Multy flow and heat transfer

Carlo_P · November 26, 2020, 03:03

Hey,
I have to simulate the different fluids that flow in a pipe.
The problem is that they have also different temperature.

Which solver do you suggest?

theoretically, the interFoam should be the best, but it doesn't take into account the temperature.

What about buoyantSimpleFoam? Can it take in account two different fluids?

Thanks a lot,
carlo

dlahaye · November 26, 2020, 05:08

Possibly rhoSimpleFoam.

See e.g.
rhoSimpleFoam Negative initial temperature T0 error
Why is it difficult to get rhoSimpleFoam solver running correctly ?

geth03 · November 26, 2020, 05:18

it depends on what insight you want to gain from the simulation!
if you want to resolve the interface between the two phases to examine the flow regime than Volume of Fluid is neccessary,
if it doesn't bother you and it is ok that both phases are interpenetrating continua and share the same pressure field you would need to use the Eulerian-Eulerian-Approach which are the multiphase family of solvers
for example reactingMultiphaseEulerFoam, which can handle energy equation as well.

Carlo_P · November 26, 2020, 05:20

Hey dlahaye,
thanks..
For rhoSimpleFoam is only for one single fluid.
I need for two different fluids.
Thanks

dlahaye · November 26, 2020, 05:29

Agreed with geth03.

Pls. elaborate on the fluids you desire to simulate.

Carlo_P · November 27, 2020, 05:08

Quote:

Originally Posted by geth03

it depends on what insight you want to gain from the simulation!
if you want to resolve the interface between the two phases to examine the flow regime than Volume of Fluid is neccessary,
if it doesn't bother you and it is ok that both phases are interpenetrating continua and share the same pressure field you would need to use the Eulerian-Eulerian-Approach which are the multiphase family of solvers
for example reactingMultiphaseEulerFoam, which can handle energy equation as well.

Thanks, yes, I'm not interested in the interface, since one fluid should mix in the other one.

The simulation is quite simple. Two pipes that become one, with a t cross.
The problem is that the two fluids have different temperatures.

dlahaye · November 27, 2020, 06:21

rhoSimpleFoam is for you.

You can run simpleFoam on the incompressible and isothermal case first, then run rhoSimpleFoam with constant density settings to reproduce simpleFoam, then run rhoSimpleFoam with ideal gas thermodynamics to allow density of hot gas to decrease.

Ishan and Maaike are currently doing exactly the same.

We could form a little squad here.

Carlo_P · November 27, 2020, 06:29

The problem is that I have two different fluid.
Two different densities, two different viscosities, and so on.
So I can't use rhoSimpleFoam.

geth03 · November 30, 2020, 03:38

i found the following solver in OF version 7:

Application
twoLiquidMixingFoam

Description
Solver for mixing 2 incompressible fluids.

Turbulence modelling is generic, i.e. laminar, RAS or LES may be selected.

unfortunately, the energy equation is not implemented.
if you have the skills to code it, it should serve your needs.

November 26, 2020, 03:03	Multy flow and heat transfer	#1
Carlo_P Senior Member Carlo_P Join Date: May 2019 Location: Italy Posts: 176 Rep Power: 7	Hey, I have to simulate the different fluids that flow in a pipe. The problem is that they have also different temperature. Which solver do you suggest? theoretically, the interFoam should be the best, but it doesn't take into account the temperature. What about buoyantSimpleFoam? Can it take in account two different fluids? Thanks a lot, carlo

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November 26, 2020, 05:08		#2
dlahaye Senior Member Domenico Lahaye Join Date: Dec 2013 Posts: 722 Blog Entries: 1 Rep Power: 17	Possibly rhoSimpleFoam. See e.g. rhoSimpleFoam Negative initial temperature T0 error Why is it difficult to get rhoSimpleFoam solver running correctly ?

November 26, 2020, 05:18		#3
geth03 Senior Member Join Date: Dec 2019 Location: Cologne, Germany Posts: 355 Rep Power: 8	it depends on what insight you want to gain from the simulation! if you want to resolve the interface between the two phases to examine the flow regime than Volume of Fluid is neccessary, if it doesn't bother you and it is ok that both phases are interpenetrating continua and share the same pressure field you would need to use the Eulerian-Eulerian-Approach which are the multiphase family of solvers for example reactingMultiphaseEulerFoam, which can handle energy equation as well.

November 26, 2020, 05:20		#4
Carlo_P Senior Member Carlo_P Join Date: May 2019 Location: Italy Posts: 176 Rep Power: 7	Hey dlahaye, thanks.. For rhoSimpleFoam is only for one single fluid. I need for two different fluids. Thanks

November 26, 2020, 05:29		#5
dlahaye Senior Member Domenico Lahaye Join Date: Dec 2013 Posts: 722 Blog Entries: 1 Rep Power: 17	Agreed with geth03. Pls. elaborate on the fluids you desire to simulate.

November 27, 2020, 06:21		#7
dlahaye Senior Member Domenico Lahaye Join Date: Dec 2013 Posts: 722 Blog Entries: 1 Rep Power: 17	rhoSimpleFoam is for you. You can run simpleFoam on the incompressible and isothermal case first, then run rhoSimpleFoam with constant density settings to reproduce simpleFoam, then run rhoSimpleFoam with ideal gas thermodynamics to allow density of hot gas to decrease. Ishan and Maaike are currently doing exactly the same. We could form a little squad here.

November 27, 2020, 06:29		#8
Carlo_P Senior Member Carlo_P Join Date: May 2019 Location: Italy Posts: 176 Rep Power: 7	The problem is that I have two different fluid. Two different densities, two different viscosities, and so on. So I can't use rhoSimpleFoam.

November 30, 2020, 03:38		#9
geth03 Senior Member Join Date: Dec 2019 Location: Cologne, Germany Posts: 355 Rep Power: 8	i found the following solver in OF version 7: Application twoLiquidMixingFoam Description Solver for mixing 2 incompressible fluids. Turbulence modelling is generic, i.e. laminar, RAS or LES may be selected. unfortunately, the energy equation is not implemented. if you have the skills to code it, it should serve your needs.