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I ka hoʻolālā palekana wela o nā huahana aerospace, no nā ʻāpana e koi ana i ka mānoanoa nui, nona nā geometries paʻakikī, a i ʻole ka hiki ke hoʻopilikia ʻia e ka haki ʻana o ke kaumaha, hoʻohana pinepine ʻia nā mea hui ma ke ʻano he pani no nā uhi pale wela kuʻuna. Eia kekahi, hāʻawi nā ʻano pale wela hui i nā koho hana like ʻole: hiki ke hana koke ʻia ma luna o kahi palekana wela kikoʻī, a i ʻole hiki ke hoʻopaʻa ʻia i kahi me ka hoʻohana ʻana i nā ʻeke pale wela hui mua, no laila e hāʻawi ana i nā pono kūikawā o kahi kaʻina hana hoʻomākaukau kūpono a maʻalahi. I kēia manawa, hoʻohana nui ʻia nā composites fiber phenolic i nā ʻano pale wela ma muli o ko lākou mau pono he nui, me ke kūpaʻa o ke ʻano, ke kūpaʻa wela kiʻekiʻe, ka hua char kiʻekiʻe, ka wikiwiki ablation haʻahaʻa, ka ikaika mechanical kiʻekiʻe, a me ka paʻakikī hopena maikaʻi loa.

Nā hui pū ʻia o ke aniani phenolicLoaʻa i kēia pepa ka hiki ke hoʻohana nui ʻia i loko o ka ʻāpana aerospace. ʻO kā lākou ʻano pale wela e pili ana i ka pilina synergistic o nā kaʻina hana pale he nui, me ka pale ʻana i ka hoʻoili wela, ka pyrolysis endothermic, ka insulation thermal i hāʻawi ʻia e ka papa char, a me ke kākoʻo kūkulu. E kālailai mua kēia pepa i ka ʻano pale wela mai nā manaʻo o ka pale ʻana i ka hoʻoili wela, ka pyrolysis endothermic, a me ka insulation thermal i hāʻawi ʻia e ka papa char.

1. Ka pale ʻana i ka hoʻoili wela

I loko o nā hui fiber aniani phenolic, loaʻa i ka matrix resin phenolic kahi conductivity thermal haʻahaʻa maoli, kahi e hoʻopaneʻe nui ai i ka hoʻoili ʻana o ka wela o waho. Ke hoʻokomo ʻia ka mea hui i nā wahi wela kiʻekiʻe i loaʻa i ka wā lele, hoʻolaha mua ka wela i loko mai ka ʻili waho. Eia nō naʻe, ʻo ke ʻano kaulahao macromolecular i loko o ka matrix resin phenolic e ālai ana i nā ala o ka hoʻoili wela, a laila e hōʻemi nui ʻia ai ka wikiwiki o ka hoʻoili wela. I ka manawa like, ʻo ke alo o nā fibers aniani i loko o ka hui e hoʻololi hou i nā ala hoʻoili wela o loko. Eia kekahi, hōʻike ka interface ma waena o nā fibers aniani a me ka resin phenolic i ke kū'ē wela kiʻekiʻe; no laila, loaʻa i ka wela ka impedance hou aʻe i kona hele ʻana ma kēia interface, e kāohi hou ana i ke kaʻina hana hoʻoili wela a hoʻohaʻahaʻa pono i ka wikiwiki o ka piʻi ʻana o ka mahana i loko o ka mea hui.

2. Pyrolysis Endothermic

Ke hōʻike ʻia i nā wahi waho wela kiʻekiʻe, hana ka resin phenolic i nā hopena pyrolysis mau. He hopena endothermic kēia kaʻina hana pyrolysis: ma hope o ka omo ʻana i ka ikehu wela, haki nā pilina kemika i loko o nā molekole resin phenolic, e hoʻoheheʻe ana i ka mea i nā kinoea molekole liʻiliʻi a me nā koena carbonaceous. Hoʻopau pono kēia kaʻina hana i ka ikehu wela i hoʻoili ʻia mai ke kaiapuni waho a i ka ʻili o ka composite, a laila e hoʻohaʻahaʻa pū ana i ka mahana o ka ʻili o ka mea composite. 3. Hoʻopaʻa Thermal ma o ka Char Layer

I ka hoʻomau ʻana o ka hopena pyrolysis, e hana mālie ana kahi papa char ma luna o ka ʻili ohui pū ʻia o ka resin phenolic. Loaʻa i kēia papa ʻā kahi ʻano porous, me kona mau pores i piha i nā kinoea e hōʻike ana i ka conductivity thermal haʻahaʻa loa; hoʻonui hou kēia hiʻohiʻona i nā hiki insulation thermal o ka composite. I ka manawa like, hōʻike ka papa ʻā i kahi ʻano ʻili paʻakikī e hiki ke kū i nā kaomi aerodynamic kikoʻī a me nā ukana mechanical, no laila e pale ana i ka mea i hoʻopau ʻole ʻia mai nā hopena scouring a me ka erosion o nā kahe kinoea wela kiʻekiʻe. ʻO ka papa ʻā i hana ʻia ma ka ʻili composite ʻaʻole wale e lawelawe i kahi hana insulating akā, i kekahi ʻano, e hōʻemi ana i ka pohō nui i loko o ka composite, no laila e hoʻolōʻihi ana i ke ola lawelawe o ka hale pale thermal.