Visualisation of dam break with 1, 10, 100 million particles
I have uploaded to a YouTube playlist several short videos (20 sec) of the dam break simulation run with 1, 10, 100 million fluid particles. The test case is the 3D dam break from the main suite of examples in DualSPHysics 4.4.003 (10-04-2019).
The videos show the particle positions, the velocity field and the density field. Thanks to the post-processing scripts in DualSPHysics toolbox, I have used the two ParaView rendering modes particles and surface.
I have taken the default XML file and changed the particle spacing in order to achieve the desired particle count, and then let it go. The simulations have been run in double precision.
particle spacing and number of fluid particles:
dp="0.00200" Nfp= 10,020,000
dp="0.00250" Nfp= 5,126,400
dp="0.00425" Nfp= 1,026,480
dp="0.00450" Nfp= 882,524
dp="0.00500" Nfp= 644,300
Clearly, simulations should converge to the experimental evidence. So it should not be taken for granted that the particle spacing is the sole parameter to play around with in order to obtain an accurate simulation. I might release more information on validation and on compute performance at a later time.
Nonetheless, this visualisation exercise already shows the dramatic differences that a modeller comes across when the particle count increases, which is technically possible thanks to ever more powerful GPUs. Hope this helps us appreciate the capabilities of SPH and DualSPHysics as well as the care needed in modelling fluid flows appropriately.
For a sneak preview: