Water heat exchange with heRhoThermo?

BenFranklinIII · July 23, 2015, 17:26

Hallo,

im using OpenFoam on this site. Simscale.com

So far so good, but when I calculate heat transfere I can only choose the following model.

Thermo Type: herhothermo
pure mixture
transport const
thermo model: hconst
perfectgas
species model specie:

My question is. Can this model be used to simulate water if all the substance constants are changed to the values of water or does a different thermo type has to be used?

Tanks a lot.

Best regards.

Benjamin

jprobst · July 24, 2015, 10:35

Hi Benjamin,

you can use the buoyant solver family for this kind of problems. SimScale offers buoyantSimpleFoam and buoyantPimpleFoam under the category "Natural convective heat transfer".
You can optionally choose a turbulence model and select transient (buoyantPimpleFoam) or steady-state (buoyantSimpleFoam) behaviour.
These solvers are well-suited for heat transfer and convection problems with buoyancy.

Best regards
Johannes

BenFranklinIII · July 27, 2015, 04:20

Hallo,

thank you for your answer.

I usedbuoyantSimpleFoam and KOmega-SST as a turbulence model. The whole thin in stationäre form.

In the Model section i hve to choose perfectGas Every other value is the value of water at 315K.

What I model is the follwowing.
In a pipe fo 13mm diameter I place a rod with 7mm diamtere coaxially. In the ring cavity between the two water is used as a cooling fluid. The volume flow is 11L/min.
The power produced by the rod is 1200W.

I expected something by analytical calculations a litle lower than 373K. Instead i get something arround 1250K. That is absalutely impossible.

I think it has something to do with te ideal gas thing.

Can you point me into the right direction.

Thank you very much.

Best regards.

Benjamin

July 23, 2015, 17:26	Water heat exchange with heRhoThermo?	#1
BenFranklinIII New Member Benjamin Bergmann Join Date: Jul 2015 Posts: 4 Rep Power: 10	Hallo, im using OpenFoam on this site. Simscale.com So far so good, but when I calculate heat transfere I can only choose the following model. Thermo Type: herhothermo pure mixture transport const thermo model: hconst perfectgas species model specie: My question is. Can this model be used to simulate water if all the substance constants are changed to the values of water or does a different thermo type has to be used? Tanks a lot. Best regards. Benjamin

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July 24, 2015, 10:35		#2
jprobst New Member Johannes Probst Join Date: Aug 2013 Posts: 8 Rep Power: 12	Hi Benjamin, you can use the buoyant solver family for this kind of problems. SimScale offers buoyantSimpleFoam and buoyantPimpleFoam under the category "Natural convective heat transfer". You can optionally choose a turbulence model and select transient (buoyantPimpleFoam) or steady-state (buoyantSimpleFoam) behaviour. These solvers are well-suited for heat transfer and convection problems with buoyancy. Best regards Johannes

July 27, 2015, 04:20		#3
BenFranklinIII New Member Benjamin Bergmann Join Date: Jul 2015 Posts: 4 Rep Power: 10	Hallo, thank you for your answer. I usedbuoyantSimpleFoam and KOmega-SST as a turbulence model. The whole thin in stationäre form. In the Model section i hve to choose perfectGas Every other value is the value of water at 315K. What I model is the follwowing. In a pipe fo 13mm diameter I place a rod with 7mm diamtere coaxially. In the ring cavity between the two water is used as a cooling fluid. The volume flow is 11L/min. The power produced by the rod is 1200W. I expected something by analytical calculations a litle lower than 373K. Instead i get something arround 1250K. That is absalutely impossible. I think it has something to do with te ideal gas thing. Can you point me into the right direction. Thank you very much. Best regards. Benjamin