SC-GS/PI Fabio Corsanego SC-GS/PI CERN - European Organization for Nuclear Research 1 Computer Fluid Dynamic Simulation of Fire and Evacuation Scenarios for Large Experiments of Physics 5 th HEP Technical Safety Forum at SLAC Apr 2005

SC-GS/PI CERN - European Organization for Nuclear Research2 Topics Introduction CFD Codes Validation Applications Evacuation Codes Validation Applications

SC-GS/PI CERN - European Organization for Nuclear Research3 How to assess fires..let’s begin with the answer which we need; we want to know:… –…For structural integrity Long term wall temperatures Hot gases temperatures –…For life protection Early stage visibility Smoke dilution & composition Gas temperatures (Radiant heat) Mixture fraction Iso-surface plot Gas Temperature slice plot Gas Velocity vector plot Walls and objects Surface Temperature plot

SC-GS/PI CERN - European Organization for Nuclear Research4 The idea is : –To run fully instrumented small scale real fire tests (record fire power, T, p, soot, chemical species and concentration) –to obtain results by interpolation of the real fire tests by means of semi-empirical equation Bigger precision and extrapolation of the small scale tests are possible, to a certain extent (*), with Computational Flow Dynamic (CFD) How to assess fires (continued) …a glance at the CFD method… (*) CFD growing precision and validation means chance to downsize real test on materials and money saved!

SC-GS/PI CERN - European Organization for Nuclear Research5 FDS – (National Institute of Science and Technology –MD-US) (free) Phoenics (Concentr. Heat and Momentum Ldt, GB) ( eu) Fluent (Fluent Inc. GB) (price requested) Flow3d (Flow Science Inc. NM-US) Smartfire (University of Greenwich)(2500eu edu) Jasmine (Ies Limited GB) (12000eu ) Sofie (University of Cranfield – GB)(150eu) CFX Here are reported the most referenced &used CFD codes for Smoke transport-diffusion modeling Dedicated Gen.Purpose Market Survey CFD Codes (most referenced)

SC-GS/PI CERN - European Organization for Nuclear Research6 Heiss Dampf Nuclear Reactor at Karlsrhue –~50, fully instrumented oil, propane, cables fire tests in the dismantled reactor vessel (20m large, 50 m high) –FDS2 was back-validated against these data at Maryland University Memorial Tunnel Fire Test in US –~100 fully instrumented oil fire and ventilation tests –FDS2 was back-validated against these data at CERN Validation Validation effort at CERN and elsewhere on FDS2 Large scale test, well representative of large experiment halls Long tunnel test, well representative of Accelerator Tunnels

SC-GS/PI CERN - European Organization for Nuclear Research7 FDS2 Validation Heiss-Dampf Reaktor Karlsruhe Gasoil 2-4 MW fire (Test T52) Propane 1 MW fire (Test T51)

SC-GS/PI CERN - European Organization for Nuclear Research8 HDR Propane TEST T51 Data comparison FIRE room ceiling level layer Doorway ceiling level layer FIRE room floor level layer ~5% ~11% ~100% ~15% Doorway temperature profile

SC-GS/PI CERN - European Organization for Nuclear Research9 HDR TEST T52 OIL 2 MW Data comparison Doorway velocity Doorway temperature Fire room temperature ~12% ~27% ~14% ~45% O 2 ~ 8% Upper Hatch temperature More on the geometry

SC-GS/PI CERN - European Organization for Nuclear Research10 FDS2 MEMORIAL TUNNEL FIRE TEST VALIDATION The Memorial tunnel test program has provided a huge amount of raw data on road tunnel fire 8m high 8m large 850m long Flight view inside tunnel Tests

SC-GS/PI CERN - European Organization for Nuclear Research11 CASE T501: 20 MW Natural Ventilation – (Temperature) 16’ from ignition TEMPERATURES ~ F = C OBSERVED : FDS2 RESULT ~ F = C

SC-GS/PI CERN - European Organization for Nuclear Research12 Validation Overall Judgment different situations The average results of the FDS2 in different situations(*) is as follows : –Long term quasi steady Gas temperatures 20-30% of the  Terrors of the order of 20-30% of the  T –Gas Concentration errors, of ~ 1 order of magnitudelarge errors, of ~ 1 order of magnitude –Velocity of transients, like smoke layers descent and movement errors of the order of %.errors of the order of %. different situations (*) different situations: small room-small fire, small room-big fire, high bay-small fire, high bay-big fire, tunnel fire, pre-flashover, post-flashover, poor ventilation, rich ventilation, etc……!!!!!!

