional Yukawa liquids

Abstract

It is well known that two-dimensional macroscale shear flows are susceptible to instabilities leading to macroscale vortical structures. The linear and nonlinear fate of such a macroscale flow in a strongly coupled medium is a fundamental problem. A popular example of a strongly coupled medium is a dusty plasma, often modelled as a Yukawa liquid. Recently, laboratory experiments and molecular dynamics (MD) studies of shear flows in strongly coupled Yukawa liquids indicated the occurrence of strong molecular shear heating, which is found to reduce the coupling strength exponentially leading to the destruction of macroscale vorticity. To understand the vortex dynamics of strongly coupled molecular fluids undergoing macroscale shear flows and molecular shear heating, MD simulation has been performed, which allows the macroscopic vortex dynamics to evolve, while at the same time “removes” the microscopically generated heat without using the velocity degrees of freedom. We demonstrate that by using a configurational thermostat in a novel way, the microscale heat generated by shear flow can be thermostatted out efficiently without compromising the large scale vortex dynamics. In the present work, using MD simulations, a comparative study of shear flow evolution in Yukawa liquids in the presence and absence of molecular or microscopicmore » heating is presented for a prototype shear flow, namely, Kolmogorov flow.« less

Authors:
;  [1];  [2]
  1. Institute for Plasma Research, HBNI, Bhat Gandhinagar, Gujarat 382 428 (India)
  2. Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India)
Publication Date:
OSTI Identifier:
22600034
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 23; Journal Issue: 7; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPUTERIZED SIMULATION; DEGREES OF FREEDOM; FOKKER-PLANCK EQUATION; HEAT; HEATING; INSTABILITY; LIQUIDS; MOLECULAR DYNAMICS METHOD; NONLINEAR PROBLEMS; PLASMA; SHEAR; THERMOSTATS; TWO-DIMENSIONAL CALCULATIONS; VELOCITY; VORTICES; YUKAWA POTENTIAL

Citation Formats

Gupta, Akanksha, Ganesh, Rajaraman, E-mail: ganesh@ipr.res.in, and Joy, Ashwin. Molecular shear heating and vortex dynamics in thermostatted two dimensional Yukawa liquids. United States: N. p., 2016. Web. doi:10.1063/1.4958943.
Gupta, Akanksha, Ganesh, Rajaraman, E-mail: ganesh@ipr.res.in, & Joy, Ashwin. Molecular shear heating and vortex dynamics in thermostatted two dimensional Yukawa liquids. United States. doi:10.1063/1.4958943.
Gupta, Akanksha, Ganesh, Rajaraman, E-mail: ganesh@ipr.res.in, and Joy, Ashwin. Fri . "Molecular shear heating and vortex dynamics in thermostatted two dimensional Yukawa liquids". United States. doi:10.1063/1.4958943.
@article{osti_22600034,
title = {Molecular shear heating and vortex dynamics in thermostatted two dimensional Yukawa liquids},
author = {Gupta, Akanksha and Ganesh, Rajaraman, E-mail: ganesh@ipr.res.in and Joy, Ashwin},
abstractNote = {It is well known that two-dimensional macroscale shear flows are susceptible to instabilities leading to macroscale vortical structures. The linear and nonlinear fate of such a macroscale flow in a strongly coupled medium is a fundamental problem. A popular example of a strongly coupled medium is a dusty plasma, often modelled as a Yukawa liquid. Recently, laboratory experiments and molecular dynamics (MD) studies of shear flows in strongly coupled Yukawa liquids indicated the occurrence of strong molecular shear heating, which is found to reduce the coupling strength exponentially leading to the destruction of macroscale vorticity. To understand the vortex dynamics of strongly coupled molecular fluids undergoing macroscale shear flows and molecular shear heating, MD simulation has been performed, which allows the macroscopic vortex dynamics to evolve, while at the same time “removes” the microscopically generated heat without using the velocity degrees of freedom. We demonstrate that by using a configurational thermostat in a novel way, the microscale heat generated by shear flow can be thermostatted out efficiently without compromising the large scale vortex dynamics. In the present work, using MD simulations, a comparative study of shear flow evolution in Yukawa liquids in the presence and absence of molecular or microscopic heating is presented for a prototype shear flow, namely, Kolmogorov flow.},
doi = {10.1063/1.4958943},
journal = {Physics of Plasmas},
number = 7,
volume = 23,
place = {United States},
year = {Fri Jul 15 00:00:00 EDT 2016},
month = {Fri Jul 15 00:00:00 EDT 2016}
}