Ablative materials are required for the most demanding atmospheric reentry missions. These materials are often carbon fibers embedded in a phenolic polymer matrix. At high temperature, phenolic undergoes pyrolysis where the polymer is transformed into a pure carbon solid called char. There is currently no robust computational methodology for pyrolysis to guide improvement in thermal protection system (TPS) materials or make predictions of TPS performance under operating conditions.
Many NASA missions, including crewed missions to Mars, are not possible with current ablative materials. This project will examine different computational methods to model pyrolysis of phenolic to guide/accelerate development of novel materials and understand their behavior under operating conditions.
Computational modeling will enable the rapid and efficient development of the next generation of high performance ablators that are critical for NASA entry vehicles. Pyrolysis of phenolic polymers, for example, is a chemically reactive process fundamental to ablative TPS, but the basic chemistry of pyrolysis is not well understood. Improved understanding will (1) facilitate the design of new, novel ablative materials and (2) improve material response models used for TSP design.
The principal product of this project will be an assessment of simulation methodologies for phenolic pyrolysis. A new capability with these methods can then be applied to a range of problems in computational modeling of ablative materials.