scispace - formally typeset
Search or ask a question
Book ChapterDOI

Molecular Dynamics and Monte Carlo Simulations for Heat Transfer in Micro and Nano-channels

01 Jan 2006-Vol. 4, Iss: 3, pp 661-666
TL;DR: In this article, a dense gas in micro and nano-channels is modelled by molecular dynamics and Monte Carlo simulations, and it is shown that in the limit situation both methods yield the same solution.
Abstract: There is a tendency to cool mechanical and electrical components by microchannels. When the channel size decreases, the continuum approach starts to fail and particle based methods should be used. In this paper, a dense gas in micro and nano-channels is modelled by molecular dynamics and Monte Carlo simulations. It is shown that in the limit situation both methods yield the same solution. Molecular dynamics is an accurate but computational expensive method. The Monte Carlo method is more efficient, but is less accurate near the boundaries. Therefore a new coupling algorithm for molecular dynamics and Monte Carlo is introduced in which the advantages of both methods are used.

Content maybe subject to copyright    Report

Citations
More filters
Journal ArticleDOI
Qibin Li1, Chao Liu1
TL;DR: In this paper, nonequilibrium molecular dynamics simulation is employed to investigate the thermal properties of fluid confined in different FCC nanochannels and the results show that fluid in different lattice channels appears diverse wetting characteristics at low temperature.

45 citations

Journal ArticleDOI
TL;DR: In this paper, a review of the literature on gas microconvection in the single-phase continuum regime is presented, which reveals that gas microflow characteristics significantly differ from those in the conventionally sized channels.
Abstract: Gas microconvection is a strategic research area in transport phenomena since it is the basis for a wide range of miniaturized high-performance applications like microelectromechanical systems. The literature reveals that in the single-phase continuum regime, microconvection characteristics significantly differ from those in the conventionally sized channels. Deviations from the expected behavior have been attributed to scaling effects that surface at the microscale. For most gas microflow applications that are in the slip or early transition regimes, the analysis is further complicated by rarefaction and compressibility effects. Therefore, microslip flows are comprehensively reviewed to identify the implications of reported findings with respect to the validity of continuum-based models. Based on the synthesis of studies, the need to better demark the continuum and free-molecular flow regimes is revealed, which necessitates the identification of important nonrarefaction scaling effects. This would enable the computationally inexpensive continuum models to be extended to higher Knudsen numbers. The analyses suggest that early transition regime behavior is characterized more by conjugate nonrarefaction scaling effects and higher order slip boundary conditions than purely by rarefaction.

30 citations

Journal ArticleDOI
Chenglong Zhang1, Guofei Shen1, Chengxiang Li1, Wei Ge1, Jinghai Li1 
TL;DR: In this paper, a pseudo-particle model is combined with a hard-sphere model to simulate flows and transport processes at high Knudsen numbers without losing necessary molecular details in describing their macro-scale behaviors.
Abstract: Continuum methods are not accurate enough for flows at high Knudsen numbers, whereas rigorous molecular dynamics (MD) methods are too costly for simulations at practical dimensions. Hard-sphere (HS) model is a simplified MD method efficient for dilute gaseous flow but is of poor parallelism due to its event-driven nature, which sets a strong limitation to its large-scale applications. In this work, pseudo-particle modelling, a time-driven modelling approach is coupled with HS model to construct a scalable parallel method capable of simulating flows and transport processes at high Knudsen numbers without losing necessary molecular details in describing their macro-scale behaviours. The method is validated in several classical simulation cases and its performance is evaluated to be favourable. To demonstrate the potential applications of this method, we also simulate the diffusion of small molecules in multi-scale porous media which is related to catalysis, material preparation and micro chemical en...

12 citations

Journal ArticleDOI
TL;DR: A mathematical model has been developed to characterize the density oscillations as the result of packing of molecules in case of a dense gas near the micro and nano-channels walls, and the height and the position of thedensity oscillation peaks near the wall are characterized.

