|September 19, 2011, 11:38||
density gradient driven mass flows in gases
Join Date: Mar 2009
Posts: 159Rep Power: 10
I am struggling to understand how the following problem can be stated within the two-species species Navier-Stokes equations with diffusion.
The following is an incompressible, low-pressure gas flow in the hydrodynamic regime.
Consider a long thin tube, left half filled with a light gas (hydrogen, helium), the right half with a heavy gas (Argon, Xenon). The two halves are separated by a barrier. Gases are at same temperature and pressure.
At time t=0, we remove the barrier, and the gases start diffusing. Since the light gas is diffusing in to the heavy gas, and the other way around, there is a mass flow from the right to the left.
I can derive diffusion driven mass flow the diffusion equations. How do I couple that with the Navier Stokes equation?
Momentum transfer is handled by the Navier-Stokes equations. But the NS equations only have external forces and the pressure gradient as the driving term. Is the diffusion the external forcing term?
What am I missing?
|Thread||Thread Starter||Forum||Replies||Last Post|
|Density of air for calculating the mass flow rate from Darcy's law||Hermano||Main CFD Forum||0||August 22, 2011 11:17|
|Specifying vertical density gradient in FLUENT||ajagan||FLUENT||0||August 18, 2011 22:16|
|lid driven turbulent flows||student||Main CFD Forum||0||July 20, 2007 12:43|
|Pressure correction in Buoyancy driven flows||Aditya||Main CFD Forum||0||March 8, 2007 07:36|
|Multiphase, Bubbly flows, Virtual Mass||KP||Main CFD Forum||2||July 18, 2005 10:46|