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A CFD METHODOLOGY FOR FIRE SPREAD AND RADIATIVE EFFECTS SIMULATION IN LONGITUDINAL VENTILATION TUNNELS: APPLICATION TO THE MEMORIAL TUNNEL. D. Borello*, G.Giuli** and F. Rispoli* *DepartMent of Mechanics and Aeronautics University of Rome ‘La Sapienza’ - PowerPoint PPT Presentation
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A CFD METHODOLOGY FOR FIRE SPREAD
AND RADIATIVE EFFECTS SIMULATION IN
LONGITUDINAL VENTILATION TUNNELS:
APPLICATION TO THE MEMORIAL TUNNEL
D. Borello*, G.Giuli** and F. Rispoli*
*DepartMent of Mechanics and Aeronautics University of Rome ‘La Sapienza’
**ENEA – Italian Agency for the Energy, the New Technologies and the Environment
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
INDEX
• MOTIVATIONS
• MEMORIAL TUNNEL DESCRIPTION
• FLOW MODELS
• NUMERICAL DETAILS
• NUMERICAL CAMPAIGN
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
MOTIVATIONS
• MAJOR INTEREST IN TUNNEL SAFETY AND POLLUTION CONTROL
• EXPERIMENTAL RESULTS GIVE PARTIAL FLOW INFORMATION
• DEVELOPING A NUMERICAL METHODOLOGY DEVOTED TO
TUNNEL FLOW SIMULATION ABLE TO:
– PREDICT THE FLOW BEHAVIOR IN OPERATING CONDITIONS
– DESCRIBE THE FIRE SPREAD IN ORDER TO:
• PREDICT MAIN FLOW PHENOMENA
BACK-LAYERING AND SMOKE DIFFUSION
• DEFINE THE BEST VENTILATION CONFIGURATION IN
EMERGENCY SITUATIONS
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
MEMORIAL TUNNEL 1/5
Memorial Tunnel Fire Ventilation Program Massachusetts Highway Department & Bechtel/Parsons
Brinckerhoff, Massachusetts, November 1995
• EXPERIMENTAL CAMPAIGN (1995)– LONGITUDINAL, TRANSVERSAL, MIXED CONFIGURATIONS
– LONGITUDINAL CONFIGURATION :
15 JET FANS (in groups of three)
– LENGTH: 853 m, PASSAGE SECTION: 60.4 m2, SLOPE: 3.2 %
– JET FAN: air velocity: 34.2 m/s, mass flow rate: 43 m3/s
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
MEMORIAL TUNNEL 2/5
• SECTIONS
y
z
NORTHROOM
21.3m
sect. A sect. B
sect. A sect. B
0.76 m
4.33 m
8.76 m
0.91 m
Sect. B7.86m
8.76 m
0.91 m
Sect. A
Walkway
y
x
853,7 m
811 m
4.33 m
7.86m
SOUTHROOM
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
MEMORIAL TUNNEL 3/5
• PLANT
853.7 m
ON ON
474 379 285 190 950 m
N o r t h S o u t h Pan
615
x
z
14
15
13
2
3
1
8
9
7
5
6
4
11
12
10
Jet Fans Flow
Slope 3,2 %
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
OUTLET
INLET
MEMORIAL TUNNEL 4/4
• PANS
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MEMORIAL TUNNEL 5/5
• JET FANS
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
FLOW MODELS
• 3-DIMENSIONAL, STEADY, TURBULENT REACTING FLOW
• TURBULENCE MODELING– STANDARD k- MODEL (Jones and Launder, 1988)
• BUOYANCY MODELING
• COMBUSTION MODELING – HEAT SOURCE PLACED IN THE FIRE LOCATION
• RADIATION MODELING
– IMMERSOL SYNTHETIC TREATMENT (Spalding, 1991)
– NO RADIATION MODELING (Pucher et al., 2001)
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
NUMERICS 1/2
• COMPUTATIONAL GRID: 31 X 30 X 327 cells
2.44 mR = 4.33 m
1.575 m
3.48 m
R = 2.1 m
8.76 m
Walkway
yx
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
• BFC GRIDS
• GENERALISED CO-LOCATED SCHEME
• SIMPLE SOLUTION SCHEME
• FALSE TIME STEP RELAXATION FOR V and T
• WALL ROUGHNESS : 3 mm
NUMERICS 2/2
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
