Post on 04-Jul-2020
Ch 01 Introduction to complex fluids
Solid ------------------- Liquid
Ideal Solid ----- Most Materials ----- Ideal Fluid
Elastic ----- Viscoelastic ----- Viscous
Strain
time0
Stress
time0
Stress
time0
Stress
time0
Solid Like ---------- Liquid LikeIdeal Solid ----- Most Materials ----- Ideal FluidPurely Elastic ----- Viscoelastic ----- Purely Viscous
γτ G= γητ &=
( ) ( )( )T Tpp p p pWe u u u u u
tτ
τ τ τ τ β∂⎛ ⎞
+ + ⋅∇ − ∇ ⋅ − ⋅∇ = ∇ + ∇⎜ ⎟∂⎝ ⎠
( )2
, , , ,
Re (1 )
0
pp
p
f
u u u p ut
u
τ λ β η
β
τ
τ
=
∂⎛ ⎞+ ⋅∇ = −∇ +∇⋅ + − ∇⎜ ⎟∂⎝ ⎠∇ ⋅ =
u
Time-dependent Viscoelastic Behavior
• Old Testament Prophetess who said :"The Mountains Flowed before the Lord"
• Everything Flows if you wait long enough!
• Deborah Number, De - The ratio of a characteristic time of a material (τ) to a characteristic time of the process (Τ)
De = τ/Τ
Rheology
• The science of flow and deformation of matter (complex fluids)
• Viscoelastic• Deborah number• Processing technology
De = τ/Τ
Mathematical rheologyMathematical theology
ABS
ABS (Acrylonitrile-Butadiene-Styrene)
Particle size
Gel content
Graft ratio
Impact strength
Hard-ness
Tensile strength
Flexural strength
VST gloss
ABS-4 3075 86 42 26.7 96.4 402 582 93.7 103.9
ABS-5 3100 82 69 24.1 95.3 393 567 95.1 101.7
G’ and η* of ABS
0.01 0.10 1.00 10.00 100.00 1000.00FREQUENCY
100
1000
10000
100000G
',VIS
CO
SIT
Y
ABS-4
ABS-5
G’ vs. graft ratio
20 40 60 80 100 120Graft ratio
10
100
1000
10000
100000
G' a
t w=0
.1
Sheet grade ( ABS)
• : , • Sheet (gel)• 1 test resin 3• Test - Claim•
••• ???
Competition with HIPS
• ABS,HIPS • ABS , HIPS• : ABS 1500$/MT, HIPS 800$/MT• : ABS 3.5t, HIPS 4-5t•• ABS HIPS
• Sheet down•• ???
Kingdom of rheology14th ICR, Aug.22-27, Seoul
• Computational rheology• Flow instability• Foams, emulsions & surfactants• Foods & biomaterials• Materials processing• Microstructural modeling• Nanorheology & microfluidics• Non-Newtonian fluid mechanics• Polymer melts• Polymer solutions• Rheometry & experimental methods• Solids & composites• Suspensions & colloids
Challenges
• Biorheology– Hemorheology, microfluidics
• IT rheology– ACF rheology, coating
• Nanorheology– Clay, CNT
• Modeling and simulation
BiorheologyCause of death(USA)
American Heart Association 2003
Cardiovascular Disease 49.9%
Cancer 32.4%
Accidents 7.1% Etc. 10.4%
Extra-corporeal life supporter
RBC deformation and hemolysis
Diabetes Association
• Most diabetics have hyperviscosity by one or other mechanism. (Dintenfass L, 1989)
• The Complication of diabetics ( Diabetic Retinopathy, Nephropathy, Nervous Diease )
Heathy retinal capillariesHeathy retinal capillaries
Diabetic retinal capillariesDiabetic retinal capillaries
Diabetic RetinopathyDiabetic Retinopathy
Introduction – RBC
In pure shear flow
Result
EI = 0.024979 EI = 0.03977 EI = 0.2453 EI = 0.348132
aspect ratio = 1.05major axis = 107.9minor axis =102.7
aspect ratio = 1.12major axis = 97.9minor axis = 87.7
aspect ratio = 1.65major axis = 120.8minor axis = 73.2
aspect ratio = 2.0681073 major axis = 134.48761 minor axis = 65.029320
