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[Othman Sh <question688685@xxxxxxxxxxxxxxxxxxxxx>]

Question #688685 on Yade changed:
https://answers.launchpad.net/yade/+question/688685

    Status: Answered => Open

Othman Sh is still having a problem:
It make sense to me. But when I tried it still I got errors. So I went
back to the oedometer code [1] and removed the triax part and reduced
the code to just permeability. I realized that it will work until I
remove the walls surrounding the packing. If I remove the walls and set
flow.boundaryUseMaxMin=[1,1,1,1,1,1] then it will give me this error

negative volume for an ordinary pore (temp warning, should still be safe)
*** stack smashing detected ***: <unknown> terminated
Aborted (core dumped)

Any idea why?


So now the code below  with the aabbWalls works fine (although the averageVelocity() results is super high!). 

Do you think that having a box (6 walls) surrounding a cylindrical
sphere packing will give different results than if the cylindrical
sphere packing was surrounded by a cylindrical wall?


Thanks,
Othman

[1] https://github.com/yade/trunk/blob/master/examples/FluidCouplingPFV/oedometer.py
---------------------------------------------------
# -*- coding: utf-8 -*-


from __future__ import print_function
from builtins import range
from yade import pack, ymport
radiuscyl=.08
heightcyl=.25
dP=4e3 #Pa
visc=1e-3 #Pa.sec
density=1000 #kg/m3
g=9.81 #m/s2

young=1e6

mn,mx=Vector3(0.12051283763637842,0.12120598296516694,0.000018575942022891825),Vector3(0.2788652537183969,0.27855505606930653,0.24827692256149453)
# corners of the box that contain the packing. Obtained from aabbExtrema

O.materials.append(FrictMat(young=young,poisson=0.2,density=1900,label='spheres'))
O.materials.append(FrictMat(young=young,poisson=0.5,frictionAngle=0,density=0,label='walls'))
walls=aabbWalls([mn,mx],thickness=0,material='walls')
wallIds=O.bodies.append(walls)
yade.qt.View()

############################# spheres #############################
sp=pack.SpherePack()
sp.makeCloud((0,0,0),(.4,.4,2),rMean=0.0083,rRelFuzz=0.1,seed=1)	
### cylinder extraction 										
pred=pack.inCylinder((.2,.2,0),(.2,.2,heightcyl),radiuscyl) 						
spFilter=filterSpherePack(pred,sp,Material=Material, returnSpherePack=True)				
spFilter.toSimulation()

Height=max(utils.aabbDim())

#Fix all particles in their positions. No deformation
for i in O.bodies:
	i.state.blockedDOFs='xyzXYZ'

O.engines=[
	ForceResetter(),
	InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Box_Aabb()]),
	InteractionLoop(
		[Ig2_Sphere_Sphere_ScGeom(),Ig2_Box_Sphere_ScGeom()],
		[Ip2_FrictMat_FrictMat_FrictPhys()],
		[Law2_ScGeom_FrictPhys_CundallStrack()],label="iloop"
	),
	FlowEngine(dead=1,label="flow"),#introduced as a dead engine for the moment, see 2nd section
	GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=100,timestepSafetyCoefficient=0.8),
	NewtonIntegrator(damping=0.2)
]


#B. Activate flow engine and set boundary conditions in order to get permeability
flow.dead=0
flow.useSolver=3
flow.permeabilityFactor=1
flow.viscosity=visc
flow.bndCondIsPressure=[0,0,0,0,1,1]
flow.bndCondValue=[0,0,0,0,0,dP]
flow.boundaryUseMaxMin=[0,0,0,0,1,1]
O.dt=0.1e-8
O.dynDt=False

O.run(1,1)

Q=max(flow.averageVelocity())
Permeability=abs((density*g*Q*Height)/dP)
print ("average velocity: ",Q, "Permeability m/s: ",Permeability,"Permeability in/hr: ", Permeability*141732)

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