Computer Fluid Dynamic Simulation of Fire and Evacuation Scenarios for Large Experiments of Physics

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Computer Fluid Dynamic Simulation of Fire and
Evacuation Scenarios for Large Experiments of
Physics

• 5th HEP Technical Safety Forum at SLAC
• 11-15 Apr 2005

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Topics

• Introduction
• CFD Codes
• Validation
• Applications
• Evacuation Codes
• Validation
• Applications

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How to assess fires ..lets begin with the
answer which we need we want to know
Walls and objects Surface Temperature plot

• For structural integrity
• Long term wall temperatures
• Hot gases temperatures
• For life protection
• Early stage visibility
• Smoke dilution composition
• Gas temperatures
• (Radiant heat)

Gas Temperature slice plot
Mixture fraction Iso-surface plot
Gas Velocity vector plot
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How to assess fires (continued) a glance at
the CFD method

• 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)

() CFD growing precision and validation means
chance to downsize real test on materials and
money saved!
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Market Survey CFD Codes (most referenced)
Here are reported the most referenced used CFD
codes for Smoke transport-diffusion modeling
Gen.Purpose
Dedicated

• FDS (National Institute of Science and
  Technology MD-US) (free)
• Phoenics (Concentr. Heat and Momentum Ldt, GB)
  (100-2000eu)
• 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

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ValidationValidation effort at CERN and
elsewhere on FDS2

• Memorial Tunnel Fire Test in US
• 100 fully instrumented oil fire and ventilation
  tests
• FDS2 was back-validated against these data at
  CERN

• 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

Large scale test, well representative of large
experiment halls
Long tunnel test, well representative of
Accelerator Tunnels
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FDS2 Validation

• Heiss-Dampf Reaktor Karlsruhe

Gasoil 2-4 MW fire (Test T52)
Propane 1 MW fire (Test T51)
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HDR Propane TEST T51 Data comparison
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FIRE room ceiling level layer
Doorway ceiling level layer
Doorway temperature profile
FIRE room floor level layer
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100
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HDR TEST T52 OIL 2 MW Data comparison
Fire room temperature
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More on the geometry
O2 8
Upper Hatch temperature
Doorway temperature
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Doorway velocity
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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
Flight view inside tunnel Tests
850m long
8m large
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CASE T501 20 MW Natural Ventilation
(Temperature)
16 from ignition TEMPERATURES
OBSERVED
150-300F 80-150C
150-300F 80-150C
FDS2 RESULT
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Validation Overall Judgment

• The average results of the FDS2 in different
  situations() is as follows
• Long term quasi steady Gas temperatures
• errors of the order of 20-30 of the DT
• Gas Concentration
• large errors, of 1 order of magnitude
• Velocity of transients, like smoke layers descent
  and movement
• errors of the order of 40-60 .

• ()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!!!!!!

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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

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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?
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Exodus Validation References

• The Validation of Evacuation Models. Authors E
  Galea. CMS Press, Paper No. 97/IM/22, ISBN 1
  899991 22 0, 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 65-86
• 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, pp173-195, vol 39, number
  2, 2003.

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APPLICATIONS AT CERN
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The fire

• Parabolic ramping fire power 0 -gt 5MW then
  steady
• Two different growth rates ( 5 MW in 700s ,
  1500s)
• Located in 3 different position (bottom, top,
  side)
• 6 different runs per each experimental cavern

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ATLAS
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Atlas Fires Locations
In front of one exit
Under Detector
Top of Detector
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ATLAS Videos

• ATLAS THE CONSTRUCTION OF THE MODEL2.avi
• ATLASLARGE.avi

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ATLAS Slices (Fire under det. 5Mw 300s)
t150 s Smoke fills upper level
t100 s
t200 s Smoke starts to descend on upper gangways
t250-300s Smoke at level of upper exits
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CMS
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Smoke development and transport within the cavern
CMS model showcase CMS Fire Under Detector 5 MW
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Smoke layer position on the xz plane of the cavern
3rd level gangway flooded by smoke
t3
t5
1st level gangway flooded by smoke
2rd level gangway flooded by smoke
t6
t7
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Evacuation modelling
100 people in CMS

• 130 people in ATLAS

Snapshots of the CMS Model
Snapshot of the Atlas Evacuation Simulation
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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

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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

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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)