Nws paub tias txhua yam uas nyob ib puag ncig tus neeg, suav nrog nws tus kheej, yog lub cev uas muaj cov khoom. Cov, nyob rau hauv lem, yog tsim los ntawm molecules, tom kawg los ntawm atoms, thiab lawv yog los ntawm txawm me me qauv. Txawm li cas los xij, qhov sib txawv nyob ib puag ncig zoo heev uas nws nyuaj rau xav txog txawm tias qee yam kev sib txawv. Thiab muaj. Cov khoom sib xyaw ua ke hauv ntau lab, txhua tus ntawm lawv yog qhov tshwj xeeb hauv cov khoom, qauv thiab lub luag haujlwm. Nyob rau hauv tag nrho, ob peb lub xeev muaj qhov txawv, raws li tag nrho cov tshuaj muaj peev xwm correlated.
xeev xwm txheej
Muaj plaub txoj kev xaiv rau lub xeev sib sau ua ke.
- Gases.
- Solids.
- kua.
- Plasma yog cov roj ionized tsawg heev.
Nyob rau hauv tsab xov xwm no peb yuav txiav txim siab txog cov khoom ntawm cov kua dej, lawv cov yam ntxwv thiab cov kev ua tau zoo.
Kev faib cov kua cev
Qhov kev faib tawm no yog ua raws li cov khoom ntawm cov kua dej, lawv cov qauv thiab cov qauv tshuaj, nrog rau cov hom kev sib cuam tshuam ntawm cov khoom uas ua rau cov compound.
- Cov kua dej li no uas muaj cov atom tuav ua ke los ntawm Van der Waals rog. Piv txwv yog cov kua roj (argon, methane thiab lwm yam).
- Cov khoom uas muaj ob lub atom zoo tib yam. Piv txwv: liquefied gases - hydrogen, nitrogen, oxygen thiab lwm yam.
- Kua hlau - mercury.
- Cov khoom muaj xws li cov khoom txuas los ntawm covalent polar bonds. Piv txwv li: hydrogen chloride, hydrogen iodide, hydrogen sulfide thiab lwm yam.
- Cov tshuaj uas muaj hydrogen bonds tam sim no. Piv txwv li: dej, cawv, ammonia hauv kev daws.
Tseem muaj cov qauv tshwj xeeb - xws li cov kua siv lead ua kua, cov kua uas tsis yog-Newtonian, uas muaj cov khoom tshwj xeeb.
Peb yuav txiav txim siab txog cov khoom tseem ceeb ntawm cov kua uas txawv ntawm lwm lub xeev ntawm kev sib sau. Ua ntej tshaj plaws, cov no yog cov uas feem ntau hu ua lub cev.
Cov khoom ua kua: zoo thiab ntim
Nyob rau hauv tag nrho, kwv yees li 15 tus yam ntxwv tuaj yeem paub qhov txawv uas tso cai rau peb piav qhia tias cov khoom hauv nqe lus nug yog dab tsi thiab lawv cov nqi thiab cov yam ntxwv yog dab tsi.
thawj lub cev lub cev ntawm cov kua uas los rau hauv lub siab ntawm qhov hais txog lub xeev ntawm kev sib sau ua ke yog lub peev xwm hloov pauv thiab tuav ib qho ntim. Yog li, piv txwv li, yog tias peb tham txog daim ntawv ntawm cov kua tshuaj, ces nws yog feem ntau lees txais los txiav txim nws tsis tuaj. Txawm li cas los xij, qhov no tsis yog qhov teeb meem.
Raws li qhov kev txiav txim ntawm lub zog uas paub zoo ntawm lub ntiajteb txawj nqus, cov tee ntawm cov teeb meem raug qee qhov deformation, yog li lawv cov duab tawg thiab ua tsis tiav. Txawm li cas los xij, yog tias koj tso qhov poob rau hauv cov xwm txheej uas lub ntiajteb txawj nqus tsis ualos yog nruj heev, ces nws yuav siv lub pob zoo tagnrho. Yog li, muab lub luag haujlwm: "Npe cov khoom ntawm cov kua," tus neeg uas xav tias nws tus kheej paub zoo hauv physics yuav tsum hais qhov tseeb no.
Raws li qhov ntim, ntawm no peb yuav tsum nco ntsoov cov khoom dav dav ntawm cov pa roj thiab kua. Ob leeg muaj peev xwm tuav tau tag nrho cov ntim ntawm qhov chaw uas lawv nyob, txwv tsuas yog cov phab ntsa ntawm lub nkoj.
