EFFECTS OF BOUNDARY CONDITIONS ON MPS · Determination of calorific value” ... to achieve...

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© Diehl Aviation

EFFECTS OF BOUNDARY CONDITIONS ON MPS

TESTINGKarsten Kirbach

Research Systems2019 May 14th

2Titel der Präsentation, Abteilungskürzel, StandVertraulich C0-C3, © Diehl Stiftung & Co. KG

2Folienmaster, Communications & PR, 09/2018

© Diehl Aviation2© DIEHL AVIATION

Motivation

• For development and certification of a halon replacement fire suppression system extensive testing in alignment with the MPS is necessary.

• Reference for testing and test results is the MPS Test Article at the FAA Technical Center.

• To achieve a high comparability a replica test article needs to be as similar as possible to the FAA MPS Test Article.

• The Minimum Performance Standard for Aircraft Cargo Compartment Halon Replacement Fire Suppression Systems is giving guidelines to build a replica test article, however some boundary conditions may not be defined in sufficient detail to achieve comparability.

EFFECTS OF BOUNDARY CONDITIONS ON MPS




GUIDELINES GIVEN BY THE MPS

“The fire load […] consists of single-wall corrugated cardboard boxes, […] of 18 by 18 by 18 inches (45.7 by 45.7 by 45.7 cm). The weight per unit area of the cardboard is 0.11 lb/ft2 (0.5417 kg/m2).”

“The boxes are filled with 2.5 pounds (1.1 kg) of loosely packed standard weight office paper shredded into strips (not confetti).”




Shredded Paper

CALORIFIC VALUE OFCOMMON MPS FIRE LOADS

• Gross Calorific Value acc. DIN EN ISO 18125: 2017-08 „Solid biofuels -Determination of calorific value”

• Samples are grinded down and burnedwithin a bomb calorimeter

• Samples FAA 1 and FAA 2 provided byDhaval Dadia

• Up to 20% difference in Gross CalorificValue

75%

80%

85%

90%

95%

100%

105%

110%

115%

FAA 1 FAA 2 sample No. 1 sample No. 2 sample No. 3

Gro

ss C

alo

rifi

c V

alu

e

Shredded Paper used for MPS testing

water free

conditioned




Cardboard Boxes


• Gross Calorific Value acc. DIN EN ISO 18125: 2017-08 „Solid biofuels -Determination of calorific value”

• Samples are grinded down and burnedwithin a bomb calorimeter

• Samples FAA 1 provided by Dhaval Dadia

• Up to 16% difference in Gross CalorificValue

75%

80%

85%

90%

95%

100%

FAA 1 sample No. 1 sample No. 2

Gro

ss C

alo

rifi

c V

alu

e

Cardboard Boxes used for MPS testing

water free

conditioned




Packed MPS Boxes


• Theoretical Gross calorific Value per packed MPS Box

• Up to 13% difference in GrossCalorific Value

• Samples FAA MPS Box 1 and FAA MPS Box 2 provided by DhavalDadia

• Macroscopic combustion behavioris not considered!

75%

80%

85%

90%

95%

100%

105%

Gro

ss C

alo

rifi

c V

alu

e

packed Boxes used for MPS testing

water free

conditioned




GUIDELINES GIVEN BY THE MPS

“The fire tests are conducted inside a. The volume of the compartment is 2000 ±100 cubic feet (56.6 ±2.8 m3) (see figure 1).”




1371 kg

493 kg 477 kg

0 kg

350 kg

700 kg

1050 kg

1400 kg

1750 kg

0,0 kJ/K

150,0 kJ/K

300,0 kJ/K

450,0 kJ/K

600,0 kJ/K

750,0 kJ/K

Galvanized SteelGA16

Aluminium GA14 glassfiber reinforcedplastics

The

rmal

Ma

ss

Mass Properties of Lining Materials

Thermal Mass

Lining Net Mass

THERMAL PROPERTIES OF MPS TEST CELL LINING MATERIALS

• Lining Material for MPS Test cell isnot specified

• Up to 56% difference in thermal mass

• Thermal mass may influence MPS results

Possible effects:

Damping of peak temperatures

Increased thermal inertia of thetest setup

Dhaval Dadia, Oct 31 2018 –

Rebuild of the Cargo MPS Test Article




32,20E-06 K/W 9,87E-06 K/W000,00E+00 K/W

2,00E-03 K/W

4,00E-03 K/W

6,00E-03 K/W

8,00E-03 K/W

Galvanized Steel GA16 Aluminium GA14 glassfiber reinforcedplastics

The

rmal

Re

sist

ance

pe

r m

²

Thermal Properties of Lining Materials

THERMAL PROPERTIES OF MPS TEST CELL LINING MATERIALS

• Lining Material for MPS Test cell is not specified

• Several orders of magnitude difference in thermal conductivity and thus thermal resistance

• Thermal conductivity and resistance may influence MPS results

Possible effects:

Faster/slower heat conduction through lining material

In-/decreased convective cooling at exterior of test cell(depending on outside surface- and surrounding environmental temperatures)

Increased susceptibillity for surrounding environmental conditions (e.g. temperature, airflow, …) if test cell lining isnot enclosed or insulated

0,34 W/m*K0,00 W/m*K

50,00 W/m*K

100,00 W/m*K

150,00 W/m*K

200,00 W/m*K

Galvanized Steel GA16 Aluminium GA14 glassfiber reinforced plastics

The

rmal

Co

nd

uct

ivit

y

Thermal Properties of Lining Materials




Karsten Kirbach

Research SystemsProduct Innovation

Phone: +49 351 88597 [email protected]

• Further investigation of macroscopiccombustion behavior of common MPS fire loadsis needed to better understand possible impacton MPS test results.

• A more detail definition of „simulated, below-floor cargo compartment of a wide-body aircraft” and „loosely packed standard weight office paper shredded into strips” is necessary to achieve comparable boundary conditions for different test articles.

• Cargo compartment lining material, surrounding structural buildup, insulation materials and buildup as well as shredded paper composition may need to be specified in more detail.

SUMMARY CONTACT

mailto:[email protected]

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Diehl Aviation Holding GmbH

Vorname Nachname

Am Flugplatz88471 Laupheim

Deutschland

Tel +49 7392 703-0 Fax +49 7392 709-1860

diehl.com/aviation

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EFFECTS OF BOUNDARY CONDITIONS ON MPS · Determination of calorific value” ... to achieve...

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