Thermal Conductivity Characterization of Low-density Volumetric Ablators

In the field of atmospheric entry, the e?ective thermal conductivity of a given vol- umetric ablator is modeled through the relationship proposed by Moyer and Rindal at Aerotherm (CMA), in the 1960's. This relationship has been widely accepted and used in material response codes throughout the hypersonic entry community even though no literature explicitly validates the model using experimental data. As shown in uncer- tainty quantification studies, material response solutions - which are used to design and ensure the overall safety of a spacecraft - are heavily driven by the materials' ef- fective thermal conductivity values. It is for these reasons, that this study is proposed. The present study aims to provide experimental elective thermal conductivity data for volumetric decomposing ablators which will ultimately be used to validate or invalidate, the CMA thermal conductivity model. The goal of the proposed additional task is to further increase the fidelity of ablation modeling by validating permeability models. These permeability measurements will complement the conductivity measurements already performed in the main tasks and will allow to complete the models. To limit the scope of this task, the permeability at room temperature will be measured. However, the design will allow to eventually include a furnace so that high temperature measurements could be obtained. It is expected that the apparatus will be put together in two months, and that the relevant data will be collected within the following two months. As with the other tasks of award, this additional task will mainly be performed by Dr. Thomas J. Cochell, as well as with an undergraduate student.