1 tasks 4.1 4.2 cudam - department of civil and environmental engineering university of trento...
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1
Tasks 4.1 4.2
CUDAM - Department of Civil and Environmental EngineeringCUDAM - Department of Civil and Environmental Engineering
University of TrentoUniversity of Trento
Louvain-la-Neuve, Louvain-la-Neuve, NovNov 5 5thth-7-7thth 2003 2003IMPACT Investigation of Extreme Flood Processes & Uncertainty
Composition of the group:a.armaninic.dalrì r.fabrizim.giulianil.fraccarollom.larcherg.rosatti
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Experimental installation
Conveyer belt
High slope tilting channel
3
Flow regimes
immature mature
plug rigid bed
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0.1
1
10
100
1000
0 0.2 0.4 0.6 0.8C [-]
t s (d
rs C
T1/
2 g )
-1 [-
]
1
10
100
1000
0 0.2 0.4 0.6 0.8C [-]
s s (C
rs T
)-1 [-]
1
10
100
1000
0 0.2 0.4 0.6 0.8C [-]
s s (C
rs T
)-1 [-]
0.1
1
10
100
1000
0 0.2 0.4 0.6 0.8C [-]
t s (d
rs C
T1/
2 g )
-1 [-
]
)1(2
21
C
Cr
Collisional regime
Added mass (Lamb, 1932)
5
0.1
1
10
100
1000
10000
100000
1 10 100 1000 10000
Ba [-]
s s/[r w
2 hw
2 l/(r s
D2 )]
[-]
macroviscous
grain-inertia
Bagnold (1954)
)32.0(tancos042.0 12 Dss glrs
2/12
lh
grr
ww
s DBa
6
Mechanical energy balanceMature
-1.8
-1.6
-1.4
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
-0.5 -0.3 -0.1 0.1 0.3 0.5
energy functions [-]
z [-
]
dissipation
diffusion
production
Immature
-1.4
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
-0.05 -0.03 -0.01 0.01 0.03 0.05
energy functions [-]
z [-
]
dissipation
diffusion
production
Plug
-4.0
-3.5
-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
-0.3 -0.2 -0.1 0 0.1
energy functions [-]
z [-
]
dissipation
diffusion
production
Rigid bed
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
-0.15 -0.1 -0.05 0 0.05 0.1 0.15
energy functions [-]
z [-
]
dissipation
diffusion
production
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Bimodal material: quasi-uniform conditions and adaptation
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Erosional Dam Break
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Theoretical and physical Solutions
Erosional Dam Break
Fraccarollo L., Capart, H.,
"Riemann wave description of erosional dam-break flows",
Journal of Fluid Mechanics, 461, 183-228, 2002.
Fraccarollo L., Capart, H. and Zech, Y.,
"A Godunov method for the computation of erosional shallow water transient",
Int. Journal of Numerical Methods in Fluids, 41:951-976, 2003.
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Experimental assessment of the self-similarity
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Use of finer sediment Two-dimensional effects near to the front
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Dam-break with different initial conditions
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Gradino di valle
-0.1
-0.05
0
0.05
0.1
0.15
0.2
1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5
x (m)
z (m
)
fondo_(m)
quota tirante (m)
tirante_sperim(m)
fondo_sperim(m)
tirante iniziale
fondo iniziale
a)
Gradino di monte
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8
x (m)
z (m
)
tirante (m)
fondo (m)
tirante sperim (m)
fondo sperim (m)
tirante iniziale
fondo iniziale
a)
Comparison analytical-physical solutions
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-2.0
-1.8
-1.6
-1.4
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
u [ - ]
z [
- ]
h = 10 cm
h = 20 cm
a)
Confronto h = 10, 20 cm
-2.0
-1.8
-1.6
-1.4
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
c [ - ]
z [
- ]
h = 10 cm
h = 20 cm
b)
Confronto h = 10, 20 cm
-2.0
-1.8
-1.6
-1.4
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040
T [ - ]
z [
- ]
h = 10 cm
h = 20 cm
c)
Measurements of the variable profiles
15
Immature debris flow:Immature debris flow:
mean velocity
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
-0.5 0 0.5 1 1.5 2 2.5velocity [m s-1]
z [m
]
free surface
u
v
w
velocity fluctuations
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0 0.05 0.1 0.15 0.2 0.25velocity fluctuations [m s-1]
z [m
]
free surface
u'
v'
w'
Stokes number
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0 10 20 30 40 50Stokes [-]
z [m
]
free surface
critical Stokes
Stokes
concentration
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8c [-]
z [m
]
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Mass entrainment and transport phenomena
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Tasks 4.1 4.2
CUDAM - Department of Civil and Environmental EngineeringCUDAM - Department of Civil and Environmental Engineering
University of TrentoUniversity of Trento
Louvain-la-Neuve, Louvain-la-Neuve, NovNov 5 5thth-7-7thth 2003 2003IMPACT Investigation of Extreme Flood Processes & Uncertainty
Composition of the group:a.armaninic.dalrì r.fabrizim.giulianil.fraccarollom.larcherg.rosatti