Composite materials, such as phenolic resins, are often used for thermal protection in an atmospheric re-entry spacecraft. We investigate the use of similar systems for combustion by using a McKenna burner to create a steady, flat premixed laminar flame that interacts with test materials above the burner surface [1]. Both the pyrolysis reactions of resins due to aerodynamic heating and the ablation of charred materials contribute significantly to the insulation of the combustor wall by absorbing thermal energy. This configuration does allow a controlled assessment of combustion-wall interaction and consequent degradation of the test samples without the complexity of turbulent reacting flows and supersonic combustion. Therefore, this study focuses on the modeling of heat-protection materials, and a validation of its coupling with a combustion solver against experiments. Many uncertain parameters are present in the model, such as parameters in combustion kinetics, oxidation-pyrolysis kinetics, effective thermal conductivity in composite materials [2], and surface radiation. The input uncertainties from these parameters all contribute to the total uncertainty of our Quantities of Interest (QoI’s), i.e., mass loss and temperature. The multiphysics coupling makes the system particularly challenging for UQ and validation efforts. A simplified 1D wall recession model will be used to assist an initial sensitivity analysis and model selection. We will then perform a computationally more challenging study for an axisymmetric flat flame burner model. References [1] Tulio R. Ricciardi, Kunkun Tang, and Jonathan B. Freund. Analysis of thermal protective systems in combustor environments. Proceedings of the 13th Ablation Workshop, 2023. [2] Kunkun Tang, Francesco Panerai, and Jonathan B. Freund. Sensitivity analysis for effective conductivity of anisotropic fibrous materials. UNCECOMP Proceedings, pages 511–525, 2023. ISSN 2623-3339. doi:https://doi.org/10.7712/120223.10354.19852.