CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT > Fluent UDF and Scheme Programming

Basic UDF for unsteady mass flow rate

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   November 23, 2009, 11:39
Default Basic UDF for unsteady mass flow rate
New Member
Join Date: Sep 2009
Posts: 17
Blog Entries: 1
Rep Power: 16
emmkell is on a distinguished road
Hi All

Shown below is a UDF that I am using in order to turn on and off mass flow rate (to simulate inhalation). The UDF is interpreted by Ansys Fluent with no problems, but when i run the model, it is activating the flow after 1 second, but it is not switching it back off.

Would anyone have any idea why this is? Any help is greatly appreciated

#include "udf.h"

DEFINE_PROFILE(unsteady_mass_flow_rate, thread, position)

face_t f;
real t = CURRENT_TIME;
begin_f_loop(f, thread)
if (CURRENT_TIME <= 1)
F_PROFILE(f, thread, position) = 0;
else if (1 < t <= 2)
F_PROFILE(f, thread, position) = 0.00003;
F_PROFILE(f, thread, position) = 0;
end_f_loop(f, thread)
emmkell is offline   Reply With Quote

Old   November 27, 2011, 11:10
Default udf
New Member
Join Date: Jun 2011
Posts: 7
Rep Power: 15
arashoil is on a distinguished road

can i modelling asphaltene precipitation that exist in crude oil by uusing ceramic filter monolit by defult formolation in fluent?

i want to modelling separation of asphaltene from crude oil by 19-channel ceramic filter,but i think it is not define in FLUENT that precipitate asphaltene on surface of ceramic channel base on diffrences between pore size.

i must write UDF for this porpuse or not?

most of oil flow must pass through the membrane wall and most of asphaltene must form a gel-layer and precipitation on inner surface od channel.

please help me as soon as possible

thank you so much
arashoil is offline   Reply With Quote

Old   September 9, 2013, 04:48
Default udf
New Member
mohammad azizi
Join Date: Sep 2013
Location: Iran, Tehran, TMU
Posts: 2
Rep Power: 0
mohammadamin67 is on a distinguished road
Hi all
I want to write a udf defining the value of the pressure in a pressure inlet boundary vs to value of mass flow rate passing that bouandary. can anyone help me or write this udf for me?
mohammadamin67 is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
The reporting of mass flow rate summer FLUENT 1 July 12, 2007 09:35
mass flow rate entering and exiting a cell samir bensaid FLUENT 0 July 4, 2007 05:37
User defined function of mass flow rate Eric FLUENT 1 April 22, 2005 18:15
How to define mass flow rate using UDF? SAMUEL FLUENT 3 December 25, 2004 00:36
Mass flow rate Siang FLUENT 1 December 23, 2003 02:47

All times are GMT -4. The time now is 20:29.