11 citations

References
More filters
Book
11 Feb 1988
TL;DR: In this paper, the gear predictor -corrector is used to calculate forces and torques in a non-equilibrium molecular dynamics simulation using Monte Carlo methods. But it is not suitable for the gear prediction problem.
Abstract: Introduction Statistical mechanics Molecular dynamics Monte Carlo methods Some tricks of the trade How to analyse the results Advanced simulation techniques Non-equilibrium molecular dynamics Brownian dynamics Quantum simulations Some applications Appendix A: Computers and computer simulation Appendix B: Reduced units Appendix C: Calculation of forces and torques Appendix D: Fourier transforms Appendix E: The gear predictor - corrector Appendix F: Programs on microfiche Appendix G: Random numbers References Index.

21,073 citations

Book
16 Jun 1994
TL;DR: The direct simulation Monte Carlo (or DSMC) method has, in recent years, become widely used in engineering and scientific studies of gas flows that involve low densities or very small physical dimensions as mentioned in this paper.
Abstract: The direct simulation Monte Carlo (or DSMC) method has, in recent years, become widely used in engineering and scientific studies of gas flows that involve low densities or very small physical dimensions. This method is a direct physical simulation of the motion of representative molecules, rather than a numerical solution of the equations that provide a mathematical model of the flow. These computations are no longer expensive and the period since the 1976 publication of the original Molecular Gas Dynamics has seen enormous improvements in the molecular models, the procedures, and the implementation strategies for the DSMC method. The molecular theory of gas flows is developed from first principles and is extended to cover the new models and procedures. Note: The disk that originally came with this book is no longer available. However, the same information is available from the author's website (http://gab.com.au/)

5,311 citations

Journal ArticleDOI
TL;DR: In this article, the limit of the random empirical measures associated with the Bird algorithm is shown to be a deterministic measure-valued function satisfying an equation close (in a certain sense) to the Boltzmann equation.
Abstract: Bird's direct simulation Monte Carlo method for the Boltzmann equation is considered. The limit (as the number of particles tends to infinity) of the random empirical measures associated with the Bird algorithm is shown to be a deterministic measure-valued function satisfying an equation close (in a certain sense) to the Boltzmann equation. A Markov jump process is introduced, which is related to Bird's collision simulation procedure via a random time transformation. Convergence is established for the Markov process and the random time transformation. These results, together with some general properties concerning the convergence of random measures, make it possible to characterize the limiting behavior of the Bird algorithm.

476 citations

Journal ArticleDOI
TL;DR: In this article, numerical simulation of the hydrodynamics of gas flow and fluid flow using the Direct Simulation Monte Carlo method is described, and the method is applied to both gas and fluid flows.
Abstract: Numerical simulation of the hydrodynamics of gas flow and fluid flow is described using the Direct Simulation Monte Carlo method. (AIP) © 1997 American Institute of Physics.

217 citations

Journal ArticleDOI
TL;DR: The historical background of refrigeration from its use in the early 1800s to its implementation in computer systems in the late 1990s is reviewed and the advantages have outweighed the disadvantages, leading to the first use by IBM ofrigeration in cooling the S/390 G4 server.
Abstract: The IBM S/390® G4 CMOS system, first shipped in 1997, was the first high-end system to use refrigeration. The decision to employ refrigeration cooling instead of other cooling options such as high-flow air cooling or various water-cooling schemes focused on the potential system performance improvement obtainable by lowering coolant temperatures using a refrigeration system. This paper reviews the historical background of refrigeration from its use in the early 1800s to its implementation in computer systems in the early 1990s. The advantages and disadvantages of using refrigeration in the cooling of computer systems are examined. The advantages have outweighed the disadvantages, leading to the first use by IBM of refrigeration in cooling the S/390 G4 server. The design of the refrigeration system for the S/390 G4 system is described in detail, and some of the key parametric studies that contributed to the final design are described.

131 citations