Competitive kinetic model for the pyrolysis of the Phenolic Impregnated Carbon Ablator

Abstract

Carbon/phenolic ablators are successfully used as thermal protection material for spacecraft. Nevertheless, their complex thermal degradation is not yet fully understood, and current pyrolysis models do not reproduce important features of available experimental results. Accurate and robust thermal

Decomposition of carbon/phenolic composites for aerospace heatshields: Detailed speciation of phenolic resin pyrolysis products

“…Firstly, it provides the level of confidence of the experimenter about the data, which can be assessed by performing several repetitions of the same conditions. Secondly, it is important for readers who are interested in developing computer models using the experimental data, for which the uncertainty in the measurements will play a significant role on the results [8].…”

“…It seems that char production is related to the heating rate, as it is also in the pyrolysis of biomass [41][42][43][44][45]. At slow heating rates (traditional TGA), certain competitive reactions [8] in the pyrolysis of phenolic may produce char/residue already at low temperatures, and only when temperature is higher, the more relevant mass loss occurs. Thus, the shift towards lower temperatures that can be observed in the graph.…”

“…This effect may be of great importance for the development of TPM for spacecraft since current models do not take a variable char yield into account, with the exception of competitive schemes [8]. In TPM, one may expect heating rates ranging from thousands of degrees per second for the part of the material facing the flow, to few degrees per minute for the deepest part of the heatshield [36].…”

“…While the gas phase chemistry is relatively well understood, the knowledge of the pyrolysis process and the generation of pyrolysis gases is still limited, and most models rely on lumped, Arrhenius-like reactions. Multi-component parallel reactions [5][6][7] or more recently competitive reactions [8] are generally employed to model pyrolysis.…”

Experimental measurement of thermal shock wave in C/Ph induced by electron beam radiation

“…In recent years, with the development of material science and the demand of application field, new carbon phenolic materials based on modified high performance phenolic resin have been paid more and more attention. The studies are mainly focused on the fabrication, ablation mechanism and thermodynamic parameters of the C/Ph composite [3][4][5][6][7][8][9]. The physical and mechanical properties of this new material, especially the characteristics of thermal shock wave produced by pulse radiation, is one of the hot issues that people pay close attention to.…”