[baechtel]

Hi everybody,

I want to implement a new fluid on fluent. I need to put the viscosity (value=x), the surface tension (value=y) and the density (value=z) and maybe the viscosity law from blood.
Is it possible to use the udf from FLuent ?

Or do you think it is the same to use the materials panel which allows me to use non-newtonian fluid and to change the physical properties ?

Thank you very much for answer,

Guillaume

[midoo]

hi friend,
your problem is very easy so dont worry, you go to 'Define' and then chose 'Materials'
a panel will open to caracterise your materials, so write 'blood' in name box then enter your own value of density and viscosity.
if you want to use a non-newtonian fluid you should change the viscosity from 'constant' to 'non-newtonian-power-law' in the list then you enter the differents parametres (k,n,T0,minimum viscosity and maximum viscosity) finaly one click on the 'change/create' boutton

be nice

[baechtel]

It is working well, thanks a lot

[saynovich]

Originally Posted by baechtel

It is working well, thanks a lot

Hi Baechtel,

Which values did you use for k,n,T0,minimum viscosity and maximum viscosity?

Thanks,

[Summer82]

Originally Posted by saynovich

Hi Baechtel,

Which values did you use for k,n,T0,minimum viscosity and maximum viscosity?

Thanks,

I have the same problem here, what values should I use for k,n,T0,minimum viscosity and maximum viscosity?

Thanx

[CeesH]

I'd guess there should be quite a lot of papers published on the rheology of blood? A 2-second google-scholar search for example gives an often cited review by Merrill (1969) and I'm quite sure there's more modern literature available as well. So really, google (scholar) or some other literature database is your friend here. Which values you need? I'd think about what you want to know. If there is a wide range of literature values reported, it may be worthwhile comparing the different models (provided you can validate the flow profile or so). Perhaps the viscosity differs between people with regular blood, people who take certain medicine (EPO increases red cell count, so likely viscosity) and people with certain diseases (I would think sickle cell anemia would lower blood viscosity for example?), so that may also be a point of interest.

So asking which parameters you need is the wrong question. You should ask yourself which conditions you want to simulate, and search for the proper parameters in literature. Can't find it? Then find yourself a knife and a rheometer