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-   -   Setting viscosities in Interior zones (http://www.cfd-online.com/Forums/fluent/37806-setting-viscosities-interior-zones.html)

philip September 6, 2005 14:47

Setting viscosities in Interior zones
 
Importing a .Neu file into Gambit, setting the boundary conditions and 3 continuum fluid conditions, then exporting the msh to fluent.

In Fluent he continuum conditions i set seem to only aplly to the faces but not in between (density and viscosities). The zones that have the interior option don't seem to have any way to set the viscosity.

Any ideas on what I should be doing?

joshi September 6, 2005 15:41

Re: Setting viscosities in Interior zones
 
Interiors zones will take values for density and viscosity from the fluid property assigned in the Materials panel in Fluent

philip September 6, 2005 21:19

Re: Setting viscosities in Interior zones
 
but how do you select wich materials to use for the interior zones? for fluid i can press 'set' and set the fluid but not for interior.

Masood September 7, 2005 14:41

Re: Setting viscosities in Interior zones
 
hi how can u change or mention the fluid properties urself. tht shpuld be claculated. like density and temprature changes in combuston or heat transfer etc.


philip September 8, 2005 10:21

Re: Setting viscosities in Interior zones
 
I'm trying to model specific materials, doing so by changing the viscocity. I'm only modeling the flow, no heat transfer or reactions are taking place.

basically I have 3 pieces that fill a box, and i want them to have different viscosities as there is a pressure gradient between one face of the box and another.

Masood September 12, 2005 13:12

Re: Setting viscosities in Interior zones
 
hi take it physically. how can u mention viscosity of diffrent materials in a same box. if fluid is passing through diffrent materials u can specify diffrent porosity of material but how can viscosity.


philip September 14, 2005 12:06

Re: Setting viscosities in Interior zones
 
well thats what in effect I am trying to do. I have a sphere like shape in the middle of a box, i want the fluid to flow slower thru the sphere (higher viscoistiy or lower porousity?) I have been trying to use porous jump for this purpose but no such luck. any suggestions?

Masood September 14, 2005 14:27

Re: Setting viscosities in Interior zones
 
hi a ball of porous material in fluid. isnt it done like tht first define a volume for fluid zone. then defien a sphere at the desired loc. split the fluid volume with the sphere so u have 2 connected volumes. now when defining zones define sphere as porous zone. and fluid as fluid. which will be just like a porous ball in fluid. tell me if i am right. good luck...


philip September 16, 2005 14:07

Re: Setting viscosities in Interior zones
 
I can't do boolean operation like split in gambit, it's imported as a NEU file so it has all virtual geometry. however the volumes are seperated. i set the face(s) between them to be porous zone and the volume inside the sphere to be porous zone. I can't get iterate all he backflow though, the solution it gives doesn't seem to be right either.

Do you know how to adjust the face permeability (default is 1e+10) for the porous jump so that the fluid flows faster thru the sphere so that i might see better results?


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