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MAB January 15, 2009 13:04

when simulating Water Waves in a Wave Tank. I wonder which option is best for front and back boundary. Say you have left boundary as Inlet. Right as outflow. Now front and back can either be WALLS or SYMMETRY boudaries. which one is best for wave's propagation from your experience. Thanks in advance

michael barkhudarov January 16, 2009 01:52

Re: WaveTank
The main difference between a symmetry and a wall boundary is that there is no friction at the symmetry boundary. If you are doing a 2D simulation, then you should use symmetry on the front and back. You would use the wall-type BC if that wall represented the actual wall of the tank.


MAB January 16, 2009 06:33

Re: WaveTank
Thanks Michael. In couple of cases( not all) I noticed that water level rises after 10 or 12 seconds even with Outflow BC implemented on the downstream end ( with Allowing fluid to enter from outflow). Could you suggest any remedy for this. Thanks again.

michael barkhudarov January 21, 2009 10:22

Re: WaveTank
How much does the level rise? There were some improvements in the latest release, 9.3, for volume conservation in such cases - what version are you using?

MAB January 21, 2009 11:03

Re: WaveTank
I am using v 9.3.1 ( the latest version). I think it rises gradually up to 5mm(or more) in a case of 30s .

michael barkhudarov January 27, 2009 10:12

Re: WaveTank
There is generally no guarantee that the amount of fluid entering at a wave boundary is exactly the same as that leaving at the outflow boundary. The mismatch maybe worse for shorter and higher waves. How many wave periods are in 30 seconds in your case?


michael barkhudarov February 3, 2009 01:26

Re: WaveTank
Over how many wave periods?

MAB February 3, 2009 07:07

Re: WaveTank
Thanks...I am currently using a wave of period 1s.

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