Ablative thermal protection system under uncertainties including pyrolysis gas composition

Abstract

Spacecrafts such as Stardust (NASA, 2006) are protected by an ablative Thermal Protection System (TPS) for their hypersonic atmospheric entry. A new generation of TPS material, called Phenolic Impregnated Carbon Ablator (PICA), has been introduced with the Stardust mission. This new generation of low density carbon-phenolic composites is now widely used in the aerospace industry. Complex heat and mass transfer phenomena coupled to phenolic pyrolysis and pyrolysis gas chemistry occur in the material during atmospheric entry. Computer programs, as the Porous material Analysis Toolbox based on OpenFoam (PATO) released open source by NASA, allow to study the material response. In this study, a non-intrusive Anchored Analysis of Variance (Anchored-ANOVA) method has been interfaced with PATO to perform low-cost sensitivity analysis on this problem featuring a large number of uncertain parameters. Then, a Polynomial-Chaos method has been employed in order to compute the statistics of some quantities of interest for the atmospheric entry of the Stardust capsule, by taking into account uncertainties on effective material properties and pyrolysis gas composition. This first study including pyrolysis gas composition uncertainties shows their key contribution to the variability of the quantities of interest.

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

“…However, it lacks in generality and fails when applied to largely different heating rates. For ablation modeling at varying heating rates this is a substantial limitation, no longer acceptable as we aim at physics-based predictions of the ablation phenomenon [14]. Indeed, a broad range of heating rates is found in ablative heat shields used in atmospheric entry.…”

Strong Effect of Process Parameters on the Properties of Boron-Containing Phenolic Resins with High Char Yield

“…The Phenolic Impregnated Carbon Ablator (PICA) developed at NASA Ames Research Center is a state-of-the-art carbon/phenolic ablator, which exhibits low mass per unit volume and superior ablation property. Research results have confirmed that PICA offers outstanding anti-ablation performance, along with a low-density property (about 0.2-0.4 g/cm 3 ) [7][8][9][10].…”

Ablation Behavior of a Carbon Fabric Reinforced Phenolic Composite Modified by Surface-Decorated ZrB2/SiC

“…The serious heating flow formed by the intense friction between a hypersonic vehicle and the surrounding air severely affects the flight stability of an aircraft [1][2][3][4]. Carbon fabric reinforced phenolic (C-Ph) composites possessing high thermal stability and good mechanical property is an ideal ablative heat-preventing material, which was widely used for thermal protection systems [5][6][7][8].…”