Izinto Eziqinile Neziguquguqukayo Zoketshezi
Ama-fluid ayisihloko esithakazelisayo ku-physics, njengoba ehilela izakhiwo kanye nokuziphatha kwezinto ezingageleza, njengoketshezi namagesi. Ama-fluid statics kanye ne-fluid dynamics amagatsha amabili ayinhloko okutadisha uketshezi, ngalinye linezici zalo ezihlukile kanye nokusetshenziswa. Kulesi sihloko, sizobuyekeza izisekelo ze-fluid statics kanye ne-fluid dynamics theory, kanye nezinye izibonelo zomhlaba wangempela zezicelo zazo empilweni yansuku zonke.
Uketshezi Olungaguquki
Uketshezi olumile luwuketshezi oluphumule, okusho ukuthi alunawo umnyakazo. Ucwaningo lweziketshezi ezimile luvame ukubizwa ngokuthi yi-hydrostatics. Eminye imiqondo ebalulekile kuziketshezi ezimile ifaka phakathi ingcindezi ye-hydrostatic, isimiso sikaPascal, kanye nomthetho ka-Archimedes.
Ukucindezela Okungamanzi
Ingcindezi kuketshezi olunganyakazi amandla asebenza endaweni yobuso ngeyunithi futhi avame ukusebenza ngokulinganayo kuzo zonke izinhlangothi. Lokhu kucindezela kubangelwa isisindo soketshezi ngaphezu kwendawo yokubuka. I-hydrostatic pressure equation ivezwa kanje:
\[ P = P_0 + \rho gh \]
Kuphi:
– \( P \) ingcindezi ekujuleni \( h \).
– \( P_0 \) ingcindezi engaphezulu.
– \( \rho \) ukuminyana koketshezi.
– \( g \) ukusheshisa okubangelwa amandla adonsela phansi.
– \( h \) ukujula.
Isibonelo esilula yingcindezi umuntu obhukudayo ayizwayo njengoba ejula ngaphansi kwamanzi. Lapho umuntu obhukudayo ejula, kulapho ezwa khona ingcindezi enkulu ngenxa yesisindo samanzi angaphezu kwawo.
Isimiso sikaPascal
Isimiso sikaPascal sithi ushintsho ekucindezelweni noma kuphi oketshezini oluvalekile ludluliselwa ngokulinganayo kulo lonke uketshezi. Lesi simiso sinezinhlelo eziningi ezisebenzayo, njengasezinhlelweni ze-hydraulic. Isibonelo, ku-hydraulic jack, amandla amancane asetshenziswa ku-piston encane akhiqiza amandla amakhulu ku-piston enkulu.
Umthetho ka-Archimedes
Umthetho ka-Archimedes uthi noma iyiphi into ecwiliswe kancane noma ngokuphelele oketshezini izobhekana namandla okukhuphuka alingana nesisindo soketshezi olususwe yinto. La mandla okukhuphuka aziwa ngokuthi ukukhuphuka.
\[ F_b = \rho g V \]
Kuphi:
– \( F_b \) amandla okuphakamisa.
– \( \rho \) ukuminyana koketshezi.
– \( g \) ukusheshisa okubangelwa amandla adonsela phansi.
– \( V \) umthamo woketshezi olususiwe.
Isibonelo yilapho umkhumbi untanta phezu kwamanzi. Umkhumbi ungantanta ngoba isisindo samanzi owususayo silingana nesisindo somkhumbi ngokwawo, okukhiqiza amandla akhuphukayo.
Amandla Oketshezi
Ngaphandle kwezimo ezimile, uketshezi luvame ukuhamba noma ukugeleza. Ucwaningo lokuziphatha koketshezi oluhambayo lwaziwa ngokuthi yi-hydrodynamics. Eminye imiqondo ebalulekile ku-fluid dynamics ifaka phakathi i-continuity equation, i-Bernoulli equation, kanye nemithetho ye-Navier-Stokes.
Isibalo Sokuqhubeka
I-equation yokuqhubeka ithi ekugelezeni koketshezi okungacindezeleki, izinga lokugeleza kobuningi bokungena kumele lilingane nezinga lokugeleza kobuningi bokuphuma. Lesi sibalo singachazwa kanje:
\[ A_1 v_1 = A_2 v_2 \]
Kuphi:
– \( A_1 \) kanye \( A_2 \) yizindawo ezihlukaniswe ngamaphoyinti 1 no-2.
– \( v_1 \) kanye \( v_2 \) yijubane lokugeleza kwamaphuzu 1 no-2.
Isibonelo ipayipi lamanzi elinesiphetho esincane. Uma ipayipi licindezelwa ekugcineni, amanzi aphuma ngokushesha ngoba indawo enqamulayo ekugcineni kwepayipi incane.
Isibalo sikaBernoulli
Isibalo sikaBernoulli sithi ekugelezeni koketshezi okungacindezeleki, okungenamshuko, inani lamandla omshini (ingcindezi, amandla e-kinetic, kanye namandla angase abe khona) ngevolumu ngayinye lihlala linjalo. Lesi sibalo sibhalwe kanje:
\[ P + \frac{1}{2} \rho v^2 + \rho gh = \text{constant} \]
Kuphi:
– \( P \) ukucindezela koketshezi.
– \( \rho \) ukuminyana koketshezi.
– \( v \) ijubane lokugeleza koketshezi.
– \( g \) ukusheshisa okubangelwa amandla adonsela phansi.
– \( h \) ukuphakama ngaphezu kwephuzu lokubhekisela.
Isibonelo sangempela se-equation kaBernoulli iphiko lendiza. Ukuma kwephiko lendiza kwaklanywa ngendlela yokuthi umoya ogeleza phezu kwephiko ube nesivinini esiphezulu kunomoya ongaphansi kwephiko. Lokhu kuholela ekucindezelekeni okuphansi ngaphezu kwephiko kunangaphansi, okudala ukuphakama okuphezulu okuvumela indiza ukuthi indize.
Umthetho weNavier-Stokes
Imithetho ye-Navier-Stokes iyiqoqo lezibalo ezichaza ukunyakaza koketshezi. Lezi zibalo ziyinkimbinkimbi futhi zihilela ukuhlaziywa kwezibalo okuyinkimbinkimbi, kodwa ziyisisekelo sokuqonda ukuguquguquka koketshezi. Le mithetho ithatha isimo:
\[ \rho \left( \frac{\partial \mathbf{v}}{\partial t} + \mathbf{v} \cdot \nabla \mathbf{v} \right) = -\nabla P + \mu \nabla^2 \mathbf{v} + \mathbf{f} \]
Kuphi:
– \( \rho \) ukuminyana koketshezi.
– \( \mathbf{v} \) ijubane lokugeleza koketshezi.
– \( \mu \) yi-viscosity enamandla yoketshezi.
– \( \mathbf{f} \) amandla angaphandle ngevolumu yeyunithi ngayinye.
Lezi zibalo ziyisisekelo sezinhlelo zokusebenza eziningi zobunjiniyela, okuhlanganisa ukulingisa ukugeleza komoya ezimotweni, ukugeleza kwegazi ezitsheni, kanye nokusatshalaliswa kwamafutha emapayipini.
