2007, Piran, Slovenia

Manikins
A NOVEL APPROACH TO MODEL-BASED EVALUATION OF
FLAME PROTECTIVE CLOTHING
Matej Gasperin 1 , Dani Juricic 1 , Bojan Musizza 1 , Miro Vrhovec 1 , Borut Lenart 1 ,
James R. House 2 & Igor B. Mekjavic 1
1 Jozef Stefan Institute, Ljubljana, Slovenia
2 Environmental Medicine Unit, Institute of Naval Medicine, Gosport, Untied Kingdom
Contact person: igor.mekjavic@ijs.si
INTRODUCTION
A new computation approach is proposed to reduce the complexity of the derivation of heat
flux values based on the temporal profile of the measured flame manikin skin temperature,
required to determine the heat conduction across the skin and the consequent burn injury
during exposure to a simulated flash fire.
METHODS AND RESULTS
Heat flux is calculated using a simple, yet comprehensive thermal model of the temperature
sensor. The computational procedure is formulated as an impulse response of the transfer
function between the measured temperature and the heat flux. This approach offers a good
quality of heat flux reconstruction, since it is based on the detailed thermal model of the
temperature sensor. It is also independent of the sensor type. A similar approach is used in the
calculation of the temperatures inside the skin. The partial differential equation describing the
heat transfer through the skin is solved numerically, resulting in the impulse responses of the
transfer functions relating heat flux to skin temperatures. The main advantage of this approach
is that the system impulse response needs to be calculated only once. During the simulation of
a flash fire, all that needs to be calculated is the heat flux by means of the simple convolution
sum between the measured temperature and the system impulse response.
DISCUSSION
The developed flame manikin system assesses the regional level of burn injury on the flame
manikin during exposure to a simulated flash fire inducing an average heat flux of 80kW.m -2
on the surface of the manikin. The protection offered by fire protective garments are tested
during exposure of the suited manikin to flash fires lasting up to 20 seconds. The system
performs acquisition of the temperature measurements from the instrumented manikin,
calculates the temperatures within the simulated skin layers and determines the level of burn
injury based on Henriques’s burn integral.
ACKNOWLEDGEMENTS
This work was supported by a Knowledge for Security and Peace grant, administered jointly
by the Ministries of Defence, and of Science (Republic of Slovenia).
REFERENCES
Henriques F.C. (1947). Studies on thermal injuries: The predictability and the significance of
thermally induced rate process leading to irreversible epidermal injury. Arch. Pathol. 43:
489.
441