Viscosity
Lub cev lub cev ntawm cov kua muaj ntau yam. Tab sis ib qho ntawm lawv yog tshwj xeeb, xws li viscosity. Nws yog dab tsi thiab nws txhais li cas? Cov tsis tseem ceeb uas tus nqi xav tau yog nyob ntawm:
- tangential stress;
- txav nrawm gradient.
Qhov kev vam khom ntawm qhov qhia qhov tseem ceeb yog linear. Yog tias peb piav qhia hauv cov lus yooj yim, ces viscosity, zoo li ntim, yog cov khoom ntawm cov kua thiab cov pa uas muaj feem rau lawv thiab hais txog kev txav mus los tsis muaj kev txwv, tsis hais lub zog sab nraud ntawm lub zog. Qhov ntawd yog, yog tias dej ntws tawm ntawm lub nkoj, nws yuav ua li ntawd nyob rau hauv ib qho kev cuam tshuam (lub ntiajteb txawj nqus, kev sib txhuam, thiab lwm yam).
Qhov no txawv ntawm cov kua dej uas tsis yog-Newtonian, uas yog cov kua nplaum ntau dua thiab tuaj yeem tso cov qhov hauv qab los ua kom puv sijhawm.
qhov ntsuas no nyob ntawm dab tsi?
- Los ntawm qhov kub thiab txias. Nrog rau qhov kub thiab txias, viscosity ntawm qee cov kua dej nce, thaum lwm tus, ntawm qhov tsis sib xws,txo. Nws nyob ntawm qhov chaw tshwj xeeb thiab nws cov qauv tshuaj.
- Los ntawm siab. Kev nce ntxiv ua rau muaj qhov nce ntxiv hauv qhov ntsuas viscosity.
- Los ntawm cov tshuaj muaj pes tsawg leeg ntawm cov teeb meem. Viscosity hloov nyob rau hauv lub xub ntiag ntawm impurities thiab txawv teb chaws Cheebtsam nyob rau hauv ib tug qauv ntawm ib tug ntshiab tshuaj.
Heat peev
lo lus no yog hais txog lub peev xwm ntawm ib yam khoom los nqus cov cua sov kom nws tus kheej kub nce mus txog ib degree Celsius. Muaj kev sib txuas sib txawv rau qhov ntsuas no. Qee tus muaj ntau dua, lwm tus muaj peev xwm qis dua.
Yog li, piv txwv li, dej yog cov khoom siv hluav taws xob zoo heev, uas tso cai rau nws siv dav rau cov tshuab cua sov, ua noj thiab lwm yam kev xav tau. Feem ntau, qhov ntsuas kub muaj peev xwm yog nruj me ntsis rau txhua tus neeg ua kua.
Ntog nro
Ntau zaus, tau txais txoj haujlwm: "Npe cov khoom ntawm cov kua," lawv nco qab tam sim ntawd qhov nro. Tom qab tag nrho, cov menyuam yaus raug qhia rau nws ntawm cov lus qhia ntawm physics, chemistry thiab biology. Thiab txhua yam piav qhia qhov tseem ceeb no los ntawm nws tus kheej sab.
Lub ntsiab txhais ntawm qhov nro saum npoo yog cov hauv qab no: nws yog ib theem ciam teb. Ntawd yog, thaum lub sijhawm cov kua tau nyob hauv qee qhov ntim, nws ciam teb rau sab nraud nrog lub nruab nrab gaseous - huab cua, chav lossis lwm yam khoom. Yog li, kev sib cais theem tshwm sim ntawm qhov chaw sib cuag.
Tib lub sijhawm, cov molecules nyiam nyob ib puag ncig lawv tus kheej nrog ntau qhov ua tau thiab, yog li, txhuas, raws li nws tau,compressing cov kua tag nrho. Yog li ntawd, qhov saum npoo zoo li stretched. Tib yam khoom tseem tuaj yeem piav qhia cov duab kheej kheej ntawm cov kua dej hauv qhov tsis muaj lub ntiajteb txawj nqus. Tom qab tag nrho, nws yog daim ntawv no uas zoo tagnrho los ntawm qhov pom ntawm lub zog ntawm lub molecule. Piv txwv:
- xab npuas;
- dej poob hauv qhov hnyav.
Nyob zoo ib tsoom niam txiv kwv tij neej tsas sawv daws.
Qee cov kab tau yoog rau "taug kev" ntawm cov dej kom meej vim yog qhov nro. Piv txwv li: dej striders, waterfowl, some grubs.
xim
Muaj cov khoom sib xws ntawm cov kua thiab cov khoom khib nyiab. Ib tug ntawm lawv yog fluidity. Qhov txawv tag nrho yog tias rau yav dhau los nws yog unlimited. Dab tsi yog qhov tseem ceeb ntawm qhov ntsuas no?
