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Assigning Materials
Posted Jan 25, 2013, 4:58 a.m. EST Fluid & Heat, Heat Transfer & Phase Change, Computational Fluid Dynamics (CFD), Geometry Version 4.3a 6 Replies
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Normally the red cros means that some material properties, expected by the physics seleted, are missing, but sometimes, it can also be red because the material is not yet set into the correct physics mode
An example: NITF conjugated heat flow with solid and fluid domains: by default COMSOL is se up for "solids", and no fluids domains are selected, if you add some metal and some wate rmaterial, COMSOL is still assuming that the physics are for all solid materials, but in the water material definitions you do not have Young modulus, Poisson etc, as these have no meaning for a fluid. The red cross will disappear from the moment you select the default NITF Fluid node and define that the water domain is a fluid, then the red cross are gone)
So, if your physics is set up correctly and the red cross is still there => check carefully the maerial properties missing, either you knw what to define, or it looks like some non-sens, then check your domain and BC selections and search for the error
--
Good luck
Ivar
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Hi
Normally the red cros means that some material properties, expected by the physics seleted, are missing, but sometimes, it can also be red because the material is not yet set into the correct physics mode
An example: NITF conjugated heat flow with solid and fluid domains: by default COMSOL is se up for "solids", and no fluids domains are selected, if you add some metal and some wate rmaterial, COMSOL is still assuming that the physics are for all solid materials, but in the water material definitions you do not have Young modulus, Poisson etc, as these have no meaning for a fluid. The red cross will disappear from the moment you select the default NITF Fluid node and define that the water domain is a fluid, then the red cross are gone)
So, if your physics is set up correctly and the red cross is still there => check carefully the maerial properties missing, either you knw what to define, or it looks like some non-sens, then check your domain and BC selections and search for the error
--
Good luck
Ivar
Thank you for nice explanation sir...
Can I use Brick and Concrete for heat transfer from water flowing through pipes in NITF model?? I can observe that some properties of Brick and Concrete like Dynamic Viscosity, Heat Capacity at Constant Pressure, Ratio of Specific Heats and Thermal Conductivity are not given in the COMSOL material library data. Can I assign t=values of my own for them??
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the material dtabase contains common values, if you look carefully you will even find some with T or pA temperature and absolute pressure dependence. The idea is that each users control that these values correspond to the need, partcularly state of the material, as fluid conctrete is certainly much different from solid dried concrete ;)
On some material parameters in the DB you have different states. If you have the maerial library you will fin dozen of similar material in different heat treated states ...
--
Good luck
Ivar
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Hi
the material dtabase contains common values, if you look carefully you will even ind some with T or pA temperature and pressure dependence. The idea is that each users control that these values correspond to the need, partcularly state of the material, as fluid conctrete is certainly much different from solid dried concrete ;)
On some maetrial parameters in the DB you have different states. If you have the maerial library you will fin dozen of similar material in different heat treated states ...
--
Good luck
Ivar
Okay, so can I take it that the values that are left blank for Concrete and Brick can be entered based upon my convenience (As I need the parameters that concern with solid concrete which has set already.) And, the same doubt for brick as with concrete.
Thank You..
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Once the material datab base loaded into your model, you can modify these, add remove at will, you can even ave your materials into your own data base, but check where you save it, if it's in ... user ... /.comsol they might disappear if you upgrade or reinstall COMSOl, as the directory .comsol might be deleted
--
Good luck
Ivar
Please login with a confirmed email address before reporting spam
Hi
Once the material datab base loaded into your model, you can modify these, add remove at will, you can even ave your materials into your own data base, but check where you save it, if it's in ... user ... /.comsol they might disappear if you upgrade or reinstall COMSOl, as the directory .comsol might be deleted
--
Good luck
Ivar
Thank You Ivar...
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