Temp is very high

raguelmoon's picture
Submitted by raguelmoon on Wed, 04/20/2011 - 04:59

Hi,
I am doing simulation and printing out temp of granular particles but it displays very high value, I dont understand its meaning. Can anybody guide me?
Value output on screen (in fifth column) :

61000 2360 0.0032032676 0.00055331777 3.8438666e+16 0.001189728
62000 2360 0.0067480441 0.0004580142 7.3734852e+16 0.001189728
63000 2360 0.0094283732 0.00042055652 1.0077762e+17 0.001189728
64000 2360 0.0098094931 0.00042700973 1.047434e+17 0.001189728

I used these commands for computation of temp.

compute T all temp/sphere
and then:
thermo_style custom step atoms ke c_1 c_T vol

Thanks,
Ram

ckloss's picture

ckloss | Wed, 04/20/2011 - 08:10

This is not macroscopic temperature, but temperature in a molecular dynamics / statistical mechanics sense - probably not what you want.
See heat_gran examples and doc for fix heat/gran for how to output per-particle (macroscopic) temperature and total thermal energy

Christoph

raguelmoon's picture

raguelmoon | Wed, 04/20/2011 - 12:28

Hi Christoph,
Is there no way of outputting thermal temperature contributed by collisions of particles during wiggle, shake?
Thanks,
Ram

Ram

ckloss's picture

ckloss | Wed, 04/20/2011 - 12:54

There is currently no model for temperature change due to collisions. I guess for most applications this is negligibly. If you need this, you would have to code it.
If you need "granular temperature" in the sense of statistical mechanics, compute temp/sphere is what you want

Christoph