ANALYSED TEST CASES
• COLD FLOW TEST: (T-A)
– 15 JET FANS
• T606A FIRE TEST (10 MW): (T-B, T-C)
– 2 JET FANS
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
NUMERICAL CAMPAIGN 1/10
COLD FLOW SIMULATION
• OPERATING CONDITIONS:
– 15 ACTIVE FANS
– SWIRL NUMBER: 0.5
– CONSTANT PROPERTIES GAS
– WALL LAW FOR VELOCITY INSIDE THE TUNNEL
– FREE BOUNDARY CONDITIONS IN INLET AND OUTLET
• COMPARISONS
TESTVENTILA
TIONJET
FANSM. FLOW
Kg/sERROR
Exp Longitud. 15 498.5 -
T-A Longitud. 15 556.5 10.4 %
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
NUMERICAL CAMPAIGN 2/10
FIRE SIMULATION
• TEST CASE T606A 10 MW
• OPERATING CONDITIONS:
– 2 ACTIVE FANS
– SWIRL NUMBER: 0.5
– IDEAL GAS
– WALL LAW FOR VELOCITY AND TEMPERATURE
– FREE BOUNDARY CONDITIONS IN INLET AND OUTLET
• SYNTHETIC AND DIRECT RADIATION SIMULATION
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
NUMERICAL CAMPAIGN 3/10
FIRE SIMULATION
• CRITICAL VELOCITY: 1.8 m/s (104 m3/s)
• COMPARISONS
TESTTotal Heat
Rate
(MW)
Jet
Fan
Ventila
tionRadiat. Model
Mass Flow Rate
(kg/s)
Error
%
Exp 9.10 2 Long. - 163 -
T-B 6.36 2 Long. No 147.2 -9.8
T-C 9.10 2 Long. Yes 137.2 -15.8
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
NUMERICAL CAMPAIGN 4/10
FIRE SIMULATION
• COMPARISONS ( V and T PROFILES)
– MEASUREMENT POSITIONS
LOOP NAMEDISTANCE from NORTH PORTAL
L214 18 m
L209 321 m
L305 604 m
L302 681 m
L202 833 m
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
NUMERICAL CAMPAIGN 5/10
FIRE SIMULATION• COMPARISONS ( T and V PROFILES)
L214 (18 m) Pan
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
a) b)
V (m/s) T (°C)
Loop 214 – Temperature (a) and velocity (b) profiles
a) b)
T (°C) V (m/s)
Loop 209 – Temperature (a) and velocity (b) profiles
NUMERICAL CAMPAIGN 6/10
FIRE SIMULATION• COMPARISONS ( T and V PROFILES)
L209 (321 m) Pan
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
NUMERICAL CAMPAIGN 7/10
FIRE SIMULATION• COMPARISONS ( T and V PROFILES)
L305 (604 m) Pan
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
a) b)
T (°C) V (m/s)
Loop 305 – Temperature (a) and velocity (b) profiles
NUMERICAL CAMPAIGN 8/10
FIRE SIMULATION• COMPARISONS ( T and V PROFILES)
L302 (681 m) Pan
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
a) b)
V (m/s) T (°C)
Loop 302 – Temperature (a) and velocity (b) profiles
NUMERICAL CAMPAIGN 9/10
FIRE SIMULATION• COMPARISONS ( T and V PROFILES)
L202 (833 m) Pan
a) b)
V (m/s)
T (°C)
Loop 202 – Temperature (a) and velocity (b) profiles
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
NUMERICAL CAMPAIGN 10/10
FIRE SIMULATION
• T contours
T (°C)
3 25 47 69 91
113 135 157 179 201 223 245 267 290 312
V (m/s)
,0 ,4 ,8 1,2 1,6 2,0 2,4 2,7 3,1 3,5 3,9 4,3 4,7 5,1 5,5
TEMPERATURE
4 PANS
VECTOR
International PHOENICS User Conference – 23-27 September, 2002 – MoscowInternational PHOENICS User Conference – 23-27 September, 2002 – Moscow
CONCLUSIONS
• AN ACCURATE METHODOLOGY FOR FIRE SIMULATION IN
TUNNELS HAS BEEN DESCRIBED
• THE PREDICTION CAPABILITIES HAVE BEEN DEMONSTRATED
IN CRITICAL FLOW CONDITIONS
• SUCCESSFUL SIMULATION OF RADIATION PHENOMENA
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S. GOTTARDO – 17 Km Switzerland 24.10.2001
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