how to calculate voidage using voronoi package

Submitted by xiaobaishu67 on Wed, 03/11/2015 - 15:47

Dear users,
Do anybody know how to use voronoi package? I compiled it in my liggghts, but it didn't work. I want to calculate the voidage. or is there any other command to calculate void ratio?

ckloss's picture

ckloss | Mon, 03/16/2015 - 11:22

Hi,

I myself did not try the voronoii package, but I think it should work. Alternatively, there is fix ave/euler and dump euler/vtk. There is no doc for it so you'll have to look into the source code

Christoph

nasato | Mon, 03/16/2015 - 13:19

Calculate Voronoi Tesselation in LIGGGHTS:

1 – Add the following command lines to your input script (works also for a poly-disperse distribution):

compute VoroRadius all property/atom radius
variable r2 atom c_VoroRadius
compute voro all voronoi/atom radius v_r2

2 – Add the following command to the dump/custom to dump the Voronoi cell volume:

c_voro[1]
Ps.: See compute_voronoi_atom.html in the LIGGGHTS doc folder for other possible information that can be dumped.

Visualize void fraction in Paraview

1 – Open results files (after using LPP) in Paraview and add a calculator to the particle information:
Filters > Data Analysis > Calculator

2- Calculate particle volume: in “Result Array Name” insert “volume”. In the blank line below insert the expression:
(4/3)*3.14159265*radius^3

3 – Calculate void fraction: Add a new calculator. In “Result Array Name” insert VoidFraction. In the blank line below insert the expression:
(voro-volume)/voro

4 – Visualize void fraction: insert a Delaunay 3D triangulation. Go to:
Filters > Alphabetical > Delaunay 3D

5 – You can leave settings as default and click Apply. In coloring select VoidFraction. This should created a Volumetric data field of Void Fraction.

Cheers,

Nasato

andybond13 | Sun, 03/26/2017 - 20:02

I'm running LIGGGHTS-PUBLIC 3.6.0. I've followed your directions, Nasato, but Liggghts segfaults at the first timestep that the dump/custom containing c_voro[1] is called.

K.cheng | Sat, 05/23/2015 - 09:40

Hi,xiaobaishu67:
I want to caldulate local voidage and i see your problem on the CFDEM forum . could you tell me how i can compile voronoi package? i also want to know whether you have used " compute atom/voronoi" command successfully . From your nickname , i guess you are Chinese and i am also Chinese . This is my qq: 374390895. please add me as friends and i would like to ask some questions.
Thanks,
K.cheng

qbbfjx | Thu, 09/20/2018 - 02:32

Hi, K.cheng

I bet you have figured out how to compile voronoi and used the compute voronoi/atom function successfully. Could you please help me with it?

Thanks.

Rachel | Fri, 08/17/2018 - 09:32

Have anyone sucessufully installed the voronoi package? I still don't know how to install this function. Could anyone please give me any clues?

Best,
Rachel

qbbfjx | Thu, 09/20/2018 - 06:04

Hi Rachel

I have the same issue. I followed the instructions to compile voro++ but when I ran simulation, it showed error which is 'invalid compute style'.
Have you figured it out?

Thanks.
Binbin

Jeff_DONG | Wed, 02/20/2019 - 03:22

download and compile Voronoi package before building LIGGGHTS would solve this problem