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outlet boundary condition in alpha.water with interFoam for faster performance |
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October 26, 2017, 11:03 |
outlet boundary condition in alpha.water with interFoam for faster performance
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#1 |
New Member
Oliver K
Join Date: May 2017
Posts: 15
Rep Power: 9 |
Hey there,
I got an issue with setting a better outlet boundary condition in an interFoam simulation. The case: I got an reservoir with water at free surface conditions and air (so two phases). I got an outlet/inlet at the bottom of the reservoir from where water could get in and out. The top of the reservoir is with an atmosphere patch where air could get in but no water out. The issue is as followed: I don't get any problems for the case that water is flooding in the reservoir. But the problem is my case where the water is flooding out. When I set (in my opinion) the right boundary conditions the simulation is really slow, like 12 seconds of simulations with 12 hours and 60 cores running. So I want to simplify it and just let water out at the outlet. So i tried just to set the outlet patch in alpha.water to fixedValue with value 1. It's running a lot faster but max (alpha.water) is rising really slowly so the case is running for some hours but after around 70 simulation seconds the time steps decrease massively and stops. my outlet BC are for U: inletOutlet p_rgh: fixedValue alpha.water: works with inletOutlet but is really slow alpha.water: fails after some hours of calculating with fixedValue Does anyone have any experience how to set the boundary condition for my outlet at alpha.water to let just water out or speed my calculation up and not using fixedValue? Cheers, Oli |
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October 27, 2017, 03:54 |
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#2 |
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Pascal Balz
Join Date: Feb 2015
Location: Germany
Posts: 44
Rep Power: 11 |
Hi Oli,
if I got you right you are simulating an open tank with outflow? Try these boundary conditions: outlet Code:
U: inletOutlet p_rgh: fixedValue alpha.water: inletOutlet Code:
U: pressureInletOutletVelocity p_rgh: totalPressure alpha.water: fixedValue
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Regards, Pascal |
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October 27, 2017, 05:02 |
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#3 | ||
New Member
Oliver K
Join Date: May 2017
Posts: 15
Rep Power: 9 |
Quote:
Quote:
Got any other idea how the boundary condition could be set for alpha.water? Thanks a lot in advance Cheers, Oli |
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October 27, 2017, 05:18 |
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#4 | |
Member
Pascal Balz
Join Date: Feb 2015
Location: Germany
Posts: 44
Rep Power: 11 |
Quote:
So are you using the same inlet boundary conditions as I posted? In fact I simulated a similar problem a few weeks ago and my inlet boundary conditions made the solver slow down. In my case these exact BCs worked out to deliver a fast solution without decreasing timesteps. If this doesn't work out I have no other idea what could be the problem...
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Regards, Pascal |
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June 3, 2020, 07:08 |
free surface goes down versus time
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#5 |
Member
le
Join Date: Nov 2009
Location: seoul
Posts: 34
Rep Power: 17 |
Hello Alls,
I use OF1812 and run case from tutorial waveMakerFlap and modify height of wave at inlet from 0.06 to 0.1m Everything goes well but the free surface drop at the outlet. Can you give me some hints ? highly appreciated your comments. |
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May 18, 2022, 23:38 |
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#6 | |
Member
Mahmoud
Join Date: Nov 2020
Location: United Kingdom
Posts: 43
Rep Power: 6 |
Quote:
Have you found the answer to this question? Cheers |
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