Mphamvu kukhuthala madzimadzi. Kodi tanthauzo lake thupi ndi makina?

madzi limanenedwa ngati thupi, ndi mphamvu kusintha mawonekedwe ake pa chikoka amangosankha ang'onoang'ono. Kawirikawiri pali mitundu iwiri chachikulu cha zakumwa ndi mpweya kukapanda kuleka. Kukapanda kuleka madzimadzi - magazi m'njira mwachizolowezi: madzi, mafuta a nyale, mafuta ndi zina zotero. Gaseous madzi - mpweya umene m'mikhalidwe yachibadwa Mwachitsanzo, zinthu gaseous monga mpweya, asafe, propane, oxygen.

mankhwala awa amasiyana dongosolo maselo ndi mtundu wa mogwirizana kwa mamolekyulu ndi mzake. Komabe, kuchokera amazionera a zimango, ali mosalekeza TV. Ndipo chifukwa cha ichi, chifukwa iwo anazindikira kuti ena ofanana makhalidwe makina: kachulukidwe ndi mphamvu yokoka yeniyeni; ndi zofunika thupi katundu: compressibility yolalikira ikukhudzana kulimba kwamakokedwe, mphamvu ya mavuto padziko ndi kukhuthala.

Pansi kukhuthala kumvetsa chuma cha chinthu madzi kukana kutsetsereka kapena kuloza zigawo zake kwa wina ndi mzake. Akamanena za mfundo ndi pakutchulidwa wa asilikali mikangano pakati pa zigawo zosiyana mkati madzimadzi pa zoyenda awo wachibale. Kusiyanitsa pakati pa mfundo yonena za "zazikulu kukhuthala madzimadzi" ndiponso "kayendedwe kukhuthala". Kenako, tione, kodi pali kusiyana pakati pa mfundo imeneyi.

mfundo zikuluzikulu ndi gawo

Viscous mphamvu F, lomwe likutuluka kusasankha wachibale wina ndi mzake zigawo moyandikana wa madzimadzi zowombetsa mkota ndi mwachindunji njila kwa mathamangidwe zigawo ndi chokhala m'dera S. Izi zochita mphamvu malangizo ndi perpendicular kwa anayambitsa, ndipo anasonyeza mwa Newton aone kuti pali ndi analytically

F = μS (ΔV) / (Δn),

kumene (ΔV) / (Δn) = GV - mathamangidwe ndi masinthidwe amtundu mu dera wachibadwa zigawo avundulidwe.

The Kugwirizana koyefishienti μ - ndi kukhuthala zazikulu, kapena kungoti kukhuthala zowombetsa mkota madzimadzi. Kuyambira maikwezhoni Newton ndi

μ = F / (S ∙ GV).

Mu thupi muyeso dongosolo unit wa kukhuthala amatanthauziridwa kuti kukhuthala sing'anga, imene pa wagawo mathamangidwe masinthidwe amtundu GV = 1 cm / gawo pa centimeter lalikulu la wosanjikiza frictional mphamvu amachita 1 dyne. Motero, gawo la wagawo mu dongosolo imeneyi yafotokozedwera dynes ∙ m ∙ masentimita ^ (- 2) = r Mukhoza ∙ masentimita ^ (- 1) ∙ m ^ (- 1).

Izi muyeso amatchedwa zazikulu kukhuthala poise (P).

1 P = 0.1 Pas ∙ m'ma = 0,0102 kgf ∙ ndi ∙ mamita ^ (- 2).

Ikani ndi mayunitsi ang'onoang'ono, akuti: P 1 = 100 centipoises (cps) = 1000 mPas (millipuaz) = 1000000 Inc (mikropuaz). Mu dongosolo luso kwa unit wa mtengo kukhuthala kutenga kgf ∙ ndi ∙ mamita ^ (- 2).

Mu dongosolo lonse unit wa kukhuthala amatanthauziridwa kuti kukhuthala sing'anga, imene pa wagawo mathamangidwe masinthidwe amtundu GV = 1 m / s 1 mita pa mita lalikulu la madzi wosanjikiza akuchita mikangano mphamvu ya 1 N (Newton). The gawo mfundo za μ mu la SI yafotokozedwera makilogalamu ∙ mamita ^ (- 1) ^ ∙ ndi (- 1).

makhalidwe Komanso monga mfundo zazikulu kukhuthala madzi anayambitsa ngati chiŵerengero cha kinematic kukhuthala koyefishienti μ kwa kachulukidwe madzimadzi. Mtengo wa kukhuthala kinematic amayezedwa Stokes (1 Maphunziro = 1 cm ^ (2) / c).

