نتایج جستجو برای: knudsen number kn

تعداد نتایج: 1172734  

2003
Jae Hyun Park Ali Beskok

A complete mathematical description of oscillatory Couette flows within the framework of kinetic theory is not available in the literature. Motivated by this and their vast engineering applications, we present a parametric study of time-periodic oscillatory Couette flows using the unsteady direct simulation Monte Carlo ~DSMC! method. Computations are performed as a function of the Knudsen ~Kn! ...

2011
J. Ghazanfarian A. Abbassi

In this reply to the Comment by Li-Shi Luo, we discuss the results of the lattice Bhatnagar-Gross-Krook (LBGK) model for high-Knudsen-number (Kn) flow and heat transfer, in the range of Kn 1. We present various studies employing the LBGK model for high-Kn flow and heat transfer simulations. It is concluded that, with the use of the LBGK model in the thermal lattice Boltzmann method for Kn 0.8, ...

2002
Nicolas G. Hadjiconstantinou Olga Simek

We investigate the constant-wall-temperature convective heat-transfer characteristics of a model gaseous flow in two-dimensional micro and nano-channels under hydrodynamically and thermally fully developed conditions. Our investigation covers both the slip-flow regime 0<Kn<0.1, and most of the transition regime 0.1,Kn<10, where Kn, the Knudsen number, is defined as the ratio between the molecul...

2004
S. Ansumali I. V. Karlin C. E. Frouzakis K. B. Boulouchos

A new method for the computation of flows at the micrometer scale is presented. It is based on the recently introduced minimal entropic kinetic models. Both the thermal and isothermal families of minimal models are presented, and the simplest isothermal entropic lattice Bhatnagar-Gross-Krook (ELBGK) is studied in detail in order to quantify its relevance for microflow simulations. ELBGK is equi...

2007

Traditionally, acoustics is concerned with the treatment of the fluid as a continuum using macroscopic quantities such as velocity and pressure as dependent variables. However, the continuum model breaks down for Knudsen numbers (Kn) greater than roughly 0.05, where Kn is defined as the ratio of mean free path to wavelength. Particle methods are necessary for, but not limited to, problems with ...

Journal: :transport phenomena in nano and micro scales 2015
y. bakhshan a. r. omidvar

micro scale gas flows has attracted significant research interest in the last two decades. in this research, the fluid flow of gases in the stepped micro-channel at a wide range of knudsen number has been analyzed with using the lattice boltzmann (mrt) method. in the model, a modified second-order slip boundary condition and a bosanquet-type effective viscosity are used to consider the velocity...

A. R. Omidvar Y. Bakhshan

  Micro scale gas flows has attracted significant research interest in the last two decades. In this research, the fluid flow of gases in the stepped micro-channel at a wide range of Knudsen number has been analyzed with using the Lattice Boltzmann (MRT) method. In the model, a modified second-order slip boundary condition and a Bosanquet-type effective viscosity are used to consider the veloci...

2015
Victor E. Ambruş Victor Sofonea

The Laguerre Lattice Boltzmann (LLB) models are constructed to exactly recover integrals of the equilibrium distribution function over octants of the momentum space. In the mesoscopic formulation of the Boltzmann equation, such integrals are necessary for the implementation of diffuse reflection boundary conditions. In this paper, we consider two implementations of the force term in the LLB mod...

Journal: :journal of computational applied mechanics 0
ali ghorbanpour arani professor, faculty of mechanical engineering, university of kashan, kashan, iran saeed amir assistant of professor, faculty of mechanical engineering, university of kashan, kashan, iran abbas karamali ravandia ms graduate, faculty of mechanical engineering, university of kashan, kashan, iran

in this study, nonlocal nonlinear instability and the vibration of a double carbon nanotube (cnt) system have been investigated. the visco-pasternak model is used to simulate the elastic medium between nanotubes, on which the effect of the spring, shear and damping of the elastic medium is considered. both of the cnts convey a viscose fluid and a uniform longitudinal magnetic field is applied t...

ثقفیان, محسن, رجبی, رمضان,

In this paper, viscous dissipation and roughness effects on heat transfer and fluid flow are investigated in microchannels using perturbation method in slip flow regime. The flow is considered to be laminar, developing thermally and hydrodynamically, two-dimensional, incompressible and steady-state. The working fluid is air, flowing between two parallel plates. The equations obtained from devel...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید