CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   ANSYS (http://www.cfd-online.com/Forums/ansys/)
-   -   [POLYFLOW] How to define VOF initial fluid fraction? (http://www.cfd-online.com/Forums/ansys/89467-polyflow-how-define-vof-initial-fluid-fraction.html)

cutejerk June 13, 2011 18:57

[POLYFLOW] How to define VOF initial fluid fraction?
 
I want to test a simple 2D VOF model in POLYFLOW. The gravity-driven fluid flow starts from a certain initial shape (e.g. a cap) in a 2D cavity. The only options to define this intial condition in POLYFLOW are under 'initial fluid fraction':
1. map from CSV (Excel) file
2. user defined function

I don't know why 'user defined function' is not available (grey). Anybody here has tried the CSV file for these kind of problems?

I think POLYFLOW's VOF model is not well developed. Because there is no VOF setting for each subdomain. VOF is just simply coupled with the whole domain.

brucecumt December 25, 2012 05:50

Hi cutejerk,

I met the same problem as yours. I tried to use ANSYSPPOLYFLOW 14.0 to do some simulations with VOF model, but I donot know how to patch a initial fluid as a cylinder shape.
have you resolved your problem? Thank you in advance.

Yanlong Li January 2, 2013 06:10

Quote:

Originally Posted by brucecumt (Post 398963)
Hi cutejerk,

I met the same problem as yours. I tried to use ANSYSPPOLYFLOW 14.0 to do some simulations with VOF model, but I donot know how to patch a initial fluid as a cylinder shape.
have you resolved your problem? Thank you in advance.

Hi,

I am learning UDF (user define funciton), I just saw an UDF was set for your situlation as well as its exmple. I forgot it, It's about DEFINE_INITILE or DEFINE_INTE, some thing like that.

OR, if your shape is just a cylinder, you can just use " Adapt->Region" to define a register of cylinder, then patch the initial value in this register.

hope it can help you.

Long

brucecumt January 2, 2013 09:19

Quote:

Originally Posted by Yanlong Li (Post 399711)
Hi,

I am learning UDF (user define funciton), I just saw an UDF was set for your situlation as well as its exmple. I forgot it, It's about DEFINE_INITILE or DEFINE_INTE, some thing like that.

OR, if your shape is just a cylinder, you can just use " Adapt->Region" to define a register of cylinder, then patch the initial value in this register.

hope it can help you.

Long

Hi mate,
I think "adapt"thing you said is about ANSYSFLUENT not POLYFLOW. As I can't find the "adapt"tab in polyflow but Fluent. I guess you are learing UDF of Fluent. Right?
Thank you all the same.

Yanlong Li January 2, 2013 10:32

Quote:

Originally Posted by brucecumt (Post 399738)
Hi mate,
I think "adapt"thing you said is about ANSYSFLUENT not POLYFLOW. As I can't find the "adapt"tab in polyflow but Fluent. I guess you are learing UDF of Fluent. Right?
Thank you all the same.

Yeap, I am learnning Fluent, hehe...:D

Near February 22, 2013 03:58

DEAR, You are right, VOF in polyflow is not so good now, and the initial function in not so powerfull as that in Fluent.
Not the same with you,there five ways to initial under "Initial Fluid Fraction" in my project, namely Constant, Linear function, Multi-ramp, CSV and UDF. In my project , Multi-ramp is OK. I know nothing about CSV. My UDF option is also grey, I think the reason is there are no UDF in your Polyflow. Think about the usage of UDF in Fluent...

wzy_me@163.com, just e-mail me

brucecumt June 6, 2013 03:42

Quote:

Originally Posted by Near (Post 409447)
DEAR, You are right, VOF in polyflow is not so good now, and the initial function in not so powerfull as that in Fluent.
Not the same with you,there five ways to initial under "Initial Fluid Fraction" in my project, namely Constant, Linear function, Multi-ramp, CSV and UDF. In my project , Multi-ramp is OK. I know nothing about CSV. My UDF option is also grey, I think the reason is there are no UDF in your Polyflow. Think about the usage of UDF in Fluent...

wzy_me@163.com, just e-mail me

Hi dude, I have confirmed with technician in ANSYS company that the UDF in POLYFLOW for "Initial Fluid Fraction" is not added in this software and he said it will be added in the subsequent version.

Near June 6, 2013 08:47

Thx,a lot. This question bother me a lot ~.
Quote:

Originally Posted by brucecumt (Post 432362)
Hi dude, I have confirmed with technician in ANSYS company that the UDF in POLYFLOW for "Initial Fluid Fraction" is not added in this software and he said it will be added in the subsequent version.



All times are GMT -4. The time now is 03:14.