Simulation time vs Physical Time

Theo_Score's picture
Submitted by Theo_Score on Mon, 07/24/2017 - 02:29

Hi All,

I have a physical system (fully loaded material bin with stones) which physically discharges the material contents in 95 seconds.

I have the same system in DEM (same physical dimensions for the geometry and particle sizes), with a time step of 1.0E-6 sec. The DEM system completely discharges in 20 seconds (20.0E6 time steps).

I mean to ask if there is a relationship between physical discharge time and simulation time. Is there anything wrong with this simulation? Does the DEM system really need to discharge in 95 seconds as in physical system?

Thank you.

Forums:

jsams | Mon, 07/24/2017 - 06:25

Hi Theo_Score,

If your simulation is replicating the exact physical process then you should end up with identical discharge times. You might have to adjust some of your material parameters if you're using spherical particles or multispheres in the simulation. I suggest you start with having a closer look at the sliding friction coefficient and rolling resistance coefficient in your simulations as they can have a big effect on the discharge time.