Re: [Yade-users] [Question #697195]: How to set the PeriodicFlowEngine
Question #697195 on Yade changed: https://answers.launchpad.net/yade/+question/697195 Status: Answered => Solved Zhicheng Gao confirmed that the question is solved: Thanks Bruno Chareyre, that solved my question. -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #697195]: How to set the PeriodicFlowEngine
Question #697195 on Yade changed: https://answers.launchpad.net/yade/+question/697195 Bruno Chareyre proposed the following answer: As the name suggests, PeriodicFlowEngine is for periodic (no-)boundary condition. So no it is not really a "boundary" value problem. It is a periodic field problem. flow.pressureForce=True will compute the drag forces (from both pressure and viscous stress) resulting from macroscopic sliding velocity between the two phases. The other flags are related to lubrication forces: short range pair interactions playing against the relative movement of particles. These forces were added on the top of the drag forces _after_ Catalano 2011. See [2,3] [2] https://link.springer.com/content/pdf/10.1007/s10035-015-0560-6.pdf [3] https://www.sciencedirect.com/science/article/pii/S0032591020305064 Bruno -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #697195]: How to set the PeriodicFlowEngine
Question #697195 on Yade changed:
https://answers.launchpad.net/yade/+question/697195
Zhicheng Gao posted a new comment:
Dear Bruno,
Thank you for your response. In my mind, the flow problem is a boundary value
problem, so the PeriodicFlowEngine should get the position and value of the
boundary. I have read the documentation on PeriodicFlowEngine, I don’t know if
my understanding is wrong. In my opinion, boundaryUseMaxMin is used to set the
boundary position. The default Boolean vector of boundaryUseMaxMin is true on
six faces, which means using the max-min coordinates of X, Y, and Z to add
spheres as the boundary. Otherwise, the wall position is used. I saw the
related problem in Answer #3 in
https://answers.launchpad.net/yade/+question/688195.
another question, I have read your paper 'Pore-Scale Modeling of Viscous
Flow and Induced Forces in Dense Sphere Packings', in that paper, the
total force generated on one particle by the fluid includes the effects
of absolute pressure and viscous stress. So I set
flow.pressureForce=True, flow.viscousShear=True,
flow.viscousNormalBodyStress=True, flow.viscousShearBodyStress=True,
flow.normalLubrication=True, flow.shearLubrication=True. Is that
correct? The complete code looks like this:
from yade import pack,qt,utils,ymport
from yade import export
from yade import timing
from yade import plot
from builtins import range
import numpy
import time
from math import *
O.load('prova.xml')
num_spheres=5000
young=750.e6
finalFricDegree = 0.35
graindensity=2600.0
poisson=0.17
en=0.9
sigmaIso=-150.e3
radiusR=0.001/2.
D50=radiusR*2.0
#O.materials.append(FrictViscoMat(young=young,poisson=poisson,frictionAngle=compFricDegree,density=graindensity,betan=0.0336,label='spheres'))
triax=PeriTriaxController(
dynCell=True,
mass=0.2,
goal=[sigmaIso,sigmaIso,sigmaIso],
stressMask=7,
maxStrainRate=[0.0001,0.0001,0.0001],
label='triax')
newton=NewtonIntegrator(damping=0.1)
O.engines=[
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb()]),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom()],
[Ip2_FrictViscoMat_FrictViscoMat_FrictViscoPhys()],
[Law2_ScGeom_FrictViscoPhys_CundallStrackVisco(traceEnergy=True)]
),
PeriodicFlowEngine(dead=1,label="flow"),
GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=100,timestepSafetyCoefficient=0.5),
triax,
newton
]
while 1:
O.run(1000, True)
unb=unbalancedForce()
if unb<0.1:
break
triax.dead=0
flow.dead=0
flow.pressureForce=True
flow.viscousShear=True
flow.viscousNormalBodyStress=True
flow.viscousShearBodyStress=True
flow.normalLubrication=True
flow.shearLubrication=True
flow.defTolerance=0.1
flow.meshUpdateInterval=200
flow.useSolver=3
flow.permeabilityFactor=1
flow.viscosity=0.001
flow.bndCondIsPressure=[0,0,0,0,1,1]
flow.bndCondValue=[0,0,0,0,0,0]
GlobalStiffnessTimeStepper.dead=True
O.dt=min(0.5*PWaveTimeStep(),0.5*1./1200.*pi/flow.viscosity*graindensity*(D50/2.)**2)
O.dynDt=False
O.run(10,1)
while 1:
O.run(5000, True)
unb=unbalancedForce()
if unb<0.0001:
if O.cell.velGrad[0,1]<0.01:
O.cell.velGrad=O.cell.velGrad+Matrix3(0,0.001,0, 0,0,0, 0,0,0)
O.dt=min(0.5*PWaveTimeStep(),0.5*1./1200.*pi/flow.viscosity*graindensity*(D50/2.)**2)
if O.cell.velGrad[0,1]>0.01:
break
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Re: [Yade-users] [Question #697195]: How to set the PeriodicFlowEngine
Question #697195 on Yade changed: https://answers.launchpad.net/yade/+question/697195 Status: Open => Answered Bruno Chareyre proposed the following answer: Hi, 1/ No, if it is periodic there is just no walls. You simply impose a macroscopic pressure gradient. (well... it really depends what you are trying to achieve, not clear from the question). 2/ As for "should I set", it really depends on what you are trying to simulate, so I cannot answer. Bruno -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
[Yade-users] [Question #697195]: How to set the PeriodicFlowEngine
New question #697195 on Yade: https://answers.launchpad.net/yade/+question/697195 I build the scene in the periodic boundary, so there are no walls. Does that mean I should use flow.boundaryUseMaxMin= [1,1,1,1,1,1], given that the label of PeriodicFlowEngine is set to flow. Another question, I have read [1], the total force generated on one particle by the fluid includes the effects of absolute pressure and viscous stress. Thus, should I set flow.pressureForce=True, flow.viscousShear=True, flow.viscousNormalBodyStress=True, flow.viscousShearBodyStress=True, flow.normalLubrication=True, flow.shearLubrication=True? -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #697195]: How to set the PeriodicFlowEngine
Question #697195 on Yade changed: https://answers.launchpad.net/yade/+question/697195 Zhicheng Gao gave more information on the question: [1]https://link.springer.com/article/10.1007/s11242-011-9915-6 -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
