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-   -   simulation on cooling tower (http://www.cfd-online.com/Forums/floefd-floworks-flotherm/70705-simulation-cooling-tower.html)

kacee December 2, 2009 22:45

simulation on cooling tower
 
hi, everyone. now i handle a project about simulation on cooling tower, can i knw can i include the air humidity and make up rate so that my result more accuarate?

kacee December 4, 2009 02:48

can anyone told me tis isint a limitation.

murat December 6, 2009 17:50

Quote:

Originally Posted by kacee (Post 238573)
hi, everyone. now i handle a project about simulation on cooling tower, can i knw can i include the air humidity and make up rate so that my result more accuarate?

Yes you can include huminity while choosing fluid and it occurs more accuarate solutions

kacee December 12, 2009 02:07

Quote:

Originally Posted by murat (Post 238885)
Yes you can include huminity while choosing fluid and it occurs more accuarate solutions

when i choosing the fluid, i choosing air and water. how to include the humidity?

Boris_M December 12, 2009 09:20

No, don't use water, just use air and then there is the field below where you can also select High Machnumber option or laminar and turbulent. Here you can also find "humidity". The relative humidity can then be set in the initial settings in the wizard and in the boundary conditions for flow etc.

But if this makes your results more accurate is not certain, it depends on the kind of results you are interested in. You should also not add random things to make results correct, the boundary conditions you apply should mirror the reality. Using humidity when there is none in reality is not simulating the reality it would be making the results the way you want it to be.

kacee December 12, 2009 20:50

Quote:

Originally Posted by Boris_M (Post 239793)
No, don't use water, just use air and then there is the field below where you can also select High Machnumber option or laminar and turbulent. Here you can also find "humidity". The relative humidity can then be set in the initial settings in the wizard and in the boundary conditions for flow etc.

But if this makes your results more accurate is not certain, it depends on the kind of results you are interested in. You should also not add random things to make results correct, the boundary conditions you apply should mirror the reality. Using humidity when there is none in reality is not simulating the reality it would be making the results the way you want it to be.

thats mean at first i choose air as my fluid and i include the humidity then i choose sub domain as water?

Boris_M December 13, 2009 13:19

If there is no water at all except the humidity you won't need water as a fluid subdomain. It depends on the model and what you want to simulate. I don't know what is needed in you model without a description or pictures.

kacee December 14, 2009 05:21

Quote:

Originally Posted by Boris_M (Post 239862)
If there is no water at all except the humidity you won't need water as a fluid subdomain. It depends on the model and what you want to simulate. I don't know what is needed in you model without a description or pictures.

a fan is fix on the cooling tower, the air is cool down the water, so i need 2 fluid.

Boris_M December 14, 2009 05:39

Ok, but do you really need the water. Since FloEFD or FloWorks is not capable of calculating phase transition, you won't have water boiling and becoming steam or the other way around. So if the water has a certain temperature but you are not interested in the flow of the water it selfe but the flow of the air and the temperature change in the air you could maybe simulate the surface of the cool water with an approximation of a fixed temperature on the surface of a solid. Or separate the water with a thin solid sheet where you apply a self-defined solid material with super thermal conductivity to realize an ideal contact between water an air.

kacee December 14, 2009 05:46

Quote:

Originally Posted by Boris_M (Post 239913)
Ok, but do you really need the water. Since FloEFD or FloWorks is not capable of calculating phase transition, you won't have water boiling and becoming steam or the other way around. So if the water has a certain temperature but you are not interested in the flow of the water it selfe but the flow of the air and the temperature change in the air you could maybe simulate the surface of the cool water with an approximation of a fixed temperature on the surface of a solid. Or separate the water with a thin solid sheet where you apply a self-defined solid material with super thermal conductivity to realize an ideal contact between water an air.

since my paper title is investigate the temperature drop of the water, i cant ignore the water, and the water not going to change phase, the initial temperature will be apply 60 deg celcius.

Boris_M December 14, 2009 07:04

In this case I would use the thin super thermal conducting solid to separate the water from the air.


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