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Your search keyword '"*RAREFIED gas dynamics flow"' showing total 2 results
Start Over Descriptor "*RAREFIED gas dynamics flow" Publisher emerald publishing limited
2 results on '"*RAREFIED gas dynamics flow"'

1. Analysis of velocity slipping at wall boundary under rarefied gas condition based on the effect of viscosity.

Author

Yang, Shaohua, Long, Wei, and Ning, Fangwei

Subjects
*RAREFIED gas dynamics flow, *VISCOSITY, *AEROSTATICS, *CONTINUOUS flow reactors, *MOLECULAR dynamics, *TEMPERATURE effect
Abstract

Purpose Velocity slipping model, based on the stratification theory (the film in inflatable support area of aerostatic guide way was divided into near wall layer, thin layer and continuous flow layer in the direction of height), was established, and the model was combined with viscosity changes in each layer.Design/methodology/approach Simulated and analyzed by LAMMPS and two-dimensional molecular dynamics method, some relevant conclusions were drawn.Findings At a high temperature, viscosity is low, velocity slipping is large and velocity gaps in near-wall layer and thin layer are large. When the temperature is constant, the dimensionless slipping length and Kn number are linear.Research limitations/implications The effect of the equivalent viscosity on gas slipping model is proposed. viscosity is smaller, gas velocity slipping is greater, temperature is higher, gas velocity slipping is greater, velocity gap of near wall layer and thin layer is larger. When the temperature is constant, the dimensionless slipping length ls and Kn number are linear.Originality/value The global model of lubricating film velocity slipping between plates was established, and mathematical expression of slipping model in each layer, based on the stratification theory, was presented. [ABSTRACT FROM AUTHOR]

Published
2018
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2. Study of gaseous velocity slip in nano-channel using molecular dynamics simulation.

Author

Bao, Fubing, Mao, Zhihong, and Qiu, Limin

Subjects
*MOLECULAR dynamics, *NANOMECHANICS, *RAREFIED gas dynamics flow, *FLOW velocity, *TEMPERATURE, *GAS flow, *THERMAL properties of gases, *DENSITY
Abstract

Purpose – The purpose of this paper is to investigate the gas flow characteristics in near wall region and the velocity slip phenomenon on the wall in nano-channels based on the molecular dynamics simulation. Design/methodology/approach – An external gravity force was employed to drive the flow. The density and velocity profiles across the channel, and the velocity slip on the wall were studied, considering different gas temperatures and gas-solid interaction strengths. Findings – The simulation results demonstrate that a single layer of gas molecules is adsorbed on wall surface. The density of adsorption layer increases with the decrease of gas temperature and with increase of interaction strength. The near wall region extents several molecular diameters away from the wall. The density profile is flatter at higher temperature and the velocity profile has the traditional parabolic shape. The velocity slip on the wall increases with the increase of temperature and with decrease of interaction strength linearly. The average velocity decreases with the increase of gas-solid interaction strength. Originality/value – This research presents gas flow characteristics in near wall region and the velocity slip phenomenon on the wall in nano-channels. Some interesting results in nano-scale channels are obtained. [ABSTRACT FROM AUTHOR]

Published
2014
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