The kukhuthala koyefishienti ndi numerically wofanana ndi chiwerengero cha magalimoto nazo mpweya kusunthira pa nthawi wagawo malangizo ndi perpendicular kwa gululi, pa malo wagawo pamene kayendedwe liwiro losiyana pa unit wa mathamangidwe mu zigawo mpweya anapambulwa pa kutalika unit. Kukhuthala koyefishienti zimatengera mtundu ndi chikhalidwe cha chuma (kutentha ndi kuthamanga).

Mphamvu kukhuthala ndi kukhuthala kinematic zakumwa ndi mipweya, Pamlingo waukulu zimadalira kutentha. Anazindikira kuti onse koyefishienti kuchepa ndi kuwonjezeka kutentha sukulu madzi ndi, Tikawonetsetsa amayamba kutentha limatuluka - kwa mpweya. Mosiyana ndi kudalira izi zingathe kufotokozedwa ndi chikhalidwe thupi la mogwirizana kwa mamolekyulu mu zakumwa droplet ndiponso gasi.

Tanthauzo thupi

Ku maganizo a chiphunzitso maselo kayendedwe mpweya kukhuthala chodabwitsa kwagona kuti ikuyenda sing'anga chifukwa lamulo mwachisawawa mamolekyulu amapezeka zigawo mayikidwe a imathamanga osiyana. Choncho, ngati wosanjikiza yoyamba malangizo ukuyenda mofulumira kuposa pafupi thereto wosanjikiza chachiwiri, wosanjikiza woyamba wa wachiwiri kusuntha mofulumira molekyulu, ndi mosemphanitsa.

Choncho, wosanjikiza woyamba amamuchititsa imathandizira kayendedwe ka wosanjikiza chachiwiri, ndipo chachiwiri - yobwerera kayendedwe ka woyamba. Choncho, chiwerengero cha kayendedwe ka wosanjikiza woyamba adzakhala ndichepe, ndipo chachiwiri - kuonjezera. Kusintha chifukwa wambiri izi za kayendedwe amakhala ndi kukhuthala koyefishienti ku mipweya.

The droplet mosiyana mipweya, ndi mikangano mkati mwa mokulirapo ndi zochita za asilikali intermolecular. Ndipo, kuyambira mtunda pakati mamolekyulu wa droplet madzi ndi yaing'ono poyerekeza ndi mapangidwe a gaseous, ndi maselo mogwirizana mphamvu pamene - kwambiri. Mamolekyulu wa madzi, komanso mamolekyulu wa zolimba, kuyambira pafupi mfundo mgwirizano. Komabe, zakumwa, zinthu zimenezi si n'kupuma. Patapita nthawi zina nthawi madzi molekyulu mwadzidzidzi ku malo atsopano. Pa nthawi yomweyo, imene udindo wa mamolekyulu mu madzi sasintha, nthawi anaitcha "Kukwatiwa moyo".

mphamvu Intermolecular zimadalira kwambiri pa mtundu wa madzi. Ngati kukhuthala thunthu ndi laling'ono, amatchedwa "flowable", monga otaya koyefishienti ndi kukhuthala wochitachita wa madzimadzi - ndi inversely njila. Tikawonetsetsa zakuthupi ndi kukhuthala mkulu angakhale ndi kuuma makina, monga Mwachitsanzo, utomoni. The kukhuthala thunthu pamene kwambiri zimadalira zikuchokera zosafunika ndi ndalama zawo ndi kutentha. Ndi kukula kutentha kuchuluka "amangokhala moyo" nthawi yafupika, potero kukula madzimadzi kukhuthala amachepetsa ndi kuyenda ndi zinthu.

Chodabwitsa kukhuthala, komanso zina zochitika maselo zoyendera (mayamwidwe ndi matenthedwe madutsidwe) ndi ndondomeko sizingasinthe imbaenda kupambana ya mgwirizano boma lolingana mphamvu zosagwiritsika ntchito pazipita ndi ufulu mphamvu zochepa.