The interaction of a diffusing outgas flow from a sphere nose opposing a hypersonic free stream is studied numerically using the direct simulation Monte-Carlo technique under the transitional rarefied-gas-flow regime conditions at Knudsen numbers from 0.016 to 1.5 and blowing factors from 0.15 to 1.5. Strong influences of the blowing factor (the ratio of outgas mass flux to upstream mass flux) ...

Knudsen and Berson have applied truncated differential attack on 5 round SAFER K-64 successfully. However, their attack is not efficient when applied on 5 round SAFER SK-64 (with the modified key schedule) and can not be applied on 6 round SAFER. In this paper, we improve the truncated differential attack on SAFER by using better truncated differential and additional filtering method. Our attac...

We propose the rarefied-gas-cushion model (r-GCM), as an extended version of the gas-cushion model (GCM), to estimate the apparent slip of water flowing over a gas layer trapped at a solid surface. Nanobubbles or gas nanofilms may manifest rarefied-gas effects and the r-GCM incorporates kinetic boundary conditions for the gas component in the slip Knudsen regime. These enable an apparent hydrod...

The sheared granular flow of rough inelastic granular disks is analyzed in the high Knudsen number limit, where the frequency of particle-wall collisions is large compared with particle-particle collisions, using a kinetic theory approach. An asymptotic expansion is used in the small parameter epsilon =(nsigmaL), which is the ratio of the frequencies of particle-particle and particle-wall colli...

Based on the Boltzmann-BGK (Bhatnagar-Gross-Krook) equation, in this paper a discrete unified gas kinetic scheme (DUGKS) is developed for low-speed isothermal flows. The DUGKS is a finite-volume scheme with the discretization of particle velocity space. After the introduction of two auxiliary distribution functions with the inclusion of collision effect, the DUGKS becomes a fully explicit schem...

Aerosol particle reactions with vapor molecules and molecular clusters are often collision rate limited, hence determination of particle-vapor molecule and particle-molecular cluster collision rates are of fundamental importance. These collisions typically occur in the mass transfer transition regime, wherein the collision kernel (collision rate coefficient) is dependent upon the diffusive Knud...

Models for the individual steps used to fabricate integrated circuits (ICs) are of interest in order to improve fabrication efficiency and improve process designs. Here we focus on deposition from the gas stream, in which the dominant species is an inert carrier gas, as it flows across a wafer on which ICs are being fabricated. We model the transport of gaseous species to the surface and hetero...