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musahossein July 30, 2013 22:55

Wallpressure output from sloshingtank2D raises questions
 
Dear all:

I am modeling a tank 1mX1mX0.1m. Mesh size is 100 Horizontal X 600 Vertical. Water height is 0.4m. The wall pressure is calculated during the interDymFoam run and gives the following output (I am providing a sample here):

# p POINT_DATA 1202
# x y z p
0.05 -0.500525 0 100004
-0.05 -0.500525 0 100004
0.05 -0.500525 -0.00166667 100014
-0.05 -0.500525 -0.00166667 100014
0.05 -0.500525 0.00166667 100002
-0.05 -0.500525 0.00166667 100002
0.05 -0.500525 -0.00333333 100032
-0.05 -0.500525 -0.00333333 100032
0.05 -0.500525 0.00333333 100002
-0.05 -0.500525 0.00333333 100002
0.05 -0.500525 -0.005 100050
-0.05 -0.500525 -0.005 100050
0.05 -0.500525 0.005 100002
-0.05 -0.500525 0.005 100002
0.05 -0.500525 -0.00666667 100068
-0.05 -0.500525 -0.00666667 100068
0.05 -0.500525 0.00666667 100002
-0.05 -0.500525 0.00666667 100002
0.05 -0.500525 -0.00833333 100086
-0.05 -0.500525 -0.00833333 100086
0.05 -0.500525 0.00833333 100002
-0.05 -0.500525 0.00833333 100002
0.05 -0.500525 -0.01 100104
-0.05 -0.500525 -0.01 100104
0.05 -0.500525 0.01 100002
-0.05 -0.500525 0.01 100002
0.05 -0.500525 -0.0116667 100122
-0.05 -0.500525 -0.0116667 100122
0.05 -0.500525 0.0116667 100002
-0.05 -0.500525 0.0116667 100002
0.05 -0.500525 -0.0133333 100140
-0.05 -0.500525 -0.0133333 100140
0.05 -0.500525 0.0133333 100002

Question is:
Are these realistic pressures? and are they in Pascals?
The tank is being laterally displaced with Asin(t/T) where A=0.0145 and T=1.2. So the displacements are very small. So why are the pressures so high? I hope I am missing something here and some one will be kind enough to point out the error to me. Thanks!

musahossein August 2, 2013 16:39

Wallpressure computation in sampleDict
 
Dear all:

I am modeling a tank LXHXb = 1mX1mX0.1m. My z=0 is at the fluid surface. I am running interdymfoam, sloshingtank2D.

Here is a sample output from the wall pressure:
X Y Z P
0.05 -0.4916 0 100096
-0.05 -0.4916 0 100096
0.05 -0.4916 -0.00166667 100106
-0.05 -0.4916 -0.00166667 100106
0.05 -0.4916 0.00166667 100086

Lets look at the last pressure value: P=100086. My pRefvalue=1e5. My static pressure is: 998.2*9.81*0.4=3916 kg/m^2

So my dynamic pressure=100086-100000-3916=-3830 ( a negative value!). What am I doing wrong here?


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