Thermal transpiration is a rarefied gas flow driven by a wall temperature gradient and is a promising mechanism for gas pumping without moving parts, known as the Knudsen pump. Obtaining temperature measurements along capillary walls in a Knudsen pump is difficult due to extremely small length scales. Meanwhile, simplified analytical models are not applicable under the practical operating condi...

This paper presents a numerical investigation for laminar forced convection flow of a radiating gas in a rectangular duct with a solid element that makes a backward facing step. The fluid is treated as a gray, absorbing, emitting and scattering medium. The governing differential equations consisting the continuity, momentum and energy are solved numerically by the computational fluid dynamics t...

In the present study, a visual experimental system was built to explore multiphase hydrodynamic features in underwater launching process. The whole processes of gas-curtain generation produced by multichannel jet convergence, expansion, and projectile movement were captured using direct photography. results show that as area single groove grows from 6.25 mm2 11.25 mm2, displacement 47.5%, proje...

effective methodologies for efficient preparation of semicarbazones from aldehydes or ketones via milling and the subsequent regeneration of the parent carbonyls by gaseous nitrogen dioxide are described under solid-solid and gas-solid reaction conditions, respectively. these methods are fast, simple and environmentally benign which do not require the use of any auxiliaries such as catalysts or...

A gas is said to physisorb onto the surface of a solid if the net interaction between a gas particle and the solid is accounted for by an effective surface potential, V, (r), the long-range part of which is essentially the interaction energy between the mutually induced fluctuating dipole moments in the adparticle and in the solid. The strong short-range repulsion is largely due to increasing c...

n this work, computational fluid dynamics of the flow behavior in a cold flow of fluidized bed is studied. An improved finite volume based finite element method has been introduced to solve the two-phase gas/solid flow hydrodynamic equations. This method uses a collocated grid, where all variables are located at the nodal points. The fluid dynamic model for gas/solid two-phase flow is based on ...

By definition, solid state is that particular aggregation form of matter characterized by strong interaction forces between constituent particles (atoms, ions, or molecules). As a result, a solid state material has an independent geometric form (in contrast to liquids, which take the form of the container) and an invariant volume (in contrast to gases/vapors) in given temperature and pressure c...

Following almost ten years of incubation, solid state radiation detectors have, in recent years, achieved increasing emphasis and use in low energy nuclear physics.1-4 Such detectors depend on the production of free-charge carriers in crystals by the interaction of incident particles with bound electrons. Solid-state detectors are analogues of the well-known gaseous ionization chamber. In an io...

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. f a b s t r a c t We present a simple numerical method to simulate the interaction of two non-miscible compressible materials separated by an interface. The media considered may have significantly different physical properties and constitutive l...