Speaker
Description
During the atmospheric entry, the decommissioned satellite is strongly affected by aerodynamic heating due to dissipation of a huge amount of kinetic energy into thermal energy. In these conditions, the vehicle usually breaks-up into several parts which are, in turn, degraded by the high enthalpy flow. However, Carbon Fiber Reinforced Polymers (CFRP) materials behave similarly to thermal protection ablators and, hence, show a strong resistance when exposed to high enthalpy flows. For instance, objects made with this type of material like Composite Overwrapped Pressure Vessels (COPV) often survive the re-entry. This component is made of a metallic liner wrapped in CFRP. During the atmospheric entry, the COPV will be exposed to a high enthalpy flow, which will progressively pyrolyze the resin of the CFRP, then erode by thermo-chemical phenomena the remaining carbonaceous residue together with the carbon fibers and finally melt the liner if the heat load is sufficient. To assess the performance of these tanks, two experimental test campaigns were conducted. One campaign investigated tank performance in a subsonic regime, while the other focused on the supersonic regime.
High-fidelity models have been developed in recent years to predict the response of light porous ablative thermal protection materials such as PICA and there is a growing interest in exploring the possible extension of those models to predict the demisability of space debris composite materials. The objective of this work was to perform an experimental and numerical campaign reproducing the demise of COPVs. Miniaturized COPV samples have been designed and manufactured to avoid delamination of the fiber layers. Those have been exposed to relevant atmospheric entry conditions in the Plasmatron facility at the von Karman Institute [1]. The subsonically tested samples were then simulated using the high-order discontinuous Galerkin code Argo. This employs a unified method, solving the surrounding flow and material response in the same domain of computation. It uses volume averaging theory to describe flow through the porous material and to capture with accuracy the gas-surface interaction. .
This methodology has shown its advantages to predict the response of low-density porous materials but its extension to very dense composite materials such as CFRP presents several numerical challenges that we will discuss. Experimental data and numerical results will be presented and compared. The interpretation of the results will aid in laying the foundation for a technological use of these procedures in the design phase of components susceptible to re-enter our atmosphere.
Reference:
1) J.ElRassi, B. Helber, P. Schrooyen, A . Turchi, P. Jorge, T. Magin, L. Walpot, Plasma testing of miniaturized composite Overwrapped pressure vessels in reentry conditions. 10th EUCASS Aerospace Europe Conference 2023. DOI:10.13009/EUCASS2023-957