Yog tias koj siv lub zog sab nraud rau lub cev ua kua, nws yuav faib ua ntu thiab cais lawv ntawm ib leeg, uas yog, nws yuav ntws. Nyob rau hauv cov ntaub ntawv no, txhua feem yuav rov sau tag nrho cov ntim ntawm lub nkoj. Rau cov khib nyiab, cov cuab yeej no raug txwv thiab nyob ntawm cov xwm txheej sab nraud.
Kev nyob ntawm cov khoom ntawm qhov kub thiab txias
Cov no suav nrog peb qhov tsis zoo uas qhia txog cov khoom peb tab tom txiav txim siab:
- overheat;
- txias;
- boiling.
Cov khoom ntawm cov kua dej ua kom sov thiab kub siab yog cuam tshuam ncaj qha rau qhov tseem ceeb ntawm qhov kub thiab txias (cov ntsiab lus), feem. Cov kua dej kub dhau yog cov kua uas tau kov yeej qhov pib ntawm qhov ntsuas kub tseem ceeb thaum raug kub, tab sis tsis tau pom cov tsos mob sab nraud ntawm qhov kub.
Supercooled, ntsig txog, hu uacov kua uas tau dhau qhov pib ntawm qhov tseem ceeb ntawm kev hloov mus rau lwm theem nyob rau hauv qhov kev cuam tshuam ntawm qhov kub thiab txias, tab sis tsis tau dhau los ua ib qho khoom.
Nyob rau hauv thawj thiab thib ob, muaj cov xwm txheej rau kev tshwm sim ntawm cov khoom zoo li no.
- Tsis muaj kev cuam tshuam rau lub cev (kev txav, kev vibration).
- ntsuas kub ib puag ncig, tsis muaj dhia sai sai.
Qhov tseeb nthuav yog tias yog tias koj pov ib yam khoom txawv teb chaws rau hauv cov kua dej uas muaj cua sov (piv txwv li, dej), nws yuav npau taws sai sai. Koj tuaj yeem tau txais nws los ntawm cua sov hauv qab hluav taws xob (hauv lub qhov cub microwave).
Kev sib koom nrog lwm theem ntawm teeb meem
Muaj ob txoj kev xaiv rau qhov ntsuas no.
- Kua - gas. Cov kab ke no yog qhov dav tshaj plaws, txij li lawv muaj nyob txhua qhov chaw hauv qhov xwm txheej. Tom qab tag nrho, cov evaporation ntawm dej yog ib feem ntawm lub ntuj voj voog. Nyob rau hauv cov ntaub ntawv no, lub resulting chav tshwm sim ib txhij nrog kua dej. Yog tias peb tham txog lub kaw lus kaw, ces evaporation tshwm sim nyob ntawd thiab. Nws tsuas yog tias chav ua kom saturated sai heev thiab tag nrho cov kab ke tag nrho los rau qhov sib npaug: kua - saturated steam.
- Kua - khoom. Tshwj xeeb tshaj yog nyob rau hauv xws li systems, ib tug ntxiv khoom yog pom tau hais tias - wettability. Hauv kev sib cuam tshuam ntawm cov dej thiab cov khoom, cov tom kawg tuaj yeem wetted tag nrho, ib nrab, lossis txawm tias cov dej tawm. Muaj cov tebchaw uas yaj hauv dej sai sai thiab siv sijhawm tsis kawg. Muaj cov uas tsis muaj peev xwm ntawm qhov no tag nrho (qee yam hlau, pob zeb diamond thiab lwm yam).
Feem ntau, kev qhuab qhia ntawm hydroaeromechanics yog koom nrog kev kawm txog kev sib cuam tshuam ntawm cov kua nrog cov tebchaw hauv lwm lub xeev ntawm kev sib sau.
Compressibility
Cov khoom tseem ceeb ntawm cov kua dej yuav ua tsis tiav yog tias peb tsis hais txog compressibility. Tau kawg, qhov ntsuas no yog qhov zoo dua rau cov tshuab roj. Txawm li cas los xij, cov uas peb tab tom txiav txim siab kuj tuaj yeem raug compressed raws li qee yam xwm txheej.
Qhov sib txawv tseem ceeb yog qhov ceev ntawm cov txheej txheem thiab nws qhov sib xws. Thaum cov roj tuaj yeem compressed sai thiab nyob rau hauv qis qis, cov kua yog compressed tsis sib npaug, ntev txaus thiab nyob rau hauv tshwj xeeb xaiv tej yam kev mob.
