Probabilistic modeling of transient heat transfer and assessment of thermal reliability of fibrous insulation under aerodynamic heating conditions

In present paper, the probabilistic thermal analysis of the fibrous insulation subjected to aerodynamic heating conditions was performed to account for the uncertainties such as material properties, loading conditions and geometrical variations. The statistical analysis of thermal response showed that the response temperature was significantly dependent on time and location. Large variations in the statistics parameters were observed at the location where temperature slip occurred for the first one minute of entry. To identify the dominant variables which most influence temperature response scatter, the correlation coefficients of various variables were computed. The results showed that the aerodynamic heating temperature and initial temperature had significant effects for the considered locations. However, the extinction coefficient, the specific heat of virgin material and the solid fraction ratio had non-negligible effect on the back side temperature scatter of fibrous insulation. Furthermore, the relationship between the probabilistic thermal reliability and thickness factor of safety was developed. Quantitative as well as qualitative information is provided in the present methodology, which is valuable to the thermal analysis, design and testing of fibrous materials.