A new iterative wall heat flux specifying technique in DSMC for heating/cooling simulations of MEMS/NEMS

Akhlaghi, Hassan; Roohi, Ehsan; Stefanov, Stefan

doi:10.1016/j.ijthermalsci.2012.04.002

Cited by 56 publications

(31 citation statements)

References 38 publications

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“…However sometimes in practice it is important to be able to employ constant heat flux boundary conditions so that the heat exchange between the system and the surroundings can be controlled. The examples of the implementation of the heat flux boundary conditions are given in [26], [27] for the DSMC and kinetic approaches, respectively.…”

Section: Resultsmentioning

confidence: 99%

Continuum and Kinetic Simulations of Heat Transfer Trough Rarefied Gas in Annular and Planar Geometries in the Slip Regime

Hadj-Nacer

Maharjan

et al. 2017

Journal of Heat Transfer

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This version is available at https://strathprints.strath.ac.uk/60004/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. Continuum and kinetic simulations of Heat Transfer trough Rarefied Gas in Annular and Miles GreinerProfessor, ASME Fellow Mechanical Engineering Department University of Nevada, Reno Reno, Nevada, 89557 Email: greiner@unr.edu ABSTRACT Steady-state heat transfer through a rarefied gas confined between parallel plates or coaxial cylinders, whose surfaces are maintained at different temperatures is investigated using the non-linear Shakhov (S) model kinetic equation and DSMC technique in the slip regime. The profiles of heat flux and temperature are reported for different values of gas rarefaction parameter δ, ratios of hotter to cooler surface temperatures T , and inner to outer radii ratio R . The results of S-model kinetic equation and DSMC technique are compared to the numerical and analytical solutions of the Fourier equation subjected to the Lin & Willis temperature-jump boundary condition. The analytical expressions are derived for temperature and heat flux for both geometries with hotter and colder surfaces having different values of the thermal accommodation coefficient. The results of the comparison between the kinetic and continuum approaches showed that the Lin & Willis temperature-jump model accurately predicts heat flux and temperature profiles for small temperature ratio T = 1.1 and large radius ratios R ≥ 0.5, however, for large temperature ratio, a pronounced disagreement is observed.

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Section: Resultsmentioning

confidence: 99%

Continuum and Kinetic Simulations of Heat Transfer Trough Rarefied Gas in Annular and Planar Geometries in the Slip Regime

Hadj-Nacer

Maharjan

et al. 2017

Journal of Heat Transfer

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“…This is not so in Refs. [16,18], where adiabaticity is implemented by an iterative scheme that sets the local boundary temperature such that the local heat flux into the wall vanishes; as a result, one observes oscillation of heat flux on the walls. We emphasize that by following the methodology in the current study, as one sets a surface to be adiabatic by isotropic scattering, there is no need to prescribe any temperature for the wall.…”

Section: A Micro Lid Driven Cavitymentioning

confidence: 99%

“…Wang et al [16,17] introduced the inverse temperature sampling method to model the heat flux at the wall, and demonstrated that this method can correctly specify the heat flux at the surface. More recently, Akhlaghi et al [18] proposed an iterative technique to impose the heat flux boundary condition in DSMC. In their method, an estimate to the wall temperature is initially made.…”

Section: Introductionmentioning

confidence: 99%

DSMC and R13 modeling of the adiabatic surface

Mohammadzadeh

Rana

2016

International Journal of Thermal Sciences

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Adiabatic wall boundary conditions for rarefied gas flows are described with the isotropic scattering model. An appropriate sampling technique for the direct simulation Monte Carlo (DSMC) method is presented, and the corresponding macroscopic boundary equations for the regularized 13-moment system (R13) are obtained. DSMC simulation of a lid driven cavity shows slip at the wall, which, as a viscous effect, creates heat that enters the gas while there is no heat flux in the wall. Analysis with the macroscopic equations and their boundary conditions reveals that this heat flux is due to viscous slip heating, and is the product of slip velocity and shear stress at the adiabatic surface. DSMC simulations of the driven cavity with adiabatic walls are compared to R13 simulations, which both show this non-linear effect in good agreement for Kn < 0.3.

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“…34,35 In DSMC, the gas molecules are represented by so called DSMC parcels, with each parcel representing a large number N eq of real molecules. These parcels move and collide with each other in the simulated physical space.…”

Section: B Direct Simulation Monte Carlomentioning

confidence: 99%

Simulation of atomic layer deposition on nanoparticle agglomerates

Jin

Kleijn

Ommen

2016

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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Coated nanoparticles have many potential applications; production of large quantities is feasible by atomic layer deposition (ALD) on nanoparticles in a fluidized bed reactor. However, due to the cohesive interparticle forces, nanoparticles form large agglomerates, which influences the coating process. In order to study this influence, the authors have developed a novel computational modeling approach which incorporates (1) fully resolved agglomerates; (2) a self-limiting ALD half cycle reaction; and (3) gas diffusion in the rarefied regime modeled by direct simulation Monte Carlo. In the computational model, a preconstructed fractal agglomerate of up to 2048 spherical particles is exposed to precursor molecules that are introduced from the boundaries of the computational domain and react with the particle surfaces until these are fully saturated. With the computational model, the overall coating time for the nanoparticle agglomerate has been studied as a function of pressure, fractal dimension, and agglomerate size. Starting from the Gordon model for ALD coating within a cylindrical hole or trench [Gordon et al., Chem. Vap. Deposition 9, 73 (2003)], the authors also developed an analytic model for ALD coating of nanoparticles in fractal agglomerates. The predicted coating times from this analytic model agree well with the results from the computational model for Df = 2.5. The analytic model predicts that realistic agglomerates of O(109) nanoparticles require coating times that are 3–4 orders of magnitude larger than for a single particle.

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A new iterative wall heat flux specifying technique in DSMC for heating/cooling simulations of MEMS/NEMS

Cited by 56 publications

References 38 publications

Continuum and Kinetic Simulations of Heat Transfer Trough Rarefied Gas in Annular and Planar Geometries in the Slip Regime

Continuum and Kinetic Simulations of Heat Transfer Trough Rarefied Gas in Annular and Planar Geometries in the Slip Regime

DSMC and R13 modeling of the adiabatic surface

Simulation of atomic layer deposition on nanoparticle agglomerates

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