VOF Wave propagation

eliphil · October 18, 2017, 04:47

Hey,
I just started using STARCCM+, so do not expect to much knowledge !

I am currently trying to model VOF-Stokes-5th order waves in a simple cuboid with eulerian multiphase. I set up all bc's as stated in the DFBI Head on waves tutorial and as well as stated in the VOF Waves best practices. Same goes for Initial conditions.

The problem i encounter know is, that once i start the simulation, there's only one peak of the wave crest and it's not even propagating along the given direction. It's just stagnating where it is until out of no where everything explodes.
Do I miss something in the definition of the waves or in the BC's / IC??

Hope the description of the problem was specific enough!

ping · October 28, 2017, 01:55

5th order waves have quite differnet settings to 1st order so read about these

blowing up is normally caused by poor dfbi body settings so run with the body locked and ensure that waves work well

or can be poor boundary conditions eg not having vof inlets on all side of the domain other that the outlet

eliphil · November 3, 2017, 08:55

The Blowing up was caused due to reflection on the outlet boundary. Damping fixed this.

Problem I still encounter is, the wave which is propagating just fine wouldnt break. I tried varying the water depth with wall boundaries but that does not seem to take influence of the waves behavior. I took Wall boundaries in the same physics continuum and region as the wave is in.
How can I make the wave understand that the waterdepth is changing??

ping · November 4, 2017, 22:13

you just need a wall boundary where the seabed is and ramp it up to make the water depth smaller

eliphil · November 6, 2017, 03:22

Cheers for the quick answer!
That's what Ive been doing so far. Somehow it still seems like its not effecting the waves behaviour.
But that might be because of poor wave creation. Anyways. I do know now that the wall boundary is not the problem in my simulation! Cheers for that!!!!!

October 18, 2017, 04:47	VOF Wave propagation	#1
eliphil New Member Join Date: Oct 2017 Posts: 4 Rep Power: 8	Hey, I just started using STARCCM+, so do not expect to much knowledge ! I am currently trying to model VOF-Stokes-5th order waves in a simple cuboid with eulerian multiphase. I set up all bc's as stated in the DFBI Head on waves tutorial and as well as stated in the VOF Waves best practices. Same goes for Initial conditions. The problem i encounter know is, that once i start the simulation, there's only one peak of the wave crest and it's not even propagating along the given direction. It's just stagnating where it is until out of no where everything explodes. Do I miss something in the definition of the waves or in the BC's / IC?? Hope the description of the problem was specific enough!

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October 28, 2017, 01:55		#2
ping Senior Member Ping Join Date: Mar 2009 Posts: 556 Rep Power: 20	5th order waves have quite differnet settings to 1st order so read about these blowing up is normally caused by poor dfbi body settings so run with the body locked and ensure that waves work well or can be poor boundary conditions eg not having vof inlets on all side of the domain other that the outlet

November 3, 2017, 08:55		#3
eliphil New Member Join Date: Oct 2017 Posts: 4 Rep Power: 8	The Blowing up was caused due to reflection on the outlet boundary. Damping fixed this. Problem I still encounter is, the wave which is propagating just fine wouldnt break. I tried varying the water depth with wall boundaries but that does not seem to take influence of the waves behavior. I took Wall boundaries in the same physics continuum and region as the wave is in. How can I make the wave understand that the waterdepth is changing??

November 4, 2017, 22:13		#4
ping Senior Member Ping Join Date: Mar 2009 Posts: 556 Rep Power: 20	you just need a wall boundary where the seabed is and ramp it up to make the water depth smaller

November 6, 2017, 03:22		#5
eliphil New Member Join Date: Oct 2017 Posts: 4 Rep Power: 8	Cheers for the quick answer! That's what Ive been doing so far. Somehow it still seems like its not effecting the waves behaviour. But that might be because of poor wave creation. Anyways. I do know now that the wall boundary is not the problem in my simulation! Cheers for that!!!!!