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-   -   Basic UDF for unsteady mass flow rate (http://www.cfd-online.com/Forums/fluent-udf/70404-basic-udf-unsteady-mass-flow-rate.html)

emmkell November 23, 2009 12:39

Basic UDF for unsteady mass flow rate
 
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;
else
F_PROFILE(f, thread, position) = 0;
}
end_f_loop(f, thread)
}

arashoil November 27, 2011 12:10

udf
 
hi,

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

mohammadamin67 September 9, 2013 04:48

udf
 
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?
thanks.
M.Azizi


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