[hamed_roozegar]

<H1 style="MARGIN: 12pt 0in 3pt; TEXT-ALIGN: justify">im tring to model a 3d open channel flow. i dont know if i have modeled correctly.

can anyone check this stages? thanks.

fluent 3ddp

file ® read case .

grid ® check.

define ® models ® solver ® ok.

define ® models ® multiphase ® volume of fluid ® open channel flow ® ok ® implicit body force ® ok.

define ® models ® energy ® not selected ® ok.

define ® models ® viscous ® k – epsilon model ® standard ® enhanced wall treatment ® pressure gradient effects ® ok .

define ® materials ® water liquid ® copy ® create.

Define ® phases ® phase 1 ® air, phase 2 ® water liquid ® close.

Define ® operation conditions ® gravity ® y coordinate -9.81 ® specified operation density selected ® ok.

Define ® boundary conditions ® vel in ® velocity inlet ® phase mixture ® set ® velocity specification method ® components ® z velocity 0.25m/s ® specification method ® k and epsilon ® ok.

Define ® boundary conditions ® vel in ® velocity inlet ® phase 2 ® multiphase ® volume fraction 1 ® ok.

Define ® boundary conditions ® pressure outlet ® pressure outlet ® phase mixture ® set ® specification method ® k and epsilon ® ok.

Define ® boundary conditions ® pressure outlet ® pressure outlet ® phase water ® multiphase ® backflow volume fraction 1 ® ok.

Define ® boundary conditions ® pressure up ® pressure outlet ® phase mixture ® set ® specification method ® k and epsilon ® ok. Close.

Solve ® controls ® solutions ® piso algorithm ® pressure body force weighted ® ok.

Adapt ® region ® x between ( -1.5 ,1.5) , y( 0,2) , z ( -6 , 6) , adapt ® yes ® mark ® close.

Solve ® initialize ® initialize ® init ® close.

Solve ® initialize ® patch ® volume fraction ® value 1 ® patch.

Solve ® monitors ® residual ® plot select ® ok.

Solve ® iterate 1000000 ® iterate.

</H1>

[Ralf Schmidt]

Hi!

I don't know about the specific VOF model settings... but the others look good...

except: you have no grid @ scale ....

And I would turn off the standard fluent convergence check in the residuals menu...

Ralf

[zhaopeng]

you can turn on the open channel flow option in boundary condition panel if you use pressure inlet or mass flow inlet in inlet boundary and pressure outlet or outflow in outlet boundary.

[hamed_roozegar]

it does'nt work. the velocities are much more than real.

[zhaopeng]

you can define the velocity magnitude in pressure inlet boundary after turning on open channel flow option.

[hamed_roozegar]

thanks. i did it but it looks that the water is vaporing little by little.
the water goes up . it looks like that the gravity is opposite.

[zhaopeng]

How did you set the outllet boundary?

[hamed_roozegar]

outlet boundary:
multiphase : open channel : free surface level between (0,2).

[mamadnamaie]

hi you should put gravity in z direction not y

[Philipov]

Look the mesh quality and I can not see what is the time step of the calculation. VOF method is used often as an unsteady ....

[gomane8]

Adapt ® region ® x between ( -1.5 ,1.5) , y( 0,2) , z ( -6 , 6) , adapt ® yes ® mark ® close

i think that you have not to mark the region that you have adapt!!! iam not very sur but i hope for those ho read that topic to search and confirme :

[gomane8]

Originally Posted by gomane8

Adapt ® region ® x between ( -1.5 ,1.5) , y( 0,2) , z ( -6 , 6) , adapt ® yes ® mark ® close

i think that you have not to mark the region that you have adapt!!! iam not very sur but i hope for those ho read that topic to search and confirme :

you are wright .....not to adapt !!!! just MARK......iam sorry

[Yapoo]

Originally Posted by hamed_roozegar

<H1 style="MARGIN: 12pt 0in 3pt; TEXT-ALIGN: justify">im tring to model a 3d open channel flow. i dont know if i have modeled correctly.

can anyone check this stages? thanks.

fluent 3ddp

file ® read case .

grid ® check.

define ® models ® solver ® ok.

define ® models ® multiphase ® volume of fluid ® open channel flow ® ok ® implicit body force ® ok.

define ® models ® energy ® not selected ® ok.

define ® models ® viscous ® k – epsilon model ® standard ® enhanced wall treatment ® pressure gradient effects ® ok .

define ® materials ® water liquid ® copy ® create.

Define ® phases ® phase 1 ® air, phase 2 ® water liquid ® close.

Define ® operation conditions ® gravity ® y coordinate -9.81 ® specified operation density selected ® ok.

Define ® boundary conditions ® vel in ® velocity inlet ® phase mixture ® set ® velocity specification method ® components ® z velocity 0.25m/s ® specification method ® k and epsilon ® ok.

Define ® boundary conditions ® vel in ® velocity inlet ® phase 2 ® multiphase ® volume fraction 1 ® ok.

Define ® boundary conditions ® pressure outlet ® pressure outlet ® phase mixture ® set ® specification method ® k and epsilon ® ok.

Define ® boundary conditions ® pressure outlet ® pressure outlet ® phase water ® multiphase ® backflow volume fraction 1 ® ok.

Define ® boundary conditions ® pressure up ® pressure outlet ® phase mixture ® set ® specification method ® k and epsilon ® ok. Close.

Solve ® controls ® solutions ® piso algorithm ® pressure body force weighted ® ok.

Adapt ® region ® x between ( -1.5 ,1.5) , y( 0,2) , z ( -6 , 6) , adapt ® yes ® mark ® close.

Solve ® initialize ® initialize ® init ® close.

Solve ® initialize ® patch ® volume fraction ® value 1 ® patch.

Solve ® monitors ® residual ® plot select ® ok.

Solve ® iterate 1000000 ® iterate.

</H1>

salam aqaie hamed
man rooie ie masaleie moshabehe in masaleie shoma kar mikonam
dar morede taeen sharaiete marzi be moshkel bar khordam mishe komakam konid?

[mkhodier]

Did you guys know the problem, if yes, could u please tell me what was it. Thankls

[flow_CH]

Originally Posted by hamed_roozegar

thanks. i did it but it looks that the water is vaporing little by little.
the water goes up . it looks like that the gravity is opposite.

I have this problem too.
I am using "Open channel flow" option in inlet and outlet boundaries. It is look like water goes up in pressure inlet boundary.
Where is the origin of the free surface and bottom. Is it in bottom of any boundary or origin of coordinates?
help me please.

[mohammad87]

How do we model the two phase (water-gas) ejector with vof in fluent??

I thank for the help..

[mohammad87]

Please explain the mixed model for liquid-gas ejector simulation

[Mohammad80]

Hi.
In the attached picture I did a simulation of a pier into a channel using FLUENT but the drag force I got is negative. I used a pressure inlet and pressure outlet with giving the water and bottom levels by ticking on the open channel choice. Any tips please?