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 – September, 2002 – Moscow

INDEX MOTIVATIONS MEMORIAL TUNNEL DESCRIPTION FLOW MODELS NUMERICAL DETAILS NUMERICAL CAMPAIGN International PHOENICS User Conference – 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 – 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 m 2, SLOPE: 3.2 % –JET FAN: air velocity: 34.2 m/s, mass flow rate: 43 m 3 /s International PHOENICS User Conference – September, 2002 – Moscow

MEMORIAL TUNNEL 2/5 SECTIONS y z NORTH ROOM 21.3m sect. A sect. B sect. A sect. B 0.76 m 4.33 m 8.76 m 0.91 m Sect. B 7.86 m 8.76 m 0.91 m Sect. A Walkway y x 853,7 m 811 m 4.33 m 7.86m SOUTH ROOM International PHOENICS User Conference – September, 2002 – Moscow

MEMORIAL TUNNEL 3/5 PLANT m ON m NorthNorth SouthSouth Pan 615 x z Jet Fans Flow Slope 3,2 % International PHOENICS User Conference – September, 2002 – Moscow OUTLETOUTLET INLETINLET

MEMORIAL TUNNEL 4/4 PANS International PHOENICS User Conference – September, 2002 – Moscow

MEMORIAL TUNNEL 5/5 JET FANS International PHOENICS User Conference – 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 – September, 2002 – Moscow

NUMERICS 1/2 COMPUTATIONAL GRID: 31 X 30 X 327 cells 2.44 m R = 4.33 m m 3.48 m R = 2.1 m 8.76 m Walkway y x International PHOENICS User Conference – 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 – 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 – 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 TEST VENTILA TION JET FANS M. FLOW Kg/s ERROR ExpLongitud T-ALongitud % International PHOENICS User Conference – 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 – September, 2002 – Moscow

NUMERICAL CAMPAIGN 3/10 FIRE SIMULATION CRITICAL VELOCITY: 1.8 m/s (104 m 3 /s) COMPARISONS TEST Total Heat Rate (MW) Jet Fan Ventila tion Radiat. Model Mass Flow Rate (kg/s) Error % Exp9.102Long T-B6.362Long.No T-C9.102Long.Yes International PHOENICS User Conference – September, 2002 – Moscow

NUMERICAL CAMPAIGN 4/10 FIRE SIMULATION COMPARISONS ( V and T PROFILES) –MEASUREMENT POSITIONS LOOP NAME DISTANCE from NORTH PORTAL L m L m L m L m L m International PHOENICS User Conference – September, 2002 – Moscow

NUMERICAL CAMPAIGN 5/10 FIRE SIMULATION COMPARISONS ( T and V PROFILES) L214 (18 m) Pan International PHOENICS User Conference – 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 – September, 2002 – Moscow

NUMERICAL CAMPAIGN 7/10 FIRE SIMULATION COMPARISONS ( T and V PROFILES) L305 (604 m) Pan International PHOENICS User Conference – 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 – 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 – September, 2002 – Moscow

NUMERICAL CAMPAIGN 10/10 FIRE SIMULATION T contours International PHOENICS User Conference – 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 International PHOENICS User Conference – September, 2002 – Moscow

S. GOTTARDO – 17 Km Switzerland International PHOENICS User Conference – September, 2002 – Moscow