Numerical simulation of gas-phonon coupling in thermal transpiration flows

Numerical simulation of gas-phonon coupling in thermal transpiration flows.

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...

Hightemp Technique of High Temperature Gas Flows Numerical Simulation

A brief description of effective Navier-Stokes (NS) numerical technique for high temperature gas flows simulation (HIGHTEMP) is given. The NS codes have been developed for various gas-phase models from perfect gas to thermally and chemically nonequilibrium multicomponent and multitemperature gas medium. Slip effects, finite rate energy exchanges, surface catalysis and ablation can be taken into...

Numerical Simulation of Supersonic Gas Jet Flows and Acoustics Fields

Modeling of Thermal Transpiration Flows for Knudsen Compressor Optimization

Rarefied gas flows through two-dimensional finite length capillaries are studied numerically with the goal of performance optimization of a nanomembrane-based Knudsen compressor. Both density and temperature gradient driven flows are considered in a wide range of Knudsen numbers from 0.05 to 75. The length-to-height ratios from 5 to 30 were examined. Three different wall temperature distributio...

numerical simulation of downslope flows in a confined stratified region

geophysical fluids such as atmosphere and ocean often have stable density stratification; hence internal gravity waves are generated and propagated through them which are important in momentum and energy transfer in these media. these waves are also believed to generate layered structures in such media. recently there have been numerous theoretical, experimental and numerical studies on the way...