simulation on cooling tower

kacee · December 2, 2009, 22:45

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

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

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

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

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

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.

December 2, 2009, 22:45	simulation on cooling tower	#1
kacee New Member jasper Join Date: Dec 2009 Posts: 12 Rep Power: 16	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? nrhaha likes this.

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December 4, 2009, 02:48		#2
kacee New Member jasper Join Date: Dec 2009 Posts: 12 Rep Power: 16	can anyone told me tis isint a limitation.

December 12, 2009, 09:20		#5
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 24	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.

December 13, 2009, 13:19		#7
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 24	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.

December 14, 2009, 05:39		#9
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 24	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.

December 14, 2009, 07:04		#11
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 24	In this case I would use the thin super thermal conducting solid to separate the water from the air.