Experimental and Numerical Evaluation of the Ablation Process of Carbon/Carbon Composites Using High Velocity Oxygen Fuel System

Abstract

The ablation process of carbon/carbon (C/C) composites was tested under hypersonic flowing propane flame. The microstructures of C/C composites were characterized and the numerical analysis was performed. Two typical ablation morphologies of the carbon fibers, which are drum-like and needle-like shapes, were observed depending on the alignments of fibers to the flame directions. Temperature fields in the composites were analyzed using finite element method, and the mechanisms that govern the formation of different ablation behaviors were elucidated. For paralleled fiber bundles, the highest temperature situates in the middle parts underlying the ablation pits, where the drum-like shape is formed. For perpendicular fiber bundles, the highest temperature appears at the turning point between the transverse section and the surface of fiber, which leads to the gradual ablation from the fiber surface toward the axis, and eventually the formation of the needle-like shape.

Fast Calculation Method for Predicting the Morphology of Steady-State Ablation

“…Carbon matrix can also be reconstructed in the same way as carbon fibers. Figure 11a shows the SEM morphology of the C/C composites [31]. A simplified section of the fibers and matrix was established by observing the red rectangular area of the SEM morphology, as shown in Figure 11b.…”

“…The results showed that the fibers and matrix were exposed to the atmospheric environment, and there was a thin reactive interphase between the fiber and matrix [25][26][27][28][29][30]. Fan et al [31,32] discovered the needle shapes and sheath package structures of composites, following ablation using a hypersonic flowing propane torch. The reasons for the microstructural evolution of the C/C and C/C-SiC composites were discussed and analyzed using ANSYS Fluent software.…”

Microstructure-Based Thermochemical Ablation Model of Carbon/Carbon-Fiber Composites

“…It changes not only the volume fraction of carbon fiber but also the fiber orientation and void volume fraction. Due to the different characteristics of the fibers and matrix [15,16], these microstructural changes have a great impact on the thermochemical ablation behavior. To reveal the ablation mechanisms, it is important to investigate the thermochemical ablation behavior of carbon/carbon composites at the micro scale.…”