SPH water propagation is late

comp_mech

Hello,
I'm doing some simulations of open channel flow / flooding with DualSPHysics and I have a question regarding SPH simulations.

I've been comparing it on some cases with other FVM-VOF solvers and I've noticed that when a problem is somewhat bigger in size, water propagation in SPH seems to be late behind VOF.

Now, my question is, what could cause such a thing?
Is there a parameter that could regulate how fast the propagation of particles would be (I've been using the default parameters for the dam break with obstacle case) or is the problem in the mere fact that I'm not putting enough particles so the fluid is basically lacking momentum?
Thanks

Alex

The main parameter and the "only" tunning parameter in DualSPHysics is VISCO (generally ALPHA when using artificial viscosity):

1) for dam-breaks and sloshing tanks the value of VISCO should be modified to agree with reference data... since VISCO should vary when changing number of particles (DP)

2) for wave tanks, the value of VISCO=0.01 has shown to provide accurate results.
Reference: Altomare C, Domínguez JM, Crespo AJC, González-Cao J, Suzuki T, Gómez-Gesteira M, Troch P. 2017. Long-crested wave generation and absorption for SPH-based DualSPHysics model. Coastal Engineering, 127: 37-54 doi: 10.1016/j.coastaleng.2017.06.004.

C_Kesanapalli

Can you provide me some reference related to the change in viscosity with respect to particle spacing in sloshing tank?

Because I am trying to simulate a sloshing tank simulation and results show that the peak impact pressure on the tank wall is at different time steps for different particle spacings. (Though peak pressure value is almost same).

Alex

the value will depende on the problem and the number of particles....
so you should try different values 0.01, 0.02, 0.05, 0.1 ...