Ablation model of EPDM insulator under high acceleration conditions (II) - Particle erosion model of ablative material considering the porous structure of charring layer hot launched missile

In this paper, charring layers microstructures of EPDM insulation in different erosion conditions were analyzed, and the charring layers were determined as gas-saturated porous media with dense layer and porous layer. Particle erosion was classified into two groups: mechanical erosion and particle heating increment. Mechanical erosion model was established by analyzing the structure of charring layer under various state parameters of particle erosion, and particle heating increment was obtained by experiment tests. The formation of dense layer inside the charring layer was fit to the theory of CVD. The particle erosion model was coupled with thermo-chemical model considering the porous structure of charring layer. The numerical results for different erosion conditions were found to reasonably agree well with the available experimental data, and the calculate structures of charring layer were almost consistent with the photos of microscope.