Discussion Forum

Hi Fatu Viorel,

I have got the same problem as yours. Do you have an idea about the property Llimitfivar or luckily have already solved it? Could you please explain it to me? Thanks a lot!

Yuhong

Hi,

I haven't solve it but there seems to be a problem with the fluid flow in porous media: I've tried to make turbulent porous media flow and it didn't work.

My geometry is something like 10 rectangles one above the other. In the first rectangle i have low Re k-epsilon turbulence coupled with heat transfer and transport of diluted species, in the above rectangle i have porous media flow coupled with heat transfer and transport of diluted species and the above again low Re.... and so on.

I'm simulating the air flow in a solar dryer for fruits (the porous media). The air is flowing only due to density gradient (free convection). Coupled with the heat loss due to evaporation of water from fruits and with the moisture taken from fruits.

Try (if you have a similar case) not to make the porous media flow turbulent (i haven't try it yet - didn't had the time - yesterday I've posted the message)

If i find something new I'll let you know

Good luck,
Viorel

Hi,

Thanks for your reply. In my model, the error appears when I set lower limits for some of dependent variables in segregated study. One of modules is the transport of concentrated species which has three components. But actually two mass fractions are solved and the other one is calculated by 1-w1-w2, whose lower limit cannot be set. So when I move the mass faction w3, the third component out the setting colume, the error disappears. So I guess maybe the problem comes up from some variable cannot being set limit. Do you have any such variables in your model?

Hope this can help you!

Good luck!
Yuhong

Hi,

I'm new to Comsol 5.1 version and i have a problem with my simulation.

Does anybody know what "Llimitfivar" is? I'm searching for it's meaning for some time and i can't find anything. I have no idea what i'm doing wrong because when i hit the solve button it gives me thie error:
"Invalid field variable in property Llimitfivar"

I'm using moist air as a material

Hi Fatu,

as said in an another discussion of this forum (www.comsol.com/community/forums/cfd/thread/27967/), try to add a new study and delete the study you are using. Maybe it will work.

Hope it helps

Hi,

the problem apear when you change something in the physics node, but not in the study sequence node. For example, if you have a trubulent flow with kappa-omega turbulent model and deciede to take a new one, let's say kappa-epsilon turbulent model. In this case you have just to change the model with one click in the turbulence model type, but the lower limit in the study node will still try to solve for omega and not for epsilon. So in the case you have changed something in the physics, take new study or adapt the old one to the new problem. I hope my example will help you to find the mistake.

Best regards,
Antoni