Refinement of chemical kinetics models for carbon ablation

Institut

Lehrstuhl für Thermodynamik (TUM-ED)

Typ

Masterarbeit /

Inhalt

 

Beschreibung

When faced with extreme aerothermal environments, such as hypersonic air travel or earth reentry, ablative thermal protection systems (TPS) are often required to ensure heat shielding for operationally important components. One example of this is Carbon Fiber Reinforced Carbon (CFRC), which has found application on the nosecone and leading edges of the space shuttle. Mainly due to mass budget constraints, but also aerodynamic surface changes in the case of sustained hypersonic flight, knowledge of the required amount and distribution of TPS is paramount to mission success. As such, mathematical models to predict the ablation rate and mechanics have been a topic of discussion since the previous century. Due to the conflicting interests of keeping computational power low (both due to costs and availability) and desiring as accurate results as possible, as well as the hypersonic extreme aerothermal environment causing traditional Navier-Stokes based continuum mechanics to deviate from observed results, even established CFRC/Carbon ablation models show significant disagreements with one another. Beyond this, the interaction between the material porosity of Carbon-based ablator materials and the ablation process is somewhat poorly understood and sparingly researched, causing further discrepancies. More recently, experiments based on molecular beam trials have attempted to address some of these concerns. Attempting to further address these problems, a pore-scale investigation of carbon material ablation based on these molecular beam experiments is conducted. Within this project, the goal is to create a more refined chemical kinetics framework based on both the physics of the hypersonic environment as well as the experimental data available. Key tasks include research and simulation of: 

• Simulation and investigation of bulk-molecular surface reactions 

• Gas-phase second-step reactions and their impact on surface-phase molecule availability 

• Changes in the local thermal environment due to chemical bond breakage/formation 

• Modelling of air-to-surface heat- and molecule transfer in hypersonic conditions for ablation boundary conditions

Simulations will be conducted mostly on the continuum level, potentially complemented by DSMC simulations.

Voraussetzungen

• M.Sc. student in Aerospace Engineering, Mechanical Engineering, Physics, or related field. 

• Experience with simulation or programming tools (Python, MATLAB, or similar) 

• Basic familiarity with reaction kinetics

• Experience with hypersonic environments is a benefit, but not required

Möglicher Beginn

immediately

Kontakt

M.Sc. Niclas Albrecht
Raum: 5507.EG.706
Tel.: +49 89 289 16596
niclas.albrechttum.de