Model instability With Low SPH Viscosity
Crashphys
Altair Community Member
I have noticed in various simulations that viscosity can cause your simulation to experience a great deal of energy error. For example, in the two simulations I have attached, the only thing I changed with linear and quadratic bulk viscosity from 2.0 and 1.0 to 2e-30 and 1e-30. In the HighVisc solution, I get proper results. For low visc, there is a sharp decline in energy error and the simulation breaks. You can see the sharp decline in energy error immediately after the first cycle. Can anyone explain why this happens and how to counter it?
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