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# -*- encoding=utf-8 -*-
#*************************************************************************
# Copyright (C) 2019 by Robert Caulk *
# rob.caulk@gmail.com *
# *
# This program is free software; it is licensed under the terms of the *
# GNU General Public License v2 or later. See file LICENSE for details. *
#*************************************************************************/
#
# Script demonstrating the use of ThermalEngine by comparing conduction
# scheme to analytical solution to Fourier (rod cooling with constant
# boundary conditions). See details in:
#
# Caulk, R., Scholtes, L., Kraczek, M., Chareyre, B. (In Print) A
# pore-scale Thermo-Hydro-Mechanical coupled model for particulate systems.
# Computer Methods in Applied Mechanics and Engineering. Accepted July 2020.
#
from yade import pack
from yade import timing
import numpy as np
import shutil
timeStr = time.strftime('%m-%d-%Y')
num_spheres = 1000 # number of spheres
young = 1e6
rad = 0.003
mn, mx = Vector3(0, 0, 0), Vector3(1.0, 0.008, 0.008) # corners of the initial packing
thermalCond = 2. #W/(mK)
heatCap = 710. #J(kg K)
t0 = 400. #K
r = rad
k = 2 * 2.0 * r # 2*k*r
Cp = 710.
rho = 2600.
D = 2. * r
m = 4. / 3. * np.pi * r**2 / rho
# macro diffusivity
thermalDiff = 6. * k / (D * np.pi * Cp * rho)
identifier = '-conductionVerification'
if not os.path.exists('VTK' + timeStr + identifier):
os.mkdir('VTK' + timeStr + identifier)
else:
shutil.rmtree('VTK' + timeStr + identifier)
os.mkdir('VTK' + timeStr + identifier)
if not os.path.exists('txt' + timeStr + identifier):
os.mkdir('txt' + timeStr + identifier)
else:
shutil.rmtree('txt' + timeStr + identifier)
os.mkdir('txt' + timeStr + identifier)
shutil.copyfile(sys.argv[0], 'txt' + timeStr + identifier + '/' + sys.argv[0])
O.materials.append(FrictMat(young=young, poisson=0.5, frictionAngle=radians(3), density=2600, 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)
O.bodies.append(pack.regularOrtho(pack.inAlignedBox(mn, mx), radius=rad, gap=-1e-8, material='spheres'))
print('num bodies ', len(O.bodies))
ThermalEngine = ThermalEngine(dead=1, label='thermal')
newton = NewtonIntegrator(damping=0.2)
intRadius = 1
O.engines = [
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(aabbEnlargeFactor=intRadius), Bo1_Box_Aabb()]),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom(interactionDetectionFactor=intRadius),
Ig2_Box_Sphere_ScGeom()], [Ip2_FrictMat_FrictMat_FrictPhys()], [Law2_ScGeom_FrictPhys_CundallStrack()],
label="iloop"
),
FlowEngine(dead=1, label="flow", multithread=False),
ThermalEngine,
GlobalStiffnessTimeStepper(active=1, timeStepUpdateInterval=100, timestepSafetyCoefficient=0.8),
#triax,
VTKRecorder(iterPeriod=500, fileName='VTK' + timeStr + identifier + '/spheres-', recorders=['spheres', 'thermal', 'intr'], dead=1, label='VTKrec'),
newton
]
#goal = -1e5
#triax.goal1=triax.goal2=triax.goal3=goal
for b in O.bodies:
if isinstance(b.shape, Sphere):
b.dynamic = False
# we only need flow engine to detect boundaries, there is no flow computed for this
flow.dead = 0
thermal.dead = 0
thermal.conduction = True
thermal.thermoMech = False
thermal.advection = False
thermal.fluidThermoMech = False
thermal.solidThermoMech = False
thermal.fluidConduction = False
thermal.bndCondIsTemperature = [1, 1, 0, 0, 0, 0]
thermal.thermalBndCondValue = [0, 0, 0, 0, 0, 0]
thermal.tsSafetyFactor = 0
thermal.particleDensity = 2600
thermal.particleT0 = t0
thermal.particleCp = heatCap
thermal.particleK = thermalCond
thermal.particleAlpha = 11.6e-3
thermal.useKernMethod = False
timing.reset()
#ThermalEngine.dead=0
flow.updateTriangulation = True
O.dt = 1.
