Experimental Investigation of In-Plane Ablation in Thermal Protective System Materials

During atmospheric entry, a capsule experiences extreme aerodynamic heating, necessitating the use of an ablative thermal protective system (TPS) to shield its payload. However, the surface recession of TPS materials is not perfectly uniform, leading to significant in-plane heating effects that are currently underpredicted by existing ablative modeling software. A more accurate understanding of in-plane ablation rates is crucial for improving predictive capabilities. Due to the high cost and unpredictability of reentry missions, ground-based testing is essential for acquiring experimental data. This study utilizes the High Enthalpy Low-Cost Multi-Use Torch (HELMUT) at the University of Kentucky to investigate in-plane ablation behavior in Fiberform®, a porous carbon fiber matrix. When orthogonally cut samples are tested, the mass and volumetric loss can be analyzed to examine heat flow through the material layers and its contribution to particle spallation and ablation rates. These findings aim to enhance the accuracy of material ablation models for future atmospheric entry applications.