noise in U at the free surface in InterFoam

Jung hoo · October 15, 2016, 22:29

Hello foamers, I set a simple water tank with InterFoam.

First, I didn't generate any flow to evaluate stability.

The upper boundary is set as atmosphere.

Obviously, It seems that there should not be flow rate, but there is some flow rate consistently at the free surface(about 0 ~ 0.3 of magnitude).

I'm planning to set the temperature over the air and water later.

I think that the noise at the free surface in U will affect the distribution of temperature because the convection term includes the flux(phi).

How can I remove the noise?

Any comments will be very helpful.

Thanks!

Phicau · October 16, 2016, 21:27

Hi Jung Hoo,

unfortunately this is a well known issue with no solution yet.

There are extensive discussions here in the forum on how to make it milder. You should look for threads talking about spurious velocities or spurious currents.

Best,

Pablo

Jung hoo · October 17, 2016, 01:54

Thank you for your kind reply. I'll check them!

October 15, 2016, 22:29	noise in U at the free surface in InterFoam	#1
Jung hoo Member Lee Jung Hoo Join Date: Dec 2015 Posts: 37 Rep Power: 10	Hello foamers, I set a simple water tank with InterFoam. First, I didn't generate any flow to evaluate stability. The upper boundary is set as atmosphere. Obviously, It seems that there should not be flow rate, but there is some flow rate consistently at the free surface(about 0 ~ 0.3 of magnitude). I'm planning to set the temperature over the air and water later. I think that the noise at the free surface in U will affect the distribution of temperature because the convection term includes the flux(phi). How can I remove the noise? Any comments will be very helpful. Thanks!

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Thermocapillary free surface flow	zakifoam	OpenFOAM Running, Solving & CFD	10	December 12, 2016 11:44
interFoam stability issue, free surface ship hull	jojosaxo	OpenFOAM Running, Solving & CFD	5	July 7, 2016 17:29
ras interFoam for free surface modeling	ms.mahsa	OpenFOAM Pre-Processing	0	April 18, 2016 12:11
free surface modelling using VOF	sci	Main CFD Forum	10	August 29, 2012 07:43
Multiphase flow. Dispersed and free surface model	Luis	CFX	8	May 29, 2007 18:13

October 16, 2016, 21:27		#2
Phicau Senior Member Pablo Higuera Join Date: Jan 2011 Location: Auckland Posts: 627 Rep Power: 19	Hi Jung Hoo, unfortunately this is a well known issue with no solution yet. There are extensive discussions here in the forum on how to make it milder. You should look for threads talking about spurious velocities or spurious currents. Best, Pablo

October 17, 2016, 01:54		#3
Jung hoo Member Lee Jung Hoo Join Date: Dec 2015 Posts: 37 Rep Power: 10	Thank you for your kind reply. I'll check them!