scholarly journals Slip boundary condition of heat flux in Knudsen layers

2014 ◽  
Vol 470 (2161) ◽  
pp. 20130578 ◽  
Author(s):  
Mingtian Xu
Keyword(s):  
Boundary Condition ◽  
Heat Flux ◽  
Velocity Slip ◽  
Slip Boundary Condition ◽  
Mean Free Path ◽  
Knudsen Layer ◽  
Boltzmann Transport ◽  
Slip Boundary ◽  
The Mean ◽  
Solid Walls

In a Knudsen layer with thickness comparable to the mean free path, collisions between heat carriers and solid walls play an important role in nanoscale heat transports. An interesting question is that whether these collisions also induce the slip of heat flow similar to the velocity slip condition of the rarefied gases on solid walls. In this work based on the discrete Boltzmann transport equation, the slip boundary condition of heat flux on solid walls in the Knudsen layer is established. This result is exemplified by the slip boundary condition of heat flux in nanowires, which has been proposed in a phenomenological way.

Numerical Simulation of Newtonian Fluid Flow in a T-Channel with no Slip/Slip Boundary Conditions on a Solid Wall

2017 ◽  
Vol 743 ◽  
pp. 480-485
Author(s):  
Evgeny Borzenko ◽  
Olga Dyakova
Keyword(s):  
Boundary Condition ◽  
Fluid Flow ◽  
Solid Wall ◽  
Simple Procedure ◽  
Slip Boundary Condition ◽  
Navier Slip ◽  
Slip Boundary ◽  
Pressure Profiles ◽  
Slip Yield Stress ◽  
Solid Walls

The planar flow of a Newtonian incompressible fluid in a T-shaped channel is investigated. Three fluid interaction models with solid walls are considered: no slip boundary condition, Navier slip boundary condition and slip boundary condition with slip yield stress. The fluid flow is provided by uniform pressure profiles at the boundary sections of the channel. The problem is numerically solved using a finite difference method based on the SIMPLE procedure. Characteristic flow regimes have been found for the described models of liquid interaction with solid walls. The estimation of the influence of the Reynolds number, pressure applied to the boundary sections and the parameters of these models on the flow pattern was performed. The criterial dependences describing main characteristics of the flow under conditions of the present work have been demonstrated.

Discrete hydrodynamics near solid walls: Non-Markovian effects and the slip boundary condition

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
D. Duque-Zumajo ◽  
J. A. de la Torre ◽  
Diego Camargo ◽  
Pep Español
Keyword(s):  
Boundary Condition ◽  
Slip Boundary Condition ◽  
Slip Boundary ◽  
Solid Walls

New slip boundary condition in high-speed rarefied gas flow simulations

2019 ◽  
Vol 234 (3) ◽  
pp. 840-856
Author(s):  
Nam TP Le ◽  
Nam H Tran ◽  
Thoai N Tran ◽  
Toan T Tran
Keyword(s):  
Boundary Condition ◽  
High Speed ◽  
Gas Flow ◽  
Rarefied Gas ◽  
Slip Boundary Condition ◽  
Mean Free Path ◽  
Slip Condition ◽  
Monte Carlo Data ◽  
Flow Simulations ◽  
Slip Boundary

In this paper, we propose a new slip boundary condition in hypersonic gas flow simulations. It is derived by considering the Langmuir isotherm adsorption into the Kaniadarkis et al. model of the kinetic theory of gas. Moreover, the motion of the adsorbed molecules over the surface (i.e. surface diffusion) is considered for the calculation of the mean free path in new slip condition. Three aerodynamic configurations are selected for evaluating new slip condition such as (1) the sharp-leading-edge flat plate, (2) circular cylinder in cross-flow, and (3) the sharp 25°–55° biconic cases. Hypersonic gas flows have the Mach number ranging from 6.1 to 15.6, and the working gases are argon and nitrogen. The simulation results show that new slip condition predicts better slip velocity than the Maxwell slip condition and gives good agreement with the direct simulation Monte-Carlo data for all cases considered in the present work.

Rarefied gas flow between parallel plates

1969 ◽  
Vol 66 (1) ◽  
pp. 189-196 ◽  
Author(s):  
M. M. R. Williams
Keyword(s):  
Boundary Condition ◽  
Integral Equation ◽  
Gas Flow ◽  
Rarefied Gas ◽  
Volumetric Flow Rate ◽  
Slip Boundary Condition ◽  
General Boundary Condition ◽  
Boltzmann Transport ◽  
Parallel Plates ◽  
Slip Boundary

AbstractThe flow of a rarefied gas between parallel plates has been studied via the linearized Boltzmann transport equation. Using a general boundary condition, which includes an arbitrary ratio of specular to diffuse reflection from the wall, we have derived an integral equation for the mass flow velocity. The integral equation is solved by using a replication property of the kernel and application of the method of Muskelishvili.The total volumetric flow rate is obtained and a slip boundary condition is deduced for use with the hydrodynamic equations.Certain aspects of the eigenvalue spectrum associated with the Boltzmann equation are discussed.

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