Sediment size

simking

Hello,

Now, I'm running '11_CASEMULTIPHASE' 3d case. In this case, how can i control the sediment size for sediment phase? because, size of sediment particles can affect the sediment transport. is it possible that 'dp' is sediment particle size? or How can I control the sediment size?

Thank you,

Alex

This version of the code uses uniform particle size "dp", so that is the initial particle distance you can define for all particles to compute "h", "mass" and "volume".

Regards

gfourtakas

Hi,

This is a very difficult question with a very simple answer in therms of the sediment transport model, I will try to be short and simple:

as Alex pointed out the dp is constant and uniform etc etc, that is the computational node (i.e. particle) size - it is a numerical quantity and should not be confused with the particle size.

The sediment model herein, examines the sediment as a continuum (not DEM) thus the sediment mean dia (d50) is not defined explicitly.
The behaviour of the sediment is controlled by its yield strength (and some cohesion parameter if you wish) and its rheological properties that can be changed in the xml file, the sediment pickup is sorely dependant on the shear characteristics of the continuum (more or less, see doi: 10.1002/fld.4026).

Regards,
George

qiaochengcn

Yes, just as Fourtakas said, the particles in SPH are not the particles in real world. There are no relation directly between them even. The particles in SPH is a tool to discrete the computational domain, and the dp is a scale for discreting.
Under the continuum frame, whether the influence of real world particle size can be expressed, determined by the rheology rules employed in the numerical modelling. If the effects of particles size included by the rheological rule, the results from the modelling will different according to the parameter of particle size. For example the mu rheological rule.

Regards

Qiao Cheng