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Old   May 23, 2011, 13:40
Default gravity current modelling
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N. Aslican YILMAZ
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Hi!
I'm trying to model a simple gravity current flow Using FLUENT 12.0. It's a very simple one because I'll verify the model results by comparing them with experimental ones. Experimental flume is 4.25 m in length and 0.5 m in depth. first 0.25x0.25 is initially filled with water and at t=0 the lock is opened and gravity flow is recorded. To model this problem I've used. VOF implicit with enabled open channel flow and implicit body force options. For viscous model I've used k-epsilon Realizable with enhanced wall treatment (pressure gradient effects enabled).
The problem with the model is water propagates too slow. Could you let me a hand? Do you have an idea what i have done wrong?

Thank you so much for your time!
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Old   September 17, 2011, 21:30
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somayyeh m
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Quote:
Originally Posted by asistas View Post
Hi!
I'm trying to model a simple gravity current flow Using FLUENT 12.0. It's a very simple one because I'll verify the model results by comparing them with experimental ones. Experimental flume is 4.25 m in length and 0.5 m in depth. first 0.25x0.25 is initially filled with water and at t=0 the lock is opened and gravity flow is recorded. To model this problem I've used. VOF implicit with enabled open channel flow and implicit body force options. For viscous model I've used k-epsilon Realizable with enhanced wall treatment (pressure gradient effects enabled).
The problem with the model is water propagates too slow. Could you let me a hand? Do you have an idea what i have done wrong?

Thank you so much for your time!
------------------------------------------------------------
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Old   September 17, 2011, 21:35
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Old   September 18, 2011, 11:50
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Hesham Ezz
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Quote:
Originally Posted by asistas View Post
Hi!
I'm trying to model a simple gravity current flow Using FLUENT 12.0. It's a very simple one because I'll verify the model results by comparing them with experimental ones. Experimental flume is 4.25 m in length and 0.5 m in depth. first 0.25x0.25 is initially filled with water and at t=0 the lock is opened and gravity flow is recorded. To model this problem I've used. VOF implicit with enabled open channel flow and implicit body force options. For viscous model I've used k-epsilon Realizable with enhanced wall treatment (pressure gradient effects enabled).
The problem with the model is water propagates too slow. Could you let me a hand? Do you have an idea what i have done wrong?

Thank you so much for your time!
I want to model the same problem but in a sinuous channel. Actually I failed and I need any help. My problem is I found that the whole domain is filled with the denser fluid and no existence of the water (lighter fluid).
Please I need help in that.
Also, I'm searching for any open channel tutorial
if anybody knows please send me "ezz.hisham@gmail.com"
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Old   September 23, 2011, 21:02
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N. Aslican YILMAZ
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Originally Posted by somy1 View Post
Hi Somy,

Thank you so much for your reply. I see that you've suggested me to give 0 to turbulent viscosity. I'm working with a domain filled with water and mud will have the gravity current in this domain. I still have a very slow propagation. Do you think setting 0 to turbulent viscosity will help?
(by the way i'm sorry for late reply)
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Old   September 24, 2011, 03:01
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Originally Posted by asistas View Post
Hi Somy,

Thank you so much for your reply. I see that you've suggested me to give 0 to turbulent viscosity. I'm working with a domain filled with water and mud will have the gravity current in this domain. I still have a very slow propagation. Do you think setting 0 to turbulent viscosity will help?
(by the way i'm sorry for late reply)
hi
yea
it will help u. but isnot correct way.i read atticles that simulated this current whit k-epsilon model then turbulent viscosity con't be 0.
your current will propagate faster but i don't know velocity, pressure and etc profiles will be corret or no.
beacouse of this i earsed my pervious answer.
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Old   September 24, 2011, 03:07
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somayyeh m
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Quote:
Originally Posted by ezzhisham View Post
I want to model the same problem but in a sinuous channel. Actually I failed and I need any help. My problem is I found that the whole domain is filled with the denser fluid and no existence of the water (lighter fluid).
Please I need help in that.
Also, I'm searching for any open channel tutorial
if anybody knows please send me "ezz.hisham@gmail.com"
hi
Fluent's open chanel tutorial?
where are u comfrom?
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Old   September 24, 2011, 09:17
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Hesham Ezz
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Originally Posted by somy1 View Post
hi
Fluent's open chanel tutorial?
where are u comfrom?
I'm a new fluent user. if you have something to help say it, if not please don't give comments
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Old   September 24, 2011, 09:38
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Originally Posted by ezzhisham View Post
I'm a new fluent user. if you have something to help say it, if not please don't give comments
any new fluent user knows that there is not any help for open chanel simulation in fluent. u must read helps about vof and turbolance.
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Old   September 24, 2011, 16:20
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Pooya
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Quote:
Originally Posted by somy1 View Post
any new fluent user knows that there is not any help for open chanel simulation in fluent. u must read helps about vof and turbolance.
Ansys fluent 12.0 tutorial has a example for open channel simulation with VOF method.
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Old   September 24, 2011, 22:43
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Originally Posted by Yapoo View Post
Ansys fluent 12.0 tutorial has a example for open channel simulation with VOF method.
please I need it
my email is ezz.hisham@gmail.com
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