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: Terhi.Kling@vtt.fi

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