Afterburner microscopic analysis of the nozzle insert material of the solid propellant rocket engine:

theoretical conception (Part I)

Abstract

This work presents a study conducted in the Materials Division (AMR), subordinated to the Institute of Aeronautics and Space (Instituto de Aeronáutica e Espaço - IAE), organization of the Department of Aerospace Science and Technology (DCTA), to investigate the microstructural behavior of carbon/ carbon composite based material used as heat shield/insert in nozzle throat of rockets. These systems are subjected to an intense heat flow from the gases at high speed, which lead to the ablation phenomenon in the nozzle regions in solid propulsion engines of S43 vehicles, for example. Ablation is an erosive phenomenon that occurs in regions of the thermal protection system and whose material is removed by thermomechanical, thermochemical and thermophysical or combined influences. Thus, in order to maintain the integrity of the nozzle, materials such as Thermal Protection Systems (TPS) are used. The materials for thermal protection can be classified, according to the predominant mechanism of protection, in ablatives and reirradiant. Most of the ablative materials are composites reinforced with structural fibers (silica or carbon, for example) and bonded with organic thermo rigid resins and the class of reirradiant materials include carbon mesh thermostructural composites reinforced with carbon fibers (CRFC), composites with silicon carbon/silicon carbide (C/SiC) hybrid mesh, and the silicon carbide mesh and fibers composites (SiC/SiC) and covalent ceramic materials such as ZrC, HfC and TaC, for example, mainly in the form of internal modifying materials or as coatings.