Visualization of Particle Packing Structure of AP/HTPB Composite Propellant by 3D X-ray CT Image Analysis

View Video Presentation: https://doi.org/10.2514/6.2023-1690.vid

AP/HTPB composite propellant is one of the most commonly used solid propellants: it is a cured high-viscosity slurry made by mixing AP particles and Al powder with HTPB as a binder. Mechanical and combustion characteristics of the propellant are influenced by the dispersion state of the tightly packed AP particles and the gaps between the particles. In this study, we suggest an image analysis method to visualize the particle packing structure in a sample using X-ray CT images of KCl/HTPB simulated propellants. By extracting the region where KCl particles are most likely to be presented according to their luminance value in the CT image and isolating particle clumps by Watershed algorithm, we could distinguish 16,000 particles in the sample. Also, this method can measure the centroid coordinate of AP particles and evaluate their volumes and sizes. The particle size distribution was bell-shaped with the highest point at 530μm, which was similar to the distribution obtained by the optical diffraction scattering methods.