GAUSSIAN particle distribution

Submitted by rob1 on Fri, 07/22/2016 - 11:57

Good morning,

I would like to create a gaussian distribution of particle sizes, but in particletemplate/sphere only a 'constant' radius is permitted.
What do you suggest?

Thanks a lot and have a nice day,
rob1

hunger's picture

hunger | Mon, 07/25/2016 - 09:53

Hi rob1,

some time ago I tested the possibilities for particle insertion and all combinations for radius and density distributions worked fine for me. Here is my code, maybe it helps you (just replace the variables ${rho} and ${r1} with your density and radius values and comment/uncomment the regarding code lines):

# Distributions and template for insertion
fix pts1 all particletemplate/sphere 1 atom_type 1 density constant ${rho} radius constant ${r1} # const density, const radius
#2 fix pts1 all particletemplate/sphere 1 atom_type 1 density constant ${rho} radius uniform number 0.10 0.14 # const density, uniform radius
#3 fix pts1 all particletemplate/sphere 1 atom_type 1 density constant ${rho} radius gaussian number 0.12 0.025 # const density, gaussian radius

#4 fix pts1 all particletemplate/sphere 1 atom_type 1 density uniform 200. 300. radius constant ${r1} # unitform density, const radius
#5 fix pts1 all particletemplate/sphere 1 atom_type 1 density gaussian 200. 20. radius constant ${r1} # gaussian density, const radius

#6 fix pts1 all particletemplate/sphere 1 atom_type 1 density uniform 200. 400. radius uniform number 0.08 0.1 # unitform density, uniform radius

Best regards
Harald

deepakpawar.2310 | Thu, 12/14/2017 - 07:38

Any comment on the follwoing error , i am using the following command for particle distribution

# Particle distributions
fix pts1 all particletemplate/sphere 15485863 atom_type 1 density constant 2500 radius gaussian number 0.001 0.0001 # mu (mean) and sigma (standard devation)
fix pdd1 all particledistribution/discrete 15485867 1 pts1 1.0

ERROR: Fix particletemplate/sphere (id pts1): invalid radius random style (../fix_template_sphere.cpp:199)
(../fix_template_sphere.cpp:199)

hunger's picture

hunger | Thu, 07/28/2016 - 08:27

Interesting!

The code lines I have posted above worked fine for me (using LIGGGHTS 3.3.1). Also in Paraview the results for both density and radius distributions seem to be as expected.
I have checked my simulation again, it still works fine. I have used a particledistribution with exactly one particle template, maybe this is somehow connected?

However, rob1 already gets an error message when defining the particletemplate itself ...

Best regards
Harald

rob1 | Fri, 07/29/2016 - 18:44

Nice, I will try.
Excuse me, why are you using a "radius uniform" before gaussian? May it be removed?

Thanks,
rob1

hunger's picture

hunger | Sun, 07/31/2016 - 10:55

yes, just pick the line you want to use. These are just several runs that I have tested, in each run I comment and uncomment the corresponding lines.

Best regards
Harald