ʻOkoʻa nā pae mānoanoa o nā wai, nā mea wai a me nā mea kinoea o nā ʻano like ʻole. ʻO ka mānoanoa ka friction ma waena o nā molekala e hana ana i kahi wai. No laila, hana nā molekala i ka friction wai ke kahe ka wai. I loko o nā wai, hoʻokumu ʻia ka mānoanoa e nā ikaika cohesion (nā ikaika huki ma waena o nā molekala like). ʻOiai i loko o nā mea kinoea, hoʻokumu ʻia ka mānoanoa e nā kuʻi ʻana ma waena o nā molekala.
ʻOi aku ka maʻalahi o ke kahe ʻana o ka wai wai, no ka laʻana, ka wai. I ka ʻaoʻao ʻē aʻe, ʻoi aku ka paʻakikī o ke kahe ʻana o ka wai mānoanoa, no ka laʻana, ka lubricant. Hiki iā ʻoe ke hōʻoia ma ka ninini ʻana i ka wai a me ka lubricant ma luna o kahi ʻili hilig. ʻOi aku ka wikiwiki o ke kahe ʻana o ka wai ma mua o ka ʻaila. Pili pū ka pae o ka viscosity o ka wai i ka mahana. ʻO ke kiʻekiʻe o ka mahana o ka wai, ʻoi aku ka liʻiliʻi o ka viscosity o ka wai. No ka laʻana, i ka wā e palai ai ka makuahine i ka iʻa ma ka lumi kuke, ʻoi aku ka wai o ka ʻaila kuke i mānoanoa mua ke hoʻomehana ʻia. I ka ʻaoʻao ʻē aʻe, ʻoi aku ke kiʻekiʻe o ka mahana o kahi mea kinoea, ʻoi aku ka mānoanoa o ka mea kinoea.
Ka helu o ka viscosity
Hōʻike ka hōʻailona η i ka mānoanoa o ke kahe (heluhelu ʻia: eta). η = ke koina o ka mānoanoa. No laila, ua hōʻike ʻia ka pae mānoanoa o ka wai e ka koina mānoanoa o ka wai.
Hoʻokomo ʻia kahi papa wai lahilahi ma waena o 2 mau papa. ʻO ke kuʻikahi ka ikaika hoʻowalewale ma waena o nā molekala like, ʻoiai ʻo ka hoʻopili ʻana ka ikaika o ka huki ʻana ma waena o nā molekala like ʻole. Hana nā ikaika hoʻopili ma waena o ka papa a me ka papa wai i hoʻopili ʻia i ka papa (hoʻowalewale nā molekala wai a me nā molekala papa kekahi i kekahi). I kēia manawa, hana nā ikaika kuʻikahi ma waena o nā membrane wai (hoʻowalewale ka wai i nā molekala kekahi i kekahi).
I ka wā mua, ua hoʻomaha ka papa a me ka papa wai (kiʻi 1). Ma hope iho, ua huki ʻia ka papa ma luna i ka ʻākau (kiʻi 2). ʻAʻole i huki ʻia nā papa ma lalo (ua hoʻomaha ka papa lalo). Ua hoʻonohonoho ʻia ka nui o ka ikaika huki i hiki i ka papa ma luna ke neʻe i ka ʻākau ma ka wikiwiki mau (v mau). No ka mea aia kahi ikaika pipili e hana ana ma waena o ka lihi o ka papa a me ka ʻāpana o ka wai i hoʻopili ʻia i ka papa, neʻe pū ka wai ma lalo o ka papa i ka ʻākau. No ka mea aia kahi ikaika pili ma waena o nā molekole wai, ʻo ka wai e neʻe ana i ka ʻākau e huki i ka wai ma lalo.
ʻO ka ʻāpana o ke wai ma luna e huki i ke wai ma lalo e neʻe i ka ʻākau,
ʻoiai ʻo ka ʻāpana o ke wai ma lalo e paʻa ana i ke wai ma luna, no laila ʻokoʻa ka wikiwiki o ke wai. ʻO ka ʻāpana o ke wai ma luna e neʻe me ka wikiwiki nui (v), neʻe ka wai ma lalo me ka v liʻiliʻi, a pēlā aku. No laila, ʻo ka haʻahaʻa i lalo v, ʻo ka liʻiliʻi. I nā huaʻōlelo ʻē aʻe, loli mau ka wikiwiki o ka papa wai mai luna a lalo a hiki i ka l.
ʻO nā loli i ka wikiwiki o ka papa wai (v) i puʻunaue ʻia e ka mamao o ka loli (l) = v / l. Ua ʻike ʻia ʻo V/l ʻo ia ka gradient wikiwiki. Hiki i nā papa ma luna ke neʻe no ka mea aia kahi ikaika huki (F). No kekahi mau wai, ʻo ka nui o ka huki e pono ai ua kūlike pololei me ka ʻāpana o ka wai i hoʻopili ʻia i ka papa (A), ka wikiwiki o ka wai (v) a me ka kūlike ʻole me ka mamao l. Ma ke ʻano makemakika, hiki ke kākau ʻia penei:
Ma mua, ua wehewehe ʻia he maʻalahi ke kahe ʻana o kahi wai lahilahi, ʻoiai ʻoi aku ka paʻakikī o ke kahe ʻana o kahi wai mānoanoa. Hōʻike ka coefficient o ka viscosity i ka pae o ka viscosity o ka wai. Inā ʻoi aku ka mānoanoa o ka wai, ʻoi aku ka nui o ka ikaika tensile e pono ai. I kēia hihia, pili pono ka ikaika tensile i ka coefficient viscosity. Hiki ke kākau ʻia ma ke ʻano makemakika penei:
η = ke koina o ka mānoanoa, F = ka ikaika, l = ka mamao, A = ka ʻilikai, v = ka wikiwiki, ∝ = ka hoʻohālikelike
ʻO ke Anakahi ʻŌnaehana Honua (SI) no ke koina o ka viscosity ʻo Ns/m2 = Pa.s (pascal kekona). ʻO ke anakahi CGS (kenimika gram kekona) no ke koina viscosity ʻo dyn.s/cm2 = poise (P). Hōʻike pinepine ʻia ka viscosity ma centipoise (cP). 1 cP = 1/100 P. Hoʻohana ʻia ke anakahi poise no ka hoʻohanohano ʻana i kahi ʻepekema Farani, ʻo Jean Louis Marie Poiseuille (heluhelu ʻia: pwa-zoo-yuh).
1 kūlana kiʻekiʻe = 1 dyn. s/cm2 = 10 -1 Ns/ m2