SC-GS/PI CERN - European Organization for Nuclear Research13 Evacuation Simulation M. Survey Evacuation simulation codes: Simulex (I.E.S. International) –License 2500€/yr Exodus 3D Greenwich University (Fire Safety Group) –License 5000 €/yr

SC-GS/PI CERN - European Organization for Nuclear Research14 What we have to assess on fires : (continued) ‘…The construction works must be designed and built in such a way that in the event of an outbreak of fire:.. –…(d) occupants can leave the construction works or be rescued –…(e) the safety of rescue teams is taken into consideration Ship muster point video Will occupants leave the structure before the smoke/fire produces untenable conditions?

SC-GS/PI CERN - European Organization for Nuclear Research15 Exodus Validation References The Validation of Evacuation Models. Authors: E Galea. CMS Press, Paper No. 97/IM/22, ISBN , 1997 The EXODUS Evacuation Model Applied to Building Evacuation Scenarios. Authors: M Owen, E Galea, P Lawrence. Journal of Fire Protection Engineering 1996, Vol.8(2), pp The Collection and Analysis of Pre-Evacuation Times from Evacuation Trials and their Application to Evacuation Modelling”. Gwynne S, Galea E.R., Parke J, Hickson J. Fire Technology, Kluwer Associates, US, pp , vol 39, number 2, 2003.

SC-GS/PI CERN - European Organization for Nuclear Research16 APPLICATIONS AT CERN

SC-GS/PI CERN - European Organization for Nuclear Research17 The fire Parabolic ramping fire power 0 -> 5MW then steadyParabolic ramping fire power 0 -> 5MW then steady Two different growth rates ( 5 MW in 700s, 1500s)Two different growth rates ( 5 MW in 700s, 1500s) Located in 3 different position (bottom, top, side)Located in 3 different position (bottom, top, side) 6 different runs per each experimental cavern6 different runs per each experimental cavern

SC-GS/PI CERN - European Organization for Nuclear Research18 ATLAS

SC-GS/PI CERN - European Organization for Nuclear Research19 Atlas Fires Locations Under Detector Top of Detector In front of one exit

SC-GS/PI CERN - European Organization for Nuclear Research20 ATLAS Videos ATLAS THE CONSTRUCTION OF THE MODEL2.avi ATLASLARGE.avi

SC-GS/PI CERN - European Organization for Nuclear Research21 ATLAS Slices (Fire under det. 5Mw 300s) t=100 s t=150 s Smoke fills upper level t=200 s Smoke starts to descend on upper gangways t= s Smoke at level of upper exits

SC-GS/PI CERN - European Organization for Nuclear Research22 CMS

SC-GS/PI CERN - European Organization for Nuclear Research23 Smoke development and transport within the cavern CMS model showcase CMS Fire Under Detector 5 MW

SC-GS/PI CERN - European Organization for Nuclear Research24 Smoke layer position on the xz plane of the cavern t=3’ t=6’t=7’ t=5’ 3 rd level gangway flooded by smoke 2 rd level gangway flooded by smoke 1 st level gangway flooded by smoke

SC-GS/PI CERN - European Organization for Nuclear Research25 Evacuation modelling 130 people in ATLAS Snapshot of the Atlas Evacuation Simulation Snapshots of the CMS Model 100 people in CMS

SC-GS/PI CERN - European Organization for Nuclear Research26 Results Overview ATLAS ATLAS: Smoke propagation to exit level gangways: 300s (medium propagation) to 480s (moderate propagation) Evacuation Time: [120s for discovery] + 90to160s= 210s to 280s Evacuation Validated

SC-GS/PI CERN - European Organization for Nuclear Research27 Results Overview CMS ATLAS: Smoke propagation to exit level gangways: 250s (medium propagation) to 360s (moderate propagation) Evacuation Time: [120s for discovery] +85 to 110s= 205 to 230s Evacuation Validated

SC-GS/PI CERN - European Organization for Nuclear Research28 Conclusions CFD and evacuation simulation tools allowed simulation and reasoned validation of complex and non standard geometries The findings show that the gap between evacuation and smoke propagation is not high Several measures have to be in place in order to minimize delays and difficulties in case of emergency …(but this is by itself a different and huge subject)