Results 281 to 290 of about 10,814,884 (348)

Gas Flow in Microchannels and Nanochannels With Variable Cross Section for All Knudsen and All Mach Number Values

, 2021
The analytical solution for steady viscous pressure-driven compressible isothermal gas flow through micro- and nanochannels with variable cross section for all Knudsen and all Mach number values is presented in this paper. The continuum one-dimensional
S. Milićev, N. Stevanovic
semanticscholar   +1 more source

The Effects of Geometry and Knudsen Numbers on Micro- and Nanochannel Flows

ASME 2011 9th International Conference on Nanochannels, Microchannels, and Minichannels, Volume 2, 2011
In this work we use a three dimensional Molecular Dynamics simulation method to study the effect of different geometries and Knudsen number regimes on the gas flow in micro-nanochannels. Argon molecules have been used for the simulations. Thermal wall and diffusive-specular wall types were used for the boundaries of the channels.
Kim, J.H., Frijns, A. J.H., Nedea, S. V., Van Steenhoven, A. A.   +3 more
openaire   +2 more sources

Approximating Collisional Freestream Attenuation at Transitional Knudsen Numbers

AIAA Journal, 1997
When a body such as an instrument package is immersed in a rarefied flowfield, the result is a distortion of the freestream. This perturbation is a stumbling block for code developers seeking reliable experimental data for comparison with flowfield predictors.
King, Lyon B., Gallimore, Alec D.
openaire   +1 more source

Photophoretic force on particles for low Knudsen number

Applied Optics, 1983
Calculations are presented for the photophoretic force on a spherical aerosol particle with size much larger than the mean free path of the surrounding gas molecules. Very good agreement is shown with recent experimental data. The results show that both components of the complex refractive index can be inferred from radiometric measurements.
openaire   +2 more sources

Flows at Large Knudsen Numbers

1969
Free-molecule flow is defined as the flow obtained in the limit when the Knudsen number Kn → ∞. In that case, the Boltzmann equation takes the form (see also §§2.11 and 4.2) $$ \frac{{df}}{{dt}} = \frac{{\partial f}}{{\partial t}} + \xi \cdot \frac{{\partial f}}{{\partial x}} + \frac{X}{m} \cdot \frac{{\partial f}}{{\partial \xi }} = 0 $$ (1.1)
openaire   +1 more source

Orifice flow at high Knudsen numbers

Journal of Fluid Mechanics, 1961
Several interesting features of the flow field in free-molecule flow through an orifice are discussed. An estimate is then made of the deviation of the mass flow $\dot{m}$ through the orifice from its limiting free-molecule value $\dot{m}$ for small departures from the limit. Using an iteration method proposed by Willis, it is shown that this deviation
openaire   +2 more sources

Brownian coagulation of aerosols at low Knudsen number

Faraday Symposia of the Chemical Society, 1973
Dibutyl phthalate aerosols of narrow size distribution have been prepared in a falling-film generator using nitrogen rather than helium as the carrier gas. The Knudsen number in nitrogen is considerably lower so that the Cunningham correction is much less.
Gilbert A. Nicolaon, Milton Kerker
openaire   +1 more source

Flows at Small Knudsen Numbers

1969
It was shown in Chapter III (see §§3.6–3.8) that, at internal points of the flow, the Hilbert—Enskog— Chapman expansion gives a solution which converges asymptotically to a solution of the Boltzmann equation for Knudsen numbers tending to zero. However, for an arbitrarily small Knudsen number, there is a region near the boundary in which that series is
openaire   +1 more source

Lubrication Theory at Arbitrary Knudsen Number

Journal of Tribology, 1985
It is demonstrated that the slip flow Reynolds equations for ultra low clearance gas bearings can be derived from kinetic theory by an approximation scheme appropriate for arbitrary Knudsen numbers. Thus the usefulness of the slip flow Reynolds equation is extended to cases where it would not be expected to hold.
openaire   +1 more source

Molecular velocity distribution at large Knudsen numbers

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 1991
It is commonly assumed that the distribution of molecular velocities follows a Maxwellian distribution also in the range of high and ultrahigh vacuum, i.e., at large Knudsen numbers. This distribution is theoretically derived from statistical analysis of an ensemble of molecules with frequent molecule–molecule collisions.
W. Jitschin, G. Reich
openaire   +1 more source