Refinement for VOF wave

arun7328 · October 22, 2013, 09:59

Please can anyone help me with refinement for generating your wave. I am trying to simulate a first order wave with amplitude of 0.1m and length 5 mt. The total domain is 75X10X1. y axis forms the direction of amplitude. I have used a block of height 0.3 mts to refine the free surface. The mesh sizes in x and z direction is 0.0625(5/80) and y axis is 0.01 (0.2/20). I am getting a good comparison of pressure and velocity. My concern is the total cell count is very high. I am a wary because of this. When I will be working with ship wave interactions the total mesh can be too high, increasing the time. Also if the wave is so sensitive to mesh size, even for a small of amplitude or wavelength would require remeshing.
Could you please share your knowledge on wave simulation please?

Thanks
Regards
Arun
PhD student
Southampton University

dai549592484 · October 25, 2013, 06:54

Hi, I would recommand you to use symmetry plane and simulate only half ship if it is axis symmetry.

BTW, have you ever monitor the wave elevation time history at some certain place in the wave field? I got a result which is far from satisfied. Looking forward your answer...

Best Regards
David

arun7328 · October 25, 2013, 07:00

Quote:

Originally Posted by dai549592484

Hi, I would recommand you to use symmetry plane and simulate only half ship if it is axis symmetry.

BTW, have you ever monitor the wave elevation time history at some certain place in the wave field? I got a result which is far from satisfied. Looking forward your answer...

Best Regards
David

Dear David,
Think it is a coincidence. I am trying to think of how to plot the wave elevation. Could you please share your thought? When I compare the pressures and velocities at different points in X axis(propagation direction), it seems to be not very bad. I tried to check the wave elevation by placing probes very close to the amplitude(above and below) and get VOF heavy fluid. Even that seems to come out pretty good. Just got the results today. If you know how to plot to elevation directly can you please advice?

dai549592484 · October 25, 2013, 07:17

Dear Arun

May I have a look at your wave elevation history? There's no direct way to get the wave elevation. I am using a slightly different method from you, created a line probe by intersceting two plane section and integral the VOF (water) along the line, this is the way Fluent used. I have no idea how to upload picture, I will leave my email address to you.

ksss · January 21, 2019, 09:57

In my case in STAR CCM wave elevation history over time is not constant. the initial wave height gets damped when reaching the vessel or reaching half domain if vessel is not considered.

October 22, 2013, 09:59	Refinement for VOF wave	#1
arun7328 Member Arun Krishnan.L.H Join Date: Jan 2013 Posts: 75 Rep Power: 13	Please can anyone help me with refinement for generating your wave. I am trying to simulate a first order wave with amplitude of 0.1m and length 5 mt. The total domain is 75X10X1. y axis forms the direction of amplitude. I have used a block of height 0.3 mts to refine the free surface. The mesh sizes in x and z direction is 0.0625(5/80) and y axis is 0.01 (0.2/20). I am getting a good comparison of pressure and velocity. My concern is the total cell count is very high. I am a wary because of this. When I will be working with ship wave interactions the total mesh can be too high, increasing the time. Also if the wave is so sensitive to mesh size, even for a small of amplitude or wavelength would require remeshing. Could you please share your knowledge on wave simulation please? Thanks Regards Arun PhD student Southampton University

January 21, 2019, 09:57	Wave elevation	#5
ksss New Member sri Join Date: Jan 2019 Posts: 2 Rep Power: 0	In my case in STAR CCM wave elevation history over time is not constant. the initial wave height gets damped when reaching the vessel or reaching half domain if vessel is not considered.

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October 25, 2013, 06:54		#2
dai549592484 Member David Join Date: Nov 2011 Posts: 39 Rep Power: 15	Hi, I would recommand you to use symmetry plane and simulate only half ship if it is axis symmetry. BTW, have you ever monitor the wave elevation time history at some certain place in the wave field? I got a result which is far from satisfied. Looking forward your answer... Best Regards David

October 25, 2013, 07:17		#4
dai549592484 Member David Join Date: Nov 2011 Posts: 39 Rep Power: 15	Dear Arun May I have a look at your wave elevation history? There's no direct way to get the wave elevation. I am using a slightly different method from you, created a line probe by intersceting two plane section and integral the VOF (water) along the line, this is the way Fluent used. I have no idea how to upload picture, I will leave my email address to you.