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What is an ablative material?

asked 2016-05-14 22:50:54 -0600

anonymous user

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What is an ablative material that is used in heat shields for re-entry?

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answered 2016-05-21 22:12:26 -0600

Pascal Le Dramont gravatar image

Ablation is energy management through material consumption'

How an Ablator Works:

Hot gases in the boundary layer convectively heat the surface Radiant flux from the shock layer heat the surface Heat is either re-radiated out or conducted into the surface The polymer in the composite begins to decompose and pyrolysis gases are formed, carbon remains and a char layer begins to form The thermal front moves through the material, causing more decomposition The pyrolysis gases, formed deeper in the composite are at a lower temperature than the near surface char, so as they flow through the char, they cool it The charred surface reacts (oxidation, sublimation, etc) with the boundary layer and material is removed, causing recession (this may be either exo- or endothermic) As the pyrolysis and gases formed at the surface blow into the boundary layer, they thicken it and reduce the convective heating image description

Credit: Robin A. S. Beck, NASA Ames Research Center

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Asked: 2016-05-14 22:50:54 -0600

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Last updated: May 21 '16