Hi everyone,
I've been running a simulation that uses a hybrid granular/molecular style, and performing the integration with a "fix rigid molecule". Once these aggregates have settled, I then heat the lower boundary and want to study the heat flow through this material.
To speed things up, I would like to stop the newtonian integration at a certain point and just continue with pure thermal calculations. I tried to do this by unfixing the "rigid molecule" fix, which works well and I get good thermo output, although the speed-up wasn't as fast as I had hoped (given that the nearest neighbour list should now be fixed etc.). Is there any way I can improve this? Would fix freeze help, or hinder?
Any suggestions welcome! :)
Thanks, Mark
msbentley | Sat, 08/20/2011 - 11:38
OK, that was a silly question...
... I can of course just increase the timestep since it is no longer constrained by particle motion.. :)
ckloss_ | Sun, 08/21/2011 - 22:27
no, the question is not silly
no, the question is not silly at all :-) Well there is at least one more thing you can do: "neigh modify once yes"
Currently the heat transfer model is reading the neighlist from pair gran directly so it cannot work without it, but it would be possible to modify it so that it requests a list on its own, which would not be slower but would enable the heattransfer to work with pair gran.
Also, you should be aware that the contact area varies with young's modulus, so you should maybe gradually increase Y after generating the packing before deactivating integration
Cheers, Christoph
anandmds | Mon, 01/18/2016 - 11:08
Thermal and dyanmic simulation
Hey, I'm doing a similar simulation, where I set a high temperature to a top particle, and view its dissipation through the bed. Only that, I am also vibrating the base of the bed and now I want to study the effects. I am trying to increase the timestep from 0.0001 to 0.001, but the simulation is overlooking the "set" command used to set the temperature to the top region, and also my computer is hanging after the simulation starts. Something is going wrong. Please help
regards
Anand