A volumetric ablation model of EPDM considering complex physicochemical process in porous structure of char layer
| Autor: | Yu Xiaojing, Liu Yang, Li Jiang, Li Qiang, Ma Jian-Ming, Yang Sa, Guan Yi-Wen |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Materials science
QC1-999 medicine.medical_treatment General Physics and Astronomy 02 engineering and technology 010402 general chemistry 01 natural sciences porous media medicine ethylene-propylene-diene monomer 47.56.+r Char volumetric ablation Porosity 44.30.+v Physics ablation model 021001 nanoscience & nanotechnology Ablation 0104 chemical sciences solid rocket motor Chemical engineering Scientific method 0210 nano-technology Porous medium Layer (electronics) Ethylene-propylene-diene-monomer |
| Zdroj: | Open Physics, Vol 15, Iss 1, Pp 344-353 (2017) |
| ISSN: | 2391-5471 |
| DOI: | 10.1515/phys-2017-0038 |
| Popis: | A volumetric ablation model for EPDM (ethylene- propylene-diene monomer) is established in this paper. This model considers the complex physicochemical process in the porous structure of a char layer. An ablation physics model based on a porous structure of a char layer and another model of heterogeneous volumetric ablation char layer physics are then built. In the model, porosity is used to describe the porous structure of a char layer. Gas diffusion and chemical reactions are introduced to the entire porous structure. Through detailed formation analysis, the causes of the compact or loose structure in the char layer and chemical vapor deposition (CVD) reaction between pyrolysis gas and char layer skeleton are introduced. The Arrhenius formula is adopted to determine the methods for calculating carbon deposition rate C which is the consumption rate caused by thermochemical reactions in the char layer, and porosity evolution. The critical porosity value is used as a criterion for char layer porous structure failure under gas flow and particle erosion. This critical porosity value is obtained by fitting experimental parameters and surface porosity of the char layer. Linear ablation and mass ablation rates are confirmed with the critical porosity value. Results of linear ablation and mass ablation rate calculations generally coincide with experimental results, suggesting that the ablation analysis proposed in this paper can accurately reflect practical situations and that the physics and mathematics models built are accurate and reasonable. |
| Databáze: | OpenAIRE |
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