I have a problem with the 3D calculation of SPHysics.

I modeled my problem in 2D (SPHYSICS_2D_v2.2.001) and it worked very well. I get a plausible pressure distribution and path of motions of the particles. Afterwards I generated an 3D geometry and tried SPHysics 3D (SPHYSICS_3D_2.2.001).

In this setup all particles had the pressure value zero. The particles move only with their initial velocity (no changing of the velocity (they also pass the boundary particles without any interaction). So I thought, maybe I have to change some parameters. So I wrote a script that tries all possible combinations of kernel, algorithm, density filter and so on. But there are to much possibilities. So I checked only some combinations. The result is the same (zero pressure).

After this I tried to figure out where it comes from. Its causes of the EoS. If rho0 is equal rho, the pressure is zero (it’s the same for all EoS). If I change rho0 the pressure is not zero, but the pressure of all particles is the same, so there is no force depending on the pressure.

It seems to me, that there is no search for neighbor particles. But “h” is big enough to have same neighbors. Is there a common mistake.

The test cases form SPHysics work fine.

Regards

Seb