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water sloshing in oscillating tank (problem using udf Define_ZONE_MOTION)

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Old   April 1, 2013, 01:37
Default water sloshing in oscillating tank (problem using udf Define_ZONE_MOTION)
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Sumit Tambe
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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?
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Old   April 2, 2013, 06:49
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Paritosh Vasava
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1. Is there a space in 'DEFINE_ZONE_MOTION(fmotion,omega,axis,origin,veloc ity,time,dtime)' or just a typo?

2. It is possible that 1 sec is too short time to notice sloshing, try bit longer simulation.

Last edited by vasava; April 2, 2013 at 07:20.
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Old   April 2, 2013, 08:00
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Sumit Tambe
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Quote:
Originally Posted by vasava View Post
1. Is there a space in 'DEFINE_ZONE_MOTION(fmotion,omega,axis,origin,veloc ity,time,dtime)' or just a typo?

2. It is possible that 1 sec is too short time to notice sloshing, try bit longer simulation.
Yeah, its a typo.
Time is surely not an issue. Instead of trying with a moving mesh, I varied a body force. Its giving good results even for small simulation time. Just that you wont see the mesh moving. but Its fairly sufficient for the analysis.
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Old   April 2, 2013, 08:18
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Paritosh Vasava
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You said it first! I was just going to suggest that. So is everything fine now?
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Old   April 2, 2013, 10:46
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Sumit Tambe
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Yup!! everything is great!
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Old   November 9, 2013, 10:24
Default sloshing
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Puneet
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Quote:
Originally Posted by Tamsu View Post
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?
sir i m facing same problems...how did u rectify those..plz help me out
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Old   May 16, 2014, 08:42
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Sumit,

Can you please let me know how to go about solving this problem

Thanks,Samwize
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