Development and characterization of a contoured passive thermal protection system

Abstract

Present work deals with process refinement, fabrication, and testing of a novel contoured passive thermal protection system (TPS), based on aluminosilicate fiber reinforced silica matrix composite. Taguchi method‐based statistical approach was employed to understand the effect of process parameters such as thickness, layer density, stacking sequence and firing temperature on dielectric properties, flexural strength, and bulk density of composites. Analysis of variance was performed to ensure the statistical significance. The developed TPS was characterized for thermal insulation properties by testing under infrared heating conditions. The science behind the insulation characteristics of the TPS was analyzed using FTIR, XRD, and SEM to understand the associated high‐temperature phase transitions. Present study has shown that, the back‐face temperature exponentially decays with TPS thickness. For TPS having 9 mm thickness, the back‐face temperature was found to be below 100°C when the front face was exposed to 1000°C. The insulation index was found to be increasing with increase in temperature and TPS thickness. Improved thermal insulation characteristics of TPS are due to energy consuming processes such as crystalline changes and micro cracks formation.

Effect of Boron Nitride Addition on Ablation Characteristics of Carbon Fiber Reinforced Resorcinol Formaldehyde Composites

“…This composite was found to have enhanced ablation resistance, interlaminar shear strength, and reduced thermal conductivity. Passive thermal protection systems based on silicon dioxide and aluminosilicate were also reported in the literature …”

“…Passive thermal protection systems based on silicon dioxide and aluminosilicate were also reported in the literature. 24 Nanosilica incorporation on the material recession behavior of chopped C-Ph composites was explored by Mirzapour et al 25 Knop et al reported that incorporation of B, P, or Si elements into the atomic structure of phenolics has enhanced the oxidation resistance. 26 The effects of ZrB 2 incorporation on thermal characteristics of C-Ph composites were studied by Chen et al 19 The ablation resistance was found to be improved with the increased ZrB 2 .…”

Zirconium-Doped Hybrid Composite Systems for Ultrahigh-Temperature Oxidation Applications: A Review

“…A value of 4 kcal represents over 16 700 J, whereas the heat insulation during re-entry would vary from 12 GJ to 340 GJ. Considering the Apollo space capsule, which had a mass of 12 200 lb, which is approximately 5500 kg and the total energy was reported to be 340 GJ (both potential and kinetic energies of 5500 kg), which is 62 kJ g –1 and, in contrast to the chemical heat of 16.7 kJ g –1 , as we previously mentioned, is ∼27% of the former energy value (62 kJ g –1 ), absorbing 27% of aerodynamic heat and conserving it in product form of a chemical reaction is quite a significant phenomenon; however, the much more modern ablative systems, which include ultrahigh temperature ceramics such as zirconium ceramics have reported that, upon the onset of oxidation of zirconium ceramics, which certainly leads to the formation of zirconia, much of the heat was consumed by zirconia for phase transformation and dilation , with the magnitude of heat sunk into the material albeit not been recorded. But few of the modern research groups (viz., Badhe et al , ) have doped resorcinol formaldehyde with carbon soot obtained from the controlled combustion of camphor, which could be a suitable matrix modifier for the requirements of moderate char yield of 59% after pyrolysis at 800 °C with an interesting ablation rates of 0.019 mm/s and 0.053 g/s, Badhe et al, had developed a novel idea by modifying resorcinol formaldehyde, a superorganic chain, with recycled waste rubber, and have reported that the degradation temperature was enhanced by 13% and mass ablation rates by 11%.…”

“…Furthermore, for the best utilization of the ablative materials, the knowledge required is not just limited to the technical know-how; in addition, the results obtained from experiments and mathematical stipulation must be optimized. One method that has developed a reliable method to optimize the composition of the composite system is the Taguchi technique and had been implemented in recent past for the optimization of passive TPS material, as reported by Daniel et al , Furthermore, the phenolic matrix, ablative, in comparison, offer less density than that of ZrC- and SiC-doped carbon–carbon composites , and it could be prudent enough to infer that for better results an ablative must have high mechanical strength, high thermal shock resistance, high ablation, and oxidation resistance. It is important to acknowledge that, for phenolic resins, as reported by Swann et al., the densities of 400–480 kg/m 3 have offered best results of ablation performance; however, the ablation performance has been reported to be an intensive property .…”