Effects of layering sequence on thermal response of multilayer fibrous materials: Unsteady-state cases

Abstract: Heat transfer between multilayer fibrous materials under unsteady-state conditions is regarded as an intricate and unpredictable process, and the system thermal response with different layer stacking sequences is investigated in this paper. All six possible sequences for three-layer fabrics are measured by an apparatus set up in our lab and simulated by the finite element method, taking account of the effects caused by the internal natural convection and boundary heat loss. It is found that the fabric contacting the hot heat source is the key layer in affecting the system thermal response during the dynamic unsteady-state conditions, and its volumetric heat capacity is the major factor in determining the results. In addition, the effect of the inner natural convection in the multilayer system resulted from the buoyancy is marginal, and negligible under common boundary conditions. In general this study demonstrates that the layer stacking sequences should be considered as an important factor in thermal response while designing a multilayer thermal protective suit. [Copyright &y& Elsevier]