O.dynDt = False
flow.emulateAction()
flow.dead = 1
#triax.goal2=-11000
def bodyByPos(x, y, z):
cBody = O.bodies[1]
cDist = Vector3(100, 100, 100)
for b in O.bodies:
if isinstance(b.shape, Sphere):
dist = b.state.pos - Vector3(x, y, z)
if np.linalg.norm(dist) < np.linalg.norm(cDist):
cDist = dist
cBody = b
print('found closest body ', cBody.id, ' at ', cBody.state.pos)
return cBody
# solution to the heat equation for constant initial condition , BCs=0, and using series for approx
def analyticalHeatSolution(x, t, u0, L, k):
ns = np.linspace(1, 1000, 1000)
solution = 0
for i, n in enumerate(ns):
integral = (-2. / L) * u0 * L * (np.cos(n * np.pi) - 1.) / (n * np.pi)
solution += integral * np.sin(n * np.pi * x / L) * np.exp((-k * (n * np.pi / L)**2) * t)
return solution
# find 10 bodies along x axis
axis = np.linspace(mn[0], mx[0], num=11)
axisBodies = [None] * len(axis)
axisTrue = np.zeros(len(axis))
for i, x in enumerate(axis):
axisBodies[i] = bodyByPos(x, mx[1] / 2, mx[2] / 2)
axisTrue[i] = axisBodies[i].state.pos[0]
np.savetxt('txt' + timeStr + identifier + '/xdata.txt', axisTrue)
print("Axis length used for analy ", max(axisTrue) - min(axisTrue))
from yade import plot
## a function saving variables
def history():
plot.addData(
t=O.time,
i=O.iter,
temp1=axisBodies[0].state.temp,
temp2=axisBodies[1].state.temp,
temp3=axisBodies[2].state.temp,
temp4=axisBodies[3].state.temp,
temp5=axisBodies[4].state.temp,
temp6=axisBodies[5].state.temp,
temp7=axisBodies[6].state.temp,
temp8=axisBodies[7].state.temp,
temp9=axisBodies[8].state.temp,
temp10=axisBodies[9].state.temp,
temp11=axisBodies[10].state.temp,
AnalyTemp1=analyticalHeatSolution(0, O.time, t0, mx[0], thermalDiff),
AnalyTemp2=analyticalHeatSolution(axisBodies[1].state.pos[0], O.time, t0, mx[0], thermalDiff),
AnalyTemp3=analyticalHeatSolution(axisBodies[2].state.pos[0] - min(axisTrue), O.time, t0,
max(axisTrue) - min(axisTrue), thermalDiff),
AnalyTemp4=analyticalHeatSolution(axisBodies[3].state.pos[0] - min(axisTrue), O.time, t0,
max(axisTrue) - min(axisTrue), thermalDiff),
#bndFlux1 = thermal.thermalBndFlux[0],
#bndFlux2 = thermal.thermalBndFlux[1]
AnalyTemp5=analyticalHeatSolution(mx[0], O.time, t0, mx[0], thermalDiff)
)
plot.saveDataTxt(
'txt' + timeStr + identifier + '/conductionAnalyticalComparison.txt',
vars=('t', 'i', 'temp1', 'temp2', 'temp3', 'temp4', 'temp5', 'temp6', 'temp7', 'temp8', 'temp9', 'temp10', 'temp11')
)
#plot.addData(e22=-triax.strain[1],t=O.time,s22=-triax.stress(2)[1],p=flow.MeasurePorePressure((0.5,0.5,0.5)))
O.engines = O.engines + [PyRunner(iterPeriod=500, command='history()', label='recorder')]
##make nice animations:
#O.engines=O.engines+[PyRunner(iterPeriod=200,command='flow.saveVtk(withBoundaries=False)')]
VTKrec.dead = 0
from yade import plot
plot.plots = {'t': (('temp4', 'k-'), ('temp3', 'r-'), ('AnalyTemp4', 'k--'), ('AnalyTemp3', 'r--'))} #
#plot.plots={'t':(('bndFlux1','k-'),('bndFlux2','r-'))} #
plot.plot()
O.saveTmp()
O.timingEnabled = 1
from yade import timing
print("starting oedometer simulation")
O.run(200, 1)
timing.stats()
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