Title: Second law analysis of micro/nano Couette flow using direct simulation Monte Carlo method
Authors: Javad Abolfazli Esfahani; Omid Ejtehadi; Ehsan Roohi
Addresses: Centre of Excellence on Modelling and Control Systems & Department of Mechanical Engineering, Ferdowsi University of Mashhad, P.O. Box 91775-111, Mashhad, Iran ' Faculty of Engineering, Department of Mechanical Engineering, Ferdowsi University of Mashhad, P.O. Box 91775-111, Mashhad, Iran ' Faculty of Engineering, Department of Mechanical Engineering, Ferdowsi University of Mashhad, P.O. Box 91775-111, Mashhad, Iran
Abstract: In this paper, micro-/nano-Couette flow is considered with a special focus on entropy and entropy generation rate in the framework of the entropy transport equation using direct simulation Monte Carlo (DSMC) method. To investigate the entropy generation behaviour, three different models, i.e., equilibrium thermodynamics-base (ETB), non-equilibrium thermodynamics-base (NETB) and a proposed 'combined model', are applied and the ranges of validity of the employed models are discussed. Effects of compressibility and rarefaction on entropy and entropy generation behaviours are investigated. We also suggest 'specific entropy generation' as a tool for detecting non-equilibrium regions including Knudsen layer.
Keywords: DSMC; direct simulation; Monte Carlo simulation; micro/nano-Couette flow; entropy transport equations; entropy generation; Knudsen layer; continuum breakdown; nanotechnology; nanodevices.
International Journal of Exergy, 2013 Vol.13 No.3, pp.320 - 342
Received: 23 Jul 2012
Accepted: 14 Oct 2012
Published online: 27 Oct 2013 *