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-   -   Using DEFINE_ZONE_MOTION udf to study sloshing in lateral excitations (http://www.cfd-online.com/Forums/fluent-udf/115445-using-define_zone_motion-udf-study-sloshing-lateral-excitations.html)

Tamsu March 31, 2013 07:50

Using DEFINE_ZONE_MOTION udf to study sloshing in lateral excitations
 
hello everyone,
I am simulating 2D sloshing of water due to oscillatory motion of a square tank. Here is a small description:
model=VOF: Implict, with zonal discretization.
gravity in 'y' dirctn.
Tank: 0.2m x 0.2m sqaure tank, closed walls.
Mesh: structured, finer at the water-air interface.
filled depth: 0.04m
UDF:
#include <udf.h>
DEFINE_ZONE_MOTION(fmotion,omega,axis,origin,veloc ity,time,dtime)
{
real velocity={0.6282*sin(62.82*time),0.0,0.0};
return;
}

UDF is hooked up with both of the cell zones.
Walls: moving walls, with relative velocity(adjacent to cell zone) =0 m/s
time-step size=0.0001 s
during calculation x and y velocity residuals are remaining almost constant until I reduce momentum URF to 0.001, then after the solution rapidly converges.
But water remains stationary as before. The free surface orientation does not change with time. even after 1 second of flow time.
Can anybody help me out?

iwan September 20, 2013 15:52

Quote:

Originally Posted by Tamsu (Post 417412)
hello everyone,
I am simulating 2D sloshing of water due to oscillatory motion of a square tank. Here is a small description:
model=VOF: Implict, with zonal discretization.
gravity in 'y' dirctn.
Tank: 0.2m x 0.2m sqaure tank, closed walls.
Mesh: structured, finer at the water-air interface.
filled depth: 0.04m
UDF:
#include <udf.h>
DEFINE_ZONE_MOTION(fmotion,omega,axis,origin,veloc ity,time,dtime)
{
real velocity={0.6282*sin(62.82*time),0.0,0.0};
return;
}

UDF is hooked up with both of the cell zones.
Walls: moving walls, with relative velocity(adjacent to cell zone) =0 m/s
time-step size=0.0001 s
during calculation x and y velocity residuals are remaining almost constant until I reduce momentum URF to 0.001, then after the solution rapidly converges.
But water remains stationary as before. The free surface orientation does not change with time. even after 1 second of flow time.
Can anybody help me out?

Hi Tamsu,
Have you done your 2D sloshing project?I hope you make it easy
i'amIwan, I'm from Indonesia.I have same project for my thesis.I want to simulate water sloshing in enclosed rectangular tank. But i have problem, i don't have detail references or tutorial how to simulate sloshing. Could you please help me step by step how to simulate water sloshing using fluent?
Many thanks Tamsu...

iwan_bimaness@yahoo.com

Tamsu September 21, 2013 01:08

Quote:

Originally Posted by iwan (Post 452812)
Hi Tamsu,
Have you done your 2D sloshing project?I hope you make it easy
i'amIwan, I'm from Indonesia.I have same project for my thesis.I want to simulate water sloshing in enclosed rectangular tank. But i have problem, i don't have detail references or tutorial how to simulate sloshing. Could you please help me step by step how to simulate water sloshing using fluent?
Many thanks Tamsu...

iwan_bimaness@yahoo.com

hello iwan,
Yeah it is easy once you know the procedure. will communicate through email.

Mohammad80 October 20, 2013 17:14

ANSYS animation help
 
Hello Tamsu

Could you please help me?
I have a problem writing a UDF to produce motion for a blade.
I hope you can contact me at my email:

mas20001920@yahoo.com

Regards.


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