Numerical modeling of charring ablative thermal protection systems under aerodynamic heating

Coşkun, Volkan
In this thesis study, comprehensive modeling of charring ablative materials subjected to aerodynamic heating is considered. The aim of this work is to develop a material response solver that allows predicting the response of charring ablative materials which are used as thermal protection systems in aerospace applications under different complexity levels. Detailed description of the governing equations and the novel method employed to solve them are given. The developed solver provides a versatile environment for engineering analyses and incorporates a third-party library for the evaluation of thermodynamic and transport properties of the pyrolysis gas mixture and chemical kinetics, if necessary. The two-equation model is used to model the thermal non-equilibrium between the solid and the gas phases, and the reactor network approach is adopted for modeling pyrolysis gas flow inside the porous ablative material. Usage of reactor network approach provides many advantages. Simulations with different gas compositions and reaction mechanisms can be carried out easily. In addition, it allows increasing the fidelity of the code such as future implementation of heterogeneous reactions to describe the pyrolysis decomposition. Correctness and the accuracy of the numerical implementation is ensured by conducting various verification and validation studies. Effects of chemical and thermal non-equilibrium and influence of pore structure parameters, i.e. porosity and permeability, on the response of charring ablative materials are explored.


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Citation Formats
V. Coşkun, “Numerical modeling of charring ablative thermal protection systems under aerodynamic heating,” Ph.D. - Doctoral Program, Middle East Technical University, 2022.