Evaporation thiab condensation ntawm cov kua
Cov no yog ob qho khoom ntxiv ntawm cov kua. Physics muab lawv cov lus piav qhia hauv qab no:
- Evaporation yog cov txheej txheem uas qhia txog kev hloov pauv ntawm cov tshuaj los ntawm cov kua hauv lub xeev ntawm kev sib sau mus rau lub xeev khov. Qhov no tshwm sim nyob rau hauv kev cuam tshuam ntawm thermal teebmeem ntawm lub system. Cov molecules pib txav mus thiab, hloov lawv cov iav siv lead ua, dhau mus rau hauv lub xeev gaseous. Cov txheej txheem tuaj yeem txuas ntxiv mus txog thaum tag nrho cov kua hloov mus rau vapor (rau qhib lub tshuab). Los yog kom txog thaum muaj kev sib npaug (rau cov nkoj kaw).
- Condensation yog txheej txheem tawm tsam rau ib qho qhia saum toj no. Ntawm no cov vapor nkag mus rau hauv cov kua molecules. Qhov no tshwm sim kom txog thaum muaj kev sib npaug lossis kev hloov pauv tiav. Cov pa tso tawm ntau cov khoom rau hauv cov kua ntau dua li nws ua rau nws.
Cov piv txwv ntawm ob txheej txheem no nyob rau hauv qhov xwm txheej yog cov evaporation ntawm dej los ntawm lub ntiaj teb dej hiav txwv, nws condensation nyob rau hauvhuab cua sab saud thiab tom qab ntawd poob tawm.
Mechanical properties of fluid
Cov khoom no yog kev kawm txog kev tshawb fawb xws li hydromechanics. Tshwj xeeb, nws seem, txoj kev xav ntawm cov kua thiab roj mechanics. Cov yam ntxwv tseem ceeb ntawm cov khoom siv hluav taws xob uas qhia txog lub xeev ntawm kev sib sau ntawm cov khoom muaj xws li:
- density;
- share;
- viscosity.
Raws li qhov ntom ntawm lub cev ua kua nkag siab txog nws qhov loj, uas muaj nyob rau hauv ib chav tsev ntawm ntim. Qhov ntsuas no sib txawv rau cov khoom sib txawv. Muaj twb tau suav thiab sim ntsuas cov ntaub ntawv ntawm qhov ntsuas no, uas tau nkag rau hauv cov rooj tshwj xeeb.
Kev nqus tshwj xeeb yog suav tias yog qhov hnyav ntawm ib chav ntim ntawm cov kua. Qhov ntsuas no yog nyob ntawm qhov kub thiab txias (raws li nws nce, nws qhov hnyav txo).
Vim li cas kawm txog cov khoom siv hluav taws xob ntawm cov kua? Qhov kev paub no tseem ceeb rau kev nkag siab txog cov txheej txheem tshwm sim hauv qhov xwm txheej, hauv tib neeg lub cev. Tsis tas li thaum tsim kev txhais tau tias, ntau yam khoom. Tom qab tag nrho, cov kua tshuaj yog ib qho ntawm cov ntaub ntawv sib sau ua ke tshaj plaws hauv peb lub ntiaj teb.
Non-Newtonian kua thiab lawv cov khoom
Cov khoom ntawm cov pa roj, kua, cov khoom khib nyiab yog cov khoom siv ntawm kev kawm physics, nrog rau qee yam kev qhuab qhia. Txawm li cas los xij, ntxiv rau cov tshuaj ua kua ib txwm muaj, kuj tseem hu ua non-Newtonian, uas kuj tau kawm los ntawm qhov kev tshawb fawb no. Lawv yog dab tsi thiab vim li cas lawv tau txaislub title yog dab tsi?
Yuav kom nkag siab tias cov tebchaw no yog dab tsi, ntawm no yog cov piv txwv ntawm tsev neeg feem ntau:
- "Slime" ua si los ntawm menyuam yaus;
- "cov pos hniav", los yog zom cov pos hniav rau tes;
- kev tsim kho xim;
- daws cov hmoov txhuv nplej siab hauv dej, thiab lwm yam.
Ntawd yog, cov no yog cov kua dej uas nws cov viscosity ua raws li qhov nrawm nrawm. Qhov cuam tshuam sai dua, qhov siab dua qhov viscosity index. Yog li ntawd, thaum cov pos hniav tsoo hauv pem teb nrog lub tshuab ntse, nws hloov mus rau hauv ib yam khoom uas muaj peev xwm tawg ua tej daim.
Yog tias koj tso nws ib leeg, tom qab ob peb feeb nws yuav kis mus rau hauv lub pas dej nplaum. Cov kua dej uas tsis yog-Newtonian yog cov khoom tshwj xeeb hauv cov ntsiab lus ntawm lawv cov khoom, uas tau siv tsis yog rau cov hom phiaj kev lag luam xwb, tab sis kuj yog rau kev coj noj coj ua thiab txhua hnub.
