Combustion-ablation time scale phenomenology

The thermal protective systems designed for atmospheric reentry are analyzed through sub-mechanisms to understand the multiphysics of integrated structures and inform design choices for scramjet combustors and material optimization. Through the interaction of different mechanisms acting on different time scales, the phenomenology for material degradation of carbon fiber ablators is studied numerically. A simple one-dimensional model was an appropriate first step for analysis of the thermal conduction and oxidation of the material, with nonlinear implicit methods, that facilitate solutions with widely disparate time scales. The numerical solution was verified through a method of manufactured solutions. The model was then expanded, coupling additional physical mechanisms into the system including mass conservation, oxygen transport, and advective velocity within the porous media, thus creating a thermal boundary layer, limiting material oxidation. The different time regimes allow for the comparison of non-dimensional ratios that produce drastically different behaviors for the system. By developing an understanding of multiphysics interactions with time scales for the combustor, optimized design and material constraints can be quickly and affordably determined for experimentation.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Aerospace Engineering

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Brown, Julia K.

Contributors dc:contributor

• Freund, Jonathan B

• TPS
• MMS
• Numerical Methods
• Newton Solver
• CEESD
• Implicit Method, Aerospace
• Scramjet

Statement dc:rights

• Copyright 2025 Julia Brown

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129284

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129284