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0 200 400 600 800 1000 1200
Shear rate
Elongational Index
EI = 0.392697 EI = 0.414989
aspect ratio = 2.29major axis = 140.1minor axis = 61.1
aspect ratio = 2.42major axis = 145.2minor axis = 60.0
BLOOD VISCOSITY
plasmaviscosityplasma
viscosityerythrocyte
deformabilityerythrocyte
deformability leukocyteshematocriterythrocyteaggregationerythrocyteaggregation
Early diagnosis of heart disease
Normal & Patients
ASI20 30 40 50 60 70 80 90
Avg
EI 0
.3
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40NormalPatient
ASI 20 40 60 80 100 120
Avg
EI 3
00.380.400.420.440.460.480.500.520.54
NormalPatient
Shear rate= 0.3 Shear rate= 30
stress (Pa)0.1 1 10 100 1000
EI
0.0
0.2
0.4
0.6
0.8 pure shear flow - newly testedcenterline of 4:1 contraction
Glass size vs. Coating MethodIT rheology
SpinSlit/Spin
Slit
D layer (B)D layer (top) P layerT electode B electrode SealGlass In
Washing
Coat
Dry
Washing MgO Depo.Coat
Expose
Develop
Sputtering DispenseGlass In
Upper layer
Repair
Insp CoatDry DryCleaning PR Coating
Dry FireExpose
Develop
Etch/Strip
Fire Fire
Fire
P layerGlass In RibD electrode D layerU layer
Fire
Dry
Coat
Cleaning Dry(R)
Expose
Develop
Expose
Coat(G)
Dry(G)
Develop
Coat(R)
Coat(B)
Expose
Develop
Fire
Dry(B)
Dry
Coat
Expose
Develop
Repair
Insp
Fire
Coat Coat
Dry
Glass In
Lower layer
Dry
DFR Lami.Fire
Expose
Strip
Develop
Sandblast
Fire
• 3-dimensional• Time dependent• Squeezing flow
(pseudo steady state)• Non-isothermal
(temp distribution withtime and position)
• Curing reaction• Particulate flow• Complex flow field
and geometry
particle and stress distributionstypical rheology problem
PP/clay
Electric field
Exfoliation
+II
MRC 2003
Nanorheology
Why? What happens?
•PP/Clay E2•PP/Clay
Optics measured at 180C. (x 100)
layer-stacking destructionseparation of silicate layers
(2D)⏐ 27Apr2003⏐G-NewtonFluidSimulationattime .00
0 1 2 3 4X
-3
-2
-1
0
1
Y
(2D)⏐ 27Apr2003⏐G-NewtonFluidSimulationattime .00 (2D)⏐ 27Apr2003⏐G-NewtonFluidSimulationattime .00
0 1 2 3 4X
-3
-2
-1
0
1
Y
(2D)⏐ 27Apr2003⏐G-NewtonFluidSimulationattime .00 (2D)⏐ 27Apr2003⏐G-NewtonFluidSimulationattime .00
0 1 2 3 4X
-3
-2
-1
0
1
Y
(2D)⏐ 27Apr2003⏐G-NewtonFluidSimulationattime .00 (2D)⏐ 27Apr2003⏐G-NewtonFluidSimulationattime .00
0 1 2 3 4X
-3
-2
-1
0
1
Y
(2D)⏐ 27Apr2003⏐G-NewtonFluidSimulationattime .00
Simulation & modeling
Flow past a confined cylinder
We
0.1 0.3 0.5 0.7 0.9 1.10.0 0.2 0.4 0.6 0.8 1.0 1.2
Dim
ensi
onle
ss D
rag
116
118
120
122
124
126
128
130
132
134Liu et al. (1998) : DEVSS-G/SUPGFan et al. (1999) : h-p FEMAlves et al. (2001) : FVMCaola et al. (2001) : RK4+DEVSS-G/DGOwens and Chauviere (2002) : Sprectral MethodUM2UM4
chain
dumbbell
Modeling: BD, DPD, FPD, LB,…
( )2
, , , ,
Re (1 )
0
pp
p
f
u u u p ut
u
τ λ β η
β
τ
τ
=
∂⎛ ⎞+ ⋅∇ = −∇ +∇⋅ + − ∇⎜ ⎟∂⎝ ⎠∇ ⋅ =
u
Critical to precise process control- precision injection, coating, micro-channel flow …
• Separation of long DNA molecules in a microfabricated entropic trap array, Science, 2000.