Several algorithmic extensions to the Lattice Boltzmann method (LBM) that permits its application to rarefied gas flows are presented. The accuracy of the new method is first demonstrated by validating the desired power-law viscosity-temperature relationship over the range of power-law exponents typically found in single component fluids. Next, the plane Poiseuille flow scenario is simulated fo...

A complete set of boundary conditions for Grad’s 13 moment equations is derived from Maxwell’s boundary conditions for the Boltzmann equation. The equations are solved for plane Couette flow. The results exhibit temperature jump and slip, and agree well with DSMC calculations for Knudsen numbers Kn ≤ 0.1. Nonlinear effects lead to unphysical results at larger Knudsen numbers, and for very fast ...

mixed convection of al 2 o 3 -water nanofluid in a square microcavity is investigated numerically. governing equations are discretized and solved using the finite volume method and simpler algorithm. the knudsen number is selected between 0.001 and 0.1 to consider slip velocity and the jump temperature boundary conditions. results showed that nusselt number is a function of richardson number, k...

In the present work, effect of von Karman geometric nonlinearity on the vibration characteristics of a Y-shaped single walled carbon nanotube (Y-SWCNT) conveying viscose fluid is investigated based on Euler Bernoulli beam (EBB) model. The Y-SWCNT is also subjected to a longitudinal magnetic field which produces Lorentz force in transverse direction. In order to consider the small scale effects,...

We consider the evolution equations for bulk viscous pressure, diffusion current and shear tensor derived within second-order relativistic dissipative hydrodynamics from kinetic theory. By matching higher order moments directly to quantities, all terms which are of second in Knudsen number Kn vanish, leaving only $\mathcal{O}(\textrm{Re}^{-1} \textrm{Kn})$ $\mathcal{O}(\textrm{Re}^{-2})$ relaxa...

For gas flows in microfluidic configurations, the Knudsen layer close to the wall can comprise a substantial part of the entire flowfield and has a major effect on quantities such as the mass flow rate through micro devices. The Knudsen layer itself is characterized by a highly nonlinear relationship between the viscous stress and the strain rate of the gas, so even if the Navier-Stokes equatio...

Based on the Wigner function in local equilibrium, we derive hydrodynamical quantities for a system of polarized spin-1/2 particles: particle number current density, energy-momentum tensor, spin and dipole moment tensor. Comparing with ideal hydrodynamics without spin, additional terms at first second order Knudsen $\text{Kn}$ average polarization $\chi_s$ have been derived. The can be expresse...

Due to its intrinsically kinetic nature, lattice Boltzmann (LB) approach to simulating non-equilibrium gas flows has recently attracted significant research interest. Compared with other kinetic methods, it can offer a significantly smaller computational cost. To capture the nonlinear high-order rarefaction phenomena in gas flows, a geometry-dependent gas local mean free path has been proposed ...

Rarefied gas flows in thin film slider bearings are studied in a wide range of Knudsen numbers (Kn) at low Mach number (Ma) with the objective of developing simple physics-based semi-analytical models. A recently developed modified slip boundary condition for steady plane Couette flows and a generalized high-order velocity slip boundary condition, developed and validated earlier for pressure-dr...

Laser induced thermal desorption of Xe atoms into vacuum from a metal surface following the nano-second pulsed laser heating was investigated by the time-of-flight (TOF) measurement. The desorption flow was studied at a wide range of desorption flux by varying the initially prepared Xe coverage Θ (1 ML = 4.5 × 10(18) atoms/m(2)). At Θ = 0.3 ML, the TOF of Xe was well represented by a Maxwell-Bo...