Problem faced when running for longer time and using mdbc
I faced a problem when I simulate an experimental flume with a rock structure using DualSPhysics. The flume is about 20m x 1.5m x 1.2 m (length x width x height), and the wave generator is piston which will generate irregular wave with JONSWAP theory. I need to run 1200 seconds (20 minutes) to collect the overtopping data (in XML file) across the crest of the structure. I run in 2D case and dp=0.015 m, with time step = 10s.
Figure below shows that the initial water level in paraview:
Figure below shows the water level after simulation:
The problem is that:
- When I run for mdbc, there is a warning come out, saying that: " There are 1289 of 1289 fixed or moving particles boundary without normal data". But if I run with dbc, there is no warning. I hope I could this problem to reduce the voids between the boundary and particles.
- The structure crest height is 0.39m. And it is 17m away from the piston. When I use the physical experimental data in the report which tells me that water level = 0.318m, wave height=0.1 m can cause overtopping. But in my simulation case, there is no water overtop. So I change the data to new case: (as shown in the picture) water level=0.35m and wave height =0.15m. * and I found that the new case give me the overtopping at first but not long after that I observed the weird scenario that occur in Paraview: the water particles is gradually reduced (but I didn't get any warning after completion of the simulation). I think that is the main problem why I still cannot get the water overtop behind the structure in my first case. Can anyone tell me why?? how to solve the problems??
In regards to the first warning, this means that you have no normal vectors for the boundary particles i.e. mDBC is not being used.
When a particle does not have a normal, it defaults to DBC. Therefore you have been running simulations using DBC in reality.
Thank you for your responds. Yes, I also realised the problem.... but why when I run longer time (for example 1200s), 10% of particles out at the end of the simulation? What should I do?