Moving measure points

artiomc

Hi,

I am modelling sloshing in a tank under sinusoidal translational motion and have a little issue with collecting the required data from the model.
I am new to SPH and DualSPHysics - following the examples in the RUN_DIRECTORY folder I managed to set up an array of points to measure water height, velocity and pressure. The problem is that these points are fixed to the global frame of reference, so when the tank moves, every measurement is taken at a different location within the tank. My question is whether it is possible to set up moving points (so that they move along with the tank) or "attach" them to a moving object so that they remain fixed relative to the tank?

Alex

In new versions we will include the option of reading positions to compute magnitudes from a file where position is changing along time.

But now you can use -particlesmk:20
If you create drawpoint with mk 20 as point of the wall of the sloshing tank. You will be able to compute for example pressure at that point during simulation since you only need to specif mk=20 moving or not

Regards

artiomc

Thanks Alex for a quick and helpful reply.

I am trying to solve another problem, with no success so far. After 15s simulation I discovered that the number of particles reduced drastically. From ~2500 particles I was left with only 900, that is two thirds of fluid gone! When I run .bat file it gives a message "Particles out: X (total: Y)" - the further it gets the more particles disappear (none disappeared in first few seconds).

What could be the cause of this and how can it be solved?
I doubt that fluids go beyond domain limits. I attempted to create another, larger box within which the tank would move - still same result. Plus the fact that no particles disappear in first few seconds of simulation.

Help?

Alex

Particles dissapear when particles leave the limits of domain but also when particles reach values of density out the range (700-1300)

Regards