Download or read book Characterisation of Ablative Thermal Protection System Materials Through Analysis and Inverse Methods written by Sara Pavesi and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The complex and non-linear nature of ablation processes makes a systematic comparative analysis of ablators a challenging task. Within this thesis work, several approachesare adopted to investigate the ablative material performance and thermodynamics of the ablation process. Contemporary European ablators tested at IRS, together with already flown ablators, are analyzed and compared with respect to their performance. From this analysis, several considerations for an ablative thermal protection system performance optimization are formulated and discussed. Furthermore, a method for solving in-depth and surface energy equations and deriving a first approximation of the weight of each energy term is presented. A physical model which divides a charring ablator into different layers based on the thermochemical processes occurring withineach layer is adopted. Interpolating pyrometric and thermocouples measurements, spatial and temporal temperature distributions of lightweight ZURAM are evaluated.This ablator is developed by the German Aerospace Center in Stuttgart and tested under relevant re-entry conditions. From the resulting temperature profiles, partial derivatives terms of the in-depth energy equations are estimated for each layer and, consequently, the energy equations are solved. This method enables to evaluate energy terms which are generally difficult to assess due to the high complex natureof the boundary layer and the TPS environment, such as diffusive energy fluxes fromboundary layer gases. Lastly, spatial and temporal distributions and pyrolysis layer thickness evaluated interpolating ZURAM test data are compared with results froma finite element method simulation to investigate the effect of volume ablation.*****The complex and non-linear nature of ablation processes makes a systematic comparative analysis of ablators a challenging task. Within this thesis work, several approachesare adopted to investigate the ablative material performance and thermodynamics of the ablation process. Contemporary European ablators tested at IRS, together with already flown ablators, are analyzed and compared with respect to their performance. From this analysis, several considerations for an ablative thermal protection system performance optimization are formulated and discussed. Furthermore, a method for solving in-depth and surface energy equations and deriving a first approximation of the weight of each energy term is presented. A physical model which divides a charring ablator into different layers based on the thermochemical processes occurring withineach layer is adopted. Interpolating pyrometric and thermocouples measurements, spatial and temporal temperature distributions of lightweight ZURAM are evaluated.This ablator is developed by the German Aerospace Center in Stuttgart and tested under relevant re-entry conditions. From the resulting temperature profiles, partial derivatives terms of the in-depth energy equations are estimated for each layer and, consequently, the energy equations are solved. This method enables to evaluate energy terms which are generally difficult to assess due to the high complex natureof the boundary layer and the TPS environment, such as diffusive energy fluxes fromboundary layer gases. Lastly, spatial and temporal distributions and pyrolysis layer thickness evaluated interpolating ZURAM test data are compared with results froma finite element method simulation to investigate the effect of volume ablation.