have a problem in modeling the freesurfaces?

seyedashraf · August 12, 2010, 09:57

im trying to model a spillway
have already designed the gambit file
but have a problem in fluent

seems the water and air are not separated
here is a screenshot

any ideas?

seyedashraf · August 12, 2010, 10:25

by the way
in the boundry conditions screen
the velocity inlet that _is for Water flow rate_ the phase is mixture and i dont know how to change it

maybe its the reason !

johnp · August 12, 2010, 16:08

Hi,

can you clarify what the image represents. i usually view the free surface with a contour plot of volume fraction.

seyedashraf · August 13, 2010, 04:10

Thanks for your Reply in here

the first screenshot was Velocity Vectors'

now this one :
display>contours > contours of phases > water

like i mentioned before
the problem is , i cannot define water and air
however in Gambit , i have created two different velocity inlets for air and water
but in fluent ....!??

johnp · August 13, 2010, 10:30

Try this:

1. create a region (possibly more than one) for the air (Adapt -> Region)
2. initialize your solution
3. Patch the volume fraction for air into the region you created, i.e. set the volume fraction of water to zero (or VF of air to 1.0)
4. run simulation

This assumes you've set everything else up correctly (e.g. included gravity, etc.). Fluent has a VOF tutorial modeling a dambreak that may help get you started. Good luck!

seyedashraf · August 14, 2010, 15:58

I Appreciate your kind help

that DamBreak tutorial was really useful

August 12, 2010, 09:57	have a problem in modeling the freesurfaces?	#1
seyedashraf Member Omid Seyedashraf Join Date: May 2010 Posts: 49 Rep Power: 15	im trying to model a spillway have already designed the gambit file but have a problem in fluent seems the water and air are not separated here is a screenshot any ideas?

August 14, 2010, 15:58		#6
seyedashraf Member Omid Seyedashraf Join Date: May 2010 Posts: 49 Rep Power: 15	I Appreciate your kind help that DamBreak tutorial was really useful Last edited by seyedashraf; August 15, 2010 at 05:57.

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August 12, 2010, 10:25		#2
seyedashraf Member Omid Seyedashraf Join Date: May 2010 Posts: 49 Rep Power: 15	by the way in the boundry conditions screen the velocity inlet that _is for Water flow rate_ the phase is mixture and i dont know how to change it maybe its the reason !

August 12, 2010, 16:08		#3
johnp Member john Join Date: Aug 2010 Location: pasadena, va, usa Posts: 36 Rep Power: 15	Hi, can you clarify what the image represents. i usually view the free surface with a contour plot of volume fraction.

August 13, 2010, 04:10		#4
seyedashraf Member Omid Seyedashraf Join Date: May 2010 Posts: 49 Rep Power: 15	Thanks for your Reply in here the first screenshot was Velocity Vectors' now this one : display>contours > contours of phases > water like i mentioned before the problem is , i cannot define water and air however in Gambit , i have created two different velocity inlets for air and water but in fluent ....!??

August 13, 2010, 10:30		#5
johnp Member john Join Date: Aug 2010 Location: pasadena, va, usa Posts: 36 Rep Power: 15	Try this: 1. create a region (possibly more than one) for the air (Adapt -> Region) 2. initialize your solution 3. Patch the volume fraction for air into the region you created, i.e. set the volume fraction of water to zero (or VF of air to 1.0) 4. run simulation This assumes you've set everything else up correctly (e.g. included gravity, etc.). Fluent has a VOF tutorial modeling a dambreak that may help get you started. Good luck!