Hi Christoph,
I am testing a simple CFD-DEM case of cyclone separator using cfdemSolverPiso. Before doing the coupling of CFD-DEM, CFD and DEM simulation were tested separately and worked fine. However, when performing CFD-DEM coupling, it seems that the same command " fix insert/stream " in DEM does not work with cfdemPisoSolver.
CFD test:
DEM test:
For pure DEM test, the following command works well for inserting particle stream:
fix ins nve_group insert/stream seed 5330 distributiontemplate pdd1 &
nparticles 20000 particlerate 8000 overlapcheck yes vel constant 0.0 5.0 0.0 &
insertion_face inface extrude_length 0.02
But in CFD-DEM, the solver complains:
...
Reading STL file '../DEM/cycloneMesh.stl'
Reading STL file '../DEM/insertion_face.stl'
Resetting global state of Fix pts1 Style particletemplate/sphere from restart file info
Resetting global state of Fix pts2 Style particletemplate/sphere from restart file info
Resetting global state of Fix pts3 Style particletemplate/sphere from restart file info
Fix particledistribution/discrete (id pdd1): distribution based on mass%:
pts1: d=2.000000e-03 (max. bounding sphere) mass%=50.000000%
pts2: d=4.000000e-03 (max. bounding sphere) mass%=30.000000%
pts3: d=7.000000e-03 (max. bounding sphere) mass%=20.000000%
Fix particledistribution/discrete (id pdd1): distribution based on number%:
pts1: d=2.000000e-03 (max. bounding sphere) number%=92.222894%
pts2: d=4.000000e-03 (max. bounding sphere) number%=6.916717%
pts3: d=7.000000e-03 (max. bounding sphere) number%=0.860389%
Resetting global state of Fix pdd1 Style particledistribution/discrete from restart file info
ERROR: Fix insert/stream (id ins): unknown keyword or wrong keyword order (fix_insert_stream.cpp:107)
...
I suspect that the CFD-DEM solver changed some input parameters implicitly to the defined " fix insert/stream " , but don't know how to debug or fix this issue.
Is there also anybody else faced the same/similar issue ever?
Any tips or recommendation on this issue will be appreciated.
Cheers,
David
keepfit | Mon, 08/05/2013 - 14:22
Attached codes
Here is the DEM code for coupling:
# Cyclone separator CFD-DEM
atom_style sphere
atom_modify map array
boundary f f f
newton off
communicate single vel yes
units si
# block args = xlo xhi ylo yhi zlo zhi
#region reg block -0.25 0.25 -0.35 0.25 -0.5 1.2 units box
#create_box 1 reg
read_restart ../DEM/cyclone.restart
neighbor 0.002 bin
neigh_modify delay 0
#Material properties required for new pair styles
fix m1 all property/global youngsModulus peratomtype 5.e6
fix m2 all property/global poissonsRatio peratomtype 0.45
fix m3 all property/global coefficientRestitution peratomtypepair 1 0.3
fix m4 all property/global coefficientFriction peratomtypepair 1 0.5
fix m5 all property/global k_finnie peratomtypepair 1 1.0
#New pair style
pair_style gran/hertz/history #Hertzian without cohesion
pair_coeff * *
timestep 0.000001 # DEM delta T = 1e-6 , CFD delta T = 1e-4, write interval 0.01s
fix gravi all gravity 9.81 vector 0.0 0.0 -1.0
# Cyclone Mesh
fix cad all mesh/surface/stress file ../DEM/cycloneMesh.stl type 1 wear finnie
fix inface all mesh/surface file ../DEM/insertion_face.stl type 1
fix granwalls all wall/gran/hertz/history mesh n_meshes 1 meshes cad
#distributions for insertion
fix pts1 all particletemplate/sphere 1 atom_type 1 density constant 2000 radius constant 0.001
fix pts2 all particletemplate/sphere 1 atom_type 1 density constant 2000 radius constant 0.002
fix pts3 all particletemplate/sphere 1 atom_type 1 density constant 2000 radius constant 0.0035
fix pdd1 all particledistribution/discrete 321 3 pts1 0.5 pts2 0.3 pts3 0.2
#region and insertion
#group nve_group region reg
#region inReg block 0.16 0.22 -0.23 -0.25 0.85 0.95 units box
#particle insertion
fix ins all insert/stream seed 5330 distributiontemplate pdd1 &
nparticles 20000 particlerate 8000 overlapcheck yes vel constant 0.0 5.0 0.0 &
insertion_face inface extrude_length 0.02
#cfd coupling
fix cfd all couple/cfd couple_every 100 mpi
fix cfd2 all couple/cfd/force
#apply nve integration to all particles that are inserted as single particles
fix integr nve_group nve/sphere
#center of mass
compute centerOfMass all com
#compute total dragforce
compute dragtotal all reduce sum f_dragforce[1] f_dragforce[2] f_dragforce[3]
#screen output
compute 1 all erotate/sphere
thermo_style custom step atoms ke c_1 vol c_centerOfMass[3] c_dragtotal[1] c_dragtotal[2] c_dragtotal[3]
thermo 1000
thermo_modify lost ignore norm no
compute_modify thermo_temp dynamic yes
#insert the first particles so that dump is not empty ../DEM/post
#run 1
dump dmp all custom 10000 ../DEM/postCFDEM/dumpParticle*.liggghts id type type x y z ix iy iz vx vy vz fx fy fz mass omegax omegay omegaz radius
dump dumpstress all mesh/gran/VTK 10000 ../DEM/postCFDEM/dumpWall*.vtk stress wear cad
#run 500000 upto
#unfix ins
run 1
cgoniva | Thu, 10/24/2013 - 17:02
hi,
hi,
when running coupled you cannot use the "&" for line break.
Cheers,
Chris
ebtedaei | Wed, 01/18/2017 - 11:32
Help to simulate cyclone with LIGGGHTS
Hi,
I am a new user for LIGGGHTS. I want to simulate solid particles in cyclone, so please help me about the fallowing subjects:
- I need a in. file. of cyclone.
- To mesh, Will both sections Body and Volume of cyclone be meshed?
Thanks,
Ali
40044600 | Mon, 02/27/2017 - 17:53
Hi,
Hi,
I had the same problem but as Chris has said removing the '&' moved for me.
:)