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Buoyancy Flow by Boussinesq Approximation
Posted 6 ott 2009, 04:05 GMT-4 0 Replies
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simulating buoyancy flow by aid of Boussinesq approximation I get problems by Fz. In my model there is a laminar navier stokes flow and a mass transfer of salt. density=f(c). I start simulation with a very high viscosity (for brine near water: 1e6 !!!) and a small effect of the Boussinesq approximation (gravfak=1e-4).
Fz=-9,81*gravfak*rhof(cc1,Tconst)
The axi-symetrical model has a fresh water inflow, a brine outflow and a wall with salt dissolution. You can see it in the attached file.
If I reduce viscosity I have to reduce the influence of buoyancy flow by reducing gravfak in the same manner. Cell-Reynold's number is <1, Cell-Peclet number is critical but not the problem.
I think the Boussinesq approximation causes the numerical problems. Is there anybody who has a good idea to modify the buoyancy flow ?
Working with -9,81*gravfak*(rhof(cc1,Tconst)-rho0) doesn't help.
Thank you very much!
Best regards
Michael R.
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Hello Michael Rembe
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