Hello,
I am using LIGGGHTS to simulate a simple granular flow condition in which at first particles are inserted in a cuboidal space and one side of this cuboid is removed to allow granular flow. But I am not getting the values of kinetic energy, potential energy, coordination number from 'compute' command. Further, the same is not getting shown in Paraview. Please find the code.
atom_style granular
atom_modify map array
boundary f f f
newton off
communicate single vel yes
processors * * *
units si
region reg block -0.01 0.35 -0.01 0.1 -0.01 0.15 units box
create_box 2 reg
neighbor 0.0084 bin
neigh_modify delay 0
#Material properties required for new pair styles
fix m1 all property/global youngsModulus peratomtype 5.e6 1.e9
fix m2 all property/global poissonsRatio peratomtype 0.31 0.3
fix m3 all property/global coefficientRestitution peratomtypepair 2 0.3 0.3 0.3 0.3
fix m4 all property/global coefficientFriction peratomtypepair 2 0.7 0.424 0.424 0.8
fix m5 all property/global coefficientRollingFriction peratomtypepair 2 1.25 1.25 1.25
0.3
#New pair style
pair_style gran model hertz tangential history rolling_friction cdt #Hertzian without cohesion
pair_coeff * *
timestep 0.00001
fix gravi all gravity 9.81 vector 0.0 0.0 -1.0
#the gccm
fix surface1 all wall/gran model hertz tangential history rolling_friction cdt primitive type 2 zplane 0.0
fix wall1 all wall/gran model hertz tangential history rolling_friction cdt primitive type 2 yplane 0.0
fix wall2 all wall/gran model hertz tangential history rolling_friction cdt primitive type 2 yplane 0.09
fix wall3 all wall/gran model hertz tangential history rolling_friction cdt primitive type 2 xplane 0.0
fix wall4 all wall/gran model hertz tangential history rolling_friction cdt primitive type 2 xplane 0.05
#distributions for insertion
fix pts1 all particletemplate/sphere 15485863 atom_type 1 density constant 1450 radius constant 0.00105
fix pdd1 all particledistribution/discrete 32452843 1 pts1 1.0
#region and insertion
region column block 0. 0.05 0. 0.09 0. 0.08 units box
#particle insertion with porosity 0.35
fix ins all insert/pack seed 67867967 distributiontemplate pdd1 &
insert_every once overlapcheck yes all_in yes maxattempt 10000 vel constant 0. 0. -0.5 particles_in_region 30160 &
region column ntry_mc 10000
#apply nve integration to all particles that are inserted as single particles
fix integr all nve/sphere
#output settings, include total thermal energy
compute 1 all erotate/sphere
compute 2 all ke/atom
compute 3 all pe/atom
compute 4 all erotate/sphere/atom
compute 5 all contact/atom
thermo_style custom step atoms ke c_1 vol
thermo 1000
thermo_modify lost ignore norm no
#insert the first particles so that dump is not empty
run 1
dump dmp all custom 1000 post/dump*.shi id type type x y z ix iy iz vx vy vz fx fy fz omegax omegay omegaz c_2 c_3 c_4 c_5
#insert particles
run 20000 upto
unfix ins
unfix wall4
run 200000
Kindly help me with my problem.
Thanks.
Aman
mschramm | Wed, 03/23/2022 - 16:35
Not seeing an issue
Hello,
I ran your script and am getting this information.
The only value that I am not getting anything for is the Potential Energy value. I believe this only keeps track of potentials caused by bonds.
How are you viewing your data?
Aman | Thu, 03/24/2022 - 17:24
Using Paraview
Hello sir,
Thanks for your help. I am unable to get the results from compute. I am using Paraview for the post processing. Please help me.
Thanking You.
Aman.
mschramm | Fri, 03/25/2022 - 18:26
Values in dump
Hello,
Are the values in the dump files?
Are you getting any error messages from paraview?
I see your computes in the my dump files as c_2, c_3, c_4, and c_5 while your c_1 is printed to the thermo output.
When I loaded the dump file into Paraview using the Paraview reader (I have a forked version), there were multiple warnings that the reader did not recognize the values c_2 - c_5 but did report them. (I have since removed the warning message in my forked version for Paraview 5.9.1)
Aman | Thu, 03/31/2022 - 17:18
Can I get values from dump files
Hello sir,
Thanks a lot for your help. Are the values getting reported in dump files?
I am facing the same issue in Paraview as what you are facing. There are multiple warnings and the values of c_2 to c_5 are not shown.
Can I get these values from dump files?
Thanks.
Aman.
mschramm | Thu, 03/31/2022 - 22:27
Just warnings
If you are using the paraview filter to read general liggghts text files, you should be able to see the c_^ variables.
These messages are just warnings (and can be very annoying...).
I have my own fork of the reader and simply commented out the warning message.
pain08 | Wed, 11/02/2022 - 10:54
vtk dump
hello try vtk for the dumps might work something like this
dump dmp all custom/vtk 1000 post/dump*.vtk id type type x y z ix iy iz vx vy vz fx fy fz omegax omegay omegaz c_2 c_3 c_4 c_5