WARNING: time-step is 28.194306 % of rayleigh time (../fix_check_timestep_gran.cpp:200)
WARNING: time-step is 14.155515 % of hertz time (../fix_check_timestep_gran.cpp:208)
I can't help me solving this problem with help of other discussions on forum related to this concern. Can anyone kindly help me with this problem in simpler way..?
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richti83 | Thu, 08/09/2018 - 20:16
You need to use a smaller
You need to use a smaller timestep or bigger particles or smaller youngs modulus.
https://www.cfdem.com/media/DEM/docu/fix_check_timestep_gran.html
Fabeeha | Fri, 08/10/2018 - 21:04
Simulation is running very slow
Thank you so much sir,, I'am using timestep of 10^-6, this reduced the rayleigh time exceed to approx 5-6 %, and Hertz time exceed to 2-3 % of timestep, but simulation is very slow now and at each time step only 100 particles are being inserted for my available simulation PC resources.
Kindly tell me that how can I improve simulation efficiency?
Can larger meshing help me with this? And how can i play with other parameters to improve simulation efficiency reduce processing time?
Thanking you in anticipation.
paul | Mon, 08/13/2018 - 20:45
Tell us more about your case.
Tell us more about your case. How have you divided the domain among the cores? How many particles in the end? Do you insert every time step - which is a bad idea btw - or could you live w/ inserting less frequently.
Inserting can be accelerated by choosing a larger region for it, especially if you pack to high densities (/low porosities).
You can usually get away with a timestep of 20% the Rayleigh time.