Multiscale simulation for thermo-hydrodynamic lubrication of a polymeric liquid between parallel plates

Yasuda, Shugo; Yamamoto, Ryōichi

doi:10.1080/08927022.2014.951639

Cited by 3 publications

(3 citation statements)

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“…It should be noted that in previous studies [22,23,24], a severely jammed state of polymers was considered, so that the difference of the thermo-rheological property between the present entangled polymer fluid and the previous unentangled polymer fluid may be related to the initial condition of the density ρ0 and temperature T0. The molecular mechanism behind the different thermo-rheological property remains an open question.…”

Section: Resultsmentioning

confidence: 99%

“…In this paper, we tackle the thermal lubrication of entangled polymer chains by using the SMD method. This study is the extension of a series of previous studies on an unentangled polymer fluid [22,23,24] to the entangled polymer fluid. In the previous studies, a counter-intuitive transitional behavior induced by viscous heating was discovered in the dynamics of polymer conformation.…”

Section: Introductionmentioning

confidence: 93%

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Synchronized Molecular-Dynamics Simulation of the Thermal Lubrication of an Entangled Polymeric Liquid

Yasuda

2019

Polymers

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The thermal lubrication of an entangled polymeric liquid in wall-driven shear flows between parallel plates is investigated by using a multiscale hybrid method, coupling molecular dynamics and hydrodynamics (i.e., the synchronized molecular dynamics method). The temperature of the polymeric liquid rapidly increases due to viscous heating once the drive force exceeds a certain threshold value, and the rheological properties drastically change at around the critical drive force. In the weak viscous-heating regime, the conformation of polymer chains is dominated by the flow field so that the polymers are more elongated as the drive force increases. However, in the large viscous-heating regime, the conformation dynamics is dominated by the thermal agitation of polymer chains so that the conformation of polymers recovers more uniform and random structures as the drive force increases, even though the local shear flows are further enhanced. Remarkably, this counter-intuitive transitional behavior gives an interesting re-entrant transition in the stress–optical relation, where the linear stress–optical relation approximately holds even though each of the macroscopic quantities behaves nonlinearly. Furthermore, the shear thickening behavior is also observed in the large viscous-heating regime—this was not observed in a series of previous studies on an unentangled polymer fluid. This qualitative difference of the thermo-rheological property between the entangled and unentangled polymer fluids gives completely different velocity profiles in the thermal lubrication system.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 93%

Synchronized Molecular-Dynamics Simulation of the Thermal Lubrication of an Entangled Polymeric Liquid

Yasuda

2019

Polymers

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“…Recently, we proposed the synchronized molecular dynamics (SMD) method for thermal lubrication flows of polymeric liquids, in which the local viscous heating is autonomously generated in the local MD cell according to the local shear flow. The local MD cells are also synchronized to satisfy the global heat and momentum transports [23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Synchronized Molecular-Dynamics Simulation of the Thermal Lubrication of an Entangled Polymeric Liquid

Yasuda

2018

Preprint

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The thermal lubrication of an entangled polymeric liquid in wall-driven shear flows between parallel plates is investigated by using a multiscale hybrid method coupling molecular dynamics and the hydrodynamics (i.e., the synchronized molecular dynamics method). The temperature of the polymeric liquid rapidly increases due to viscous heating once the drive force exceeds a certain threshold value. The rheological properties of the polymeric liquid drastically change at around the critical drive force. In the weak viscous-heating regime, the conformation of polymer chains is dominated by the local shear flow so that the anisotropy of the bond orientation tensor grows as the drive force increases. However, in the large viscous-heating regime, the conformation dynamics is dominated by the thermal agitation of polymer chains so that the bond orientation tensor recovers more uniform and random structures as the drive force increases, even though the local shear flows are further enhanced. Remarkably, these counter-intuitive transitional behaviors give an interesting re-entrant transition in the stress--optical relation, where a linear formalism in the stress--optical relation approximately holds even though each of the macroscopic quantities behaves nonlinearly. The robustness of the linear stress--optical relation is also confirmed in the spatiotemporal evolution at the hydrodynamic level.

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Developments of Accurate Simulations for Particle Dispersions

Yamamoto

Molina

2014

Hosokawa Foundation ANNUAL REPORT

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We developed a unique numerical method for direct numerical simulations (DNS) of dense colloidal dispersions. This method, called the smoothed profile method (SPM), enables us to compute the time evolutions of colloidal particles, ions, and host fluids simultaneously by solving Newton, advection-diffusion, and Navier-Stokes equations so that the electro-hydrodynamic couplings can be fully taken into account. We

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Multiscale simulation for thermo-hydrodynamic lubrication of a polymeric liquid between parallel plates

Cited by 3 publications

References 27 publications

Synchronized Molecular-Dynamics Simulation of the Thermal Lubrication of an Entangled Polymeric Liquid

Synchronized Molecular-Dynamics Simulation of the Thermal Lubrication of an Entangled Polymeric Liquid

Synchronized Molecular-Dynamics Simulation of the Thermal Lubrication of an Entangled Polymeric Liquid

Developments of Accurate Simulations for Particle Dispersions

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