nkhani

Pakupanga zinthu zoteteza kutentha kwa zinthu zamlengalenga, pazinthu zomwe zimafuna makulidwe akuluakulu, zokhala ndi ma geometri ovuta, kapena zomwe zimakhala zosavuta kusweka, zinthu zophatikizana nthawi zambiri zimagwiritsidwa ntchito m'malo mwa zophimba zachikhalidwe zoteteza kutentha. Kuphatikiza apo, nyumba zoteteza kutentha zomwe zimakhala ndi ma composite zimapereka njira zosiyanasiyana zopangira: zimatha kupangidwa mwachangu pamalo otetezedwa kutentha, kapena zitha kulumikizidwa pamalopo pogwiritsa ntchito manja oteteza kutentha omwe adapangidwa kale, motero zimapereka zabwino zosiyanasiyana za njira yokonzekera bwino komanso yosavuta. Pakadali pano, zinthu zophatikizana zagalasi la phenolic zimagwiritsidwa ntchito kwambiri m'nyumba zoteteza kutentha chifukwa cha zabwino zake zambiri, kuphatikiza kukhazikika kwa kapangidwe kake, kukana kutentha kwambiri, kukolola kwakukulu, kutsika kwa ablation, mphamvu yayikulu yamakina, komanso kulimba kwabwino kwambiri.

Zosakaniza zagalasi la phenolic fiberAli ndi kuthekera kwakukulu kogwiritsidwa ntchito kwambiri m'gawo la ndege. Njira yawo yotetezera kutentha imaphatikizapo mgwirizano wa njira zambiri zotetezera, kuphatikizapo kuletsa kutentha, endothermic pyrolysis, kutentha komwe kumaperekedwa ndi char layer, ndi chithandizo cha kapangidwe kake. Pepalali lidzasanthula makamaka njira yotetezera kutentha kuchokera ku malingaliro a kuletsa kutentha, endothermic pyrolysis, ndi kutentha komwe kumaperekedwa ndi char layer.

1. Kuletsa Kutentha Kutulutsa Mphamvu

Mu phenolic glass fiber composites, phenolic resin matrix yokha ili ndi mphamvu yotsika ya kutentha, yomwe imathandiza kuchepetsa kutentha kwakunja. Pamene zinthu zophatikizika zimayikidwa pamalo otentha kwambiri omwe amakumana nawo paulendo, kutentha kumafalikira koyamba kuchokera kunja. Komabe, kapangidwe ka macromolecular chain komwe kali mu phenolic resin matrix kamalepheretsa njira zoperekera kutentha, zomwe zimapangitsa kuti kutentha kuchepe kwambiri. Nthawi yomweyo, kukhalapo kwa ulusi wagalasi mkati mwa composite kumasinthanso njira zoperekera kutentha mkati. Kuphatikiza apo, kulumikizana pakati pa ulusi wagalasi ndi phenolic resin kumawonetsa kukana kwakukulu kwa kutentha; chifukwa chake, kutentha kumakumana ndi kulepheretsa kwina pamene kudutsa mawonekedwe awa, kuletsa kwambiri njira yoperekera kutentha ndikuchepetsa bwino kuchuluka kwa kutentha mkati mwa zinthu zophatikizika.

2. Endothermic Pyrolysis

Ikakumana ndi malo akunja otentha kwambiri, phenolic resin imakumana ndi zochitika za pyrolysis mosalekeza. Njira iyi ya pyrolysis ndi endothermic reaction: ikatenga mphamvu ya kutentha, ma chemical bonds mkati mwa mamolekyu a phenolic resin amasweka, zomwe zimapangitsa kuti zinthuzo ziwole kukhala mpweya wa mamolekyulu ang'onoang'ono ndi zotsalira za carbonaceous. Njirayi imagwiritsa ntchito bwino mphamvu ya kutentha yomwe imasamutsidwa kuchokera kumalo akunja kupita pamwamba pa composite, motero nthawi yomweyo imatsitsa kutentha kwa pamwamba pa composite. 3. Kutentha Kuteteza Kudzera mu Char Layer

Pamene pyrolysis reaction ikupitirira, pang'onopang'ono char layer imapangidwa pamwamba paphenolic resin composite. Gawo la char ili lili ndi kapangidwe ka mapokoso, ndipo mapokoso ake odzaza ndi mpweya wosonyeza kutentha kochepa kwambiri; mawonekedwe awa amawonjezeranso mphamvu ya kutenthetsa kwa chinthu chopangidwacho. Nthawi yomweyo, gawo la char limapereka mawonekedwe olimba omwe amatha kupirira kupsinjika kwapadera kwa aerodynamic ndi katundu wamakina, motero amateteza zinthu zosapsa ku zotsatira za kukanda ndi kukokoloka kwa mpweya wotentha kwambiri. Gawo la char lomwe limapangidwa pamwamba pa chinthu chopangidwacho silimangogwira ntchito yotetezera kutentha kokha komanso, pamlingo winawake, limachepetsa kutayika kwa unyinji mu chinthu chopangidwacho, motero limakulitsa moyo wa ntchito ya kapangidwe ka chitetezo cha kutentha.