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مهندسی شیمی: مهندسی شیمی
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| Ablative Thermal Protection System |
| مولف |
دکتر محمدجواد مهدوی‌نژاد |
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| ناشر |
دانشگاه تربیت مدرس |
تاریخ انتشار |
1395 |
| نوبت چاپ |
اول |
تعداد صفحات |
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| قیمت پشت جلد |
250000 |
ارسال کننده |
admin |
| نوع جلد |
شومیز |
اندازه |
وزیری |
| کد DOI |
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کد دیویی |
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| کد ال سی |
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فایل کتاب |
- |
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توضیح
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Ablation is an effective and reliable method largely used in aerospace structures to protect the pay load from the damaging effects of external high temperatures. In the ablation process, the high heat fluxes are dissipated by the material through a series of endothermic processes. This finally leads to the loss and the consumption of the material itself. The ablative material keeps the surface temperature within a certain range, and as a consequence an increase of the heat flux will not cause a consistent temperature rise, but will bring about an increase of the surface recession rate.
Several limitations associated with the composite ablatives have motivated current efforts to identify next generation materials. Many times,the resulting chars are structurally weak and susceptible to mechanical erosion, severely reducing the lifetime of the insulator or necessitating additional insulation thickness.
Polymer layered silicate nanocomposites show excellent potential as ablative materials because upon pyrolysis, the organic–inorganic nanostructure reinforcing the polymer can be converted into a uniform ceramic layer, which may lead to significantly higher resistance to oxidation and mechanical erosion in compare to composite ablative materials.Furthermore, provided that the char remains intact, resistance to thermal and chemical ablation ultimately limits lifetime and performance.
The mathematical model can forecast the thermal decomposition, thermophysical properties changes and ablation of the polymer layered silicate nanocomposite. Inverse solution analysis technique is used to model the nanocomposite ablation process and calculate the effective thermal diffusivity. Around the time this most general thermal response model and research is introduced, the effect of high heat flux on ablative polymer layered silicate nanocomposite performance is studied. Herein, the principle of design and evaluation of insulation performance of polymer layered silicate nanocomposites are also discussed
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