modelling tools (wp 5) - transfeu
TRANSCRIPT
Modelling tools
(WP 5)
> Final Conference
Brussels, September 25, 2012Coordinator : A. Sainrat (LNE)
Speaker : E. Guillaume (LNE)
Objectives of WP5 – Modelling tools
2
●Development of numerical simulation tools for
fire performance and evacuation of people
adapted to train scenarios in order to be used in
the FSE methodology developed in WP4
●Development of decision tool for the train
conception
Way to achieve this goal
3
●Selection of existing tools
●Development of methods to use them in various
levels of refinement
●Validation in a railway context
Structure of the work
4
Task 5.1
Simulation of fire growth
Task 5.2
Simulation of impact on people
Task 5.3
Application to coaches,
validation with WP6
Sensitivity studies
Task 5.4
Simulation of evacuation
Task 5.5
Fire barriers (relative place of safety)
Task 5.6
Simplified tools
Tools selected
5
● Risk analysis● Analytical models, Monte-Carlo coupled (WP4)
● Fire growth, heat and toxic species dispersion:● FDS-Fire Dynamics Simulator (NIST+VTT), version 5.5
● CFD-based approach, coupled with combustion modelling and heat transfers
● Evacuation● FDS-Evac (VTT) – Agent model
● Fire barriers● FDS (for thermal assessment)
● Coupling with classical FEM tools for sturctural integrity (perspective)
Fire development modelling
and
Tenability assessment
(Tasks 5.1 to 5.3)
Fire development modelling – Source term
● 3 different ways to consider fire growth
(with increasing refinement)
● Method 1: No flame spread, fire size is prescribed initially,
● Method 2: Fire spread is based on ignition criteria such as ignition
temperature
● Method 3: Fire spread is calculated according to a multi-steps
pyrolysis model
Fire development modelling - Impact
● Assessment of tenability (ASET)
● Use of a “mixture-fraction” -based approach for energy, movement
and global mass in CFD
● Use of multiple transport equations (passive scalars) to track gases
from various origins
● Tenability (heat and toxicity) assessment according to ISO 13571 ed2
(2012)
Choice of a multi-scale experimental-numerical
combined approach
Multi Scale
Multi Scale--TestsTests
SP, Sweden
TGA/DSC
LSFire,
Italy
LNE, FranceLNE, France
SP, Sweden
RATP,
France
LSFire,
Italy
Smoke Box
ISO 5659-2
Cone
Calo rimeter
ISO 5660-1
MBI ISO
21367
FTIR
Product scale ISO
24473
Compartment
scale
Real scale
1
2 3
4 5
6
Multi Scale
Multi Scale--TestsTests
SP, Sweden
TGA/DSC
LSFire,
Italy
LNE, FranceLNE, France
SP, Sweden
RATP,
France
LSFire,
Italy
Smoke Box
ISO 5659-2
Cone
Calo rimeter
ISO 5660-1
MBI ISO
21367
FTIR
Product scale ISO
24473
Compartment
scale
Real scale
1
2 3
4 5
6
Choice of a multi-scale experimental-numerical
combined approach
Multi Scale
Multi Scale -- Modelisations
Modelisations/Simulations
/Simulations
TGA
Cone Calorimeter
MBI
Product scale
Compartment scale
Real scale
1
2
3
4
5
6
Multi Scale
Multi Scale -- Modelisations
Modelisations/Simulations
/Simulations
TGA
Cone Calorimeter
MBI
Product scale
Compartment scale
Real scale
1
2
3
4
5
6
Example of detailed
methodology
Case of “Method 3”:
pyrolysis modelling
Method 1: Full scale test on seats
Full scale test (burner propane) of F1A1-2
0
50
100
150
200
250
300
0 200 400 600 800 1000 1200 1400 1600 1800 2000
TIME
HR
R (
kW
) test1
test2
fds-35
Assumptions:● Prescribed HRR from CC tests (35 kW/m2)● Burnt area (cushion and ¾ backrest of the seat) ● Ignition time: 560 s
Method 3: Wall fire propagation modeling example
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 200 400 600 800 1000 1200 1400 1600 1800
time
HR
R (
kW
)
test1
test2
fds simulation
Validation by comparison with real-scale fire tests –
Example of scenario 1A
0.00E+00
1.00E+03
2.00E+03
3.00E+03
4.00E+03
5.00E+03
6.00E+03
7.00E+03
8.00E+03
9.00E+03
0.00E+00 2.00E+02 4.00E+02 6.00E+02 8.00E+02 1.00E+03 1.20E+03 1.40E+03
time (s)
CO
2 (
pp
m)
CO2-1.7
FT1-1.7m
CO2 from various sources, comparison between exp. and
calc. At 1.7 m from floor level, in corridor, 2 m from the fire
Application to real-scale fire scenarios – 2A
Application to real-scale fire scenarios – 2A
Application to real-scale fire scenarios – 2A
● Example of results for toxicity for a single position
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
FED-propane-Toxic
FED-material-Toxic
FED-Scenario-Toxic
FED-Scenario-Heat
FEC-Material
t0: Burner
Ignition
tp: Open
the doors
tb: Stop burner
Ignition
Evacuation
and
Determination of RSET
(Required safe egress time)
(Task 5.4)
Evacuation simulations for passenger train scenarios
● A methodology for evaluating the escape safety of passenger trains in
case of fire has been created.
● Simulation tool for prediction of RSET: FDS+Evac● Simultaneous simulation of fire and evacuation
● Effects of fire on evacuation can be taken into account
● Use of same geometries in both simulations
● The evacuation simulation procedure is applicable to train scenarios with
different features and details:● Train geometries, exit door widths, exit step heights
● Dimensions and walking speeds of passenger types, luggage carrying
● Further information from VTT: [email protected]
21
Evacuation modelling of trains
Evacuation modelling of trains
Evacuation modelling of trains
● Example of expression of results
(Scenario 2B, evacuation at the platform)
Fire barriers
(Task 5.5)
Fire barriers assessment
● Tests and research performed in co-development with
ISO 834-12 and ISO 30021 standards
● First tests and modelling performed on ISO 5660 cone
calorimeter test
● Panels tested according to:● ISO 834-1 Standard curve
● EN 1363-2 Slow-heating curve
● Thermal modelling validated according to experimental tests
Experimental approach – some examples
Birch plywood core with a HPL coating, 18-20 mm thick.
EN 1363-2 Slow heating curve, integrity failure after 43 min
Aluminium and Birch plywood sandwich around a cork
rubber core, 14-15 mm thick.
ISO 834-1 standard heating curve, integrity failure after 21 min
Numerical approach – FDS validation examples
Conclusions and perspectives
Fire modelling
● Methods 1 and 2 are applicable for industrial purpose, but
very sensitive to initial hypotheses.
● Method 3 promising as perspective, but very long. This
method could be used for expertise purposes.
● Toxicity and heat tenability assessment are possible
according to ISO 13571.
● Visibility assessment is too premature, limited by modelling
tools.
30
● Method is efficient, it could be used to refine
evacuation times.
● Method used as Monte-Carlo, a large number of runs
including various people behaviour is needed for a good
assessment.
31
Methods for barriers
● Simplified assessment of integrity and insulation could be
performed with cone calorimeter.
● Reduced-scale furnace test is adapted.
● Results are conform between tests and model
Methods for evacuation
Thank youThank you