Towards a thermal characterization of a firefighter's protective clothing

Abstract

In the present work, an unsteady analysis is carried out for the thermal characterisation of a firefighter protective clothing. Coupled radiative and conduction heat transfers are considered inside the clothing with a focus on the thermal level on the first skin layer. The protective garment is modelled as a 1D solid medium, featuring three layers of tissues, separated by several air-gaps. A parametric analysis is performed in the aim to predict the effect of conductive and radiative tissue's properties fluctuation on the first skin's layer temperature. The thermal balance equations are written in a finite element (FE) formulation and solved using the COMSOL Multiphysics® software. Predictions were provided for the temperature and heat flux distributions in the fabric, skin, and air-gap as a function of time, as well as the time to receive skin burn injuries. The results obtained were compared with stationary 2-D calculations, and faced to unsteady simulations, based on the finite volume method. A 50% relative reduction in the absorptivity of the skin (in the case of wearing a fine knitted fabric) makes it possible to reduce the surface temperature of the skin to a tolerable value.