# variable particle diameter

hello,

How do we specify particle diameter in the Def file? The examples I have come across only uses the dp as the interparticle distance. Is there any tutorial?

Also, Can we use variable particle diameter in the same simulation model?

Thanks

## Comments

What do you mean with particle diameter?

Our preprocessing tool, named GenCase, will create INITIALLY particles in the nodes of cartesian grid with space "dp", so that we use this initial particle distance to create particles.

In addition, we define our kernel distance using the smoothing lenght "h". In the case of a Wendland kernel, we have defined our kernel support for "2h".

Finally, we have defined "h" as function of "dp" with h=sqrt(2)*dp (in 2D), but we have also included a parameter to control the size of the kernel using h=coefh*sqrt(2)*dp....

Hope that this helps

Hello,

My colleague recently tested some commercial sph codes like pronLab, and there they have the option to choose particle diameter..May be they are doing in the background what you are describing, but making it easier for the front end engineer to deal with paricle size which in the background refers to the dp?

In preonLab, he has used different particle sizes so that the gear teeth interspace can be wetted with fluid of smaller particle size and over all they use bigger particle size. How a scenario like that will be handled by dualsphsycis? Can it use variable dp? I will try to get more info from preonlab side. i dont have their user manual yet.

Variable resolution has not been implemented in the online source code of DualSPHysics, so sorry.