KY EPSCoR: FY21: NASA: RID Project: A Stochastic Approach to Permeability and Tortuosity Modeling Using Experimental Flow Tube Measurements - Match for 3200002377

A stochastic approach to permeability and tortuosity modeling using experimental ?ow tube measurements Michael W. Renfro (PI) University of Kentucky, Lexington, KY, 40506 Abstract Low-density ablative materials commonly used for thermal protection system (TPS) are composed of a porous structure. These materials, while appearing homogeneous at the macroscale, consist of disordered arrangements of ?bers. As such, TPS materials are intrinsically inhomogeneous, and their thermal, mechanical and chemical properties at the mesoscale are non-uniform. This proposal aims at measuring the tortuosity and the permeability of the material in a way that takes into account this particularity. To do so, a ?ow tube facility will be updated at the University of Kentucky to measure tortuosity and temperature dependent permeability. At ?rst, the FiberForm material – a commercial carbon preform used for manufacturing TPS – will be used. More complex material, such as AVCOAT, PICA and Asterm, with then be measured. These measurements will allow the implementation of a stochastic model in material response codes, and will thus provide a more realistic property description, which in turn, will generate more accurate thermal response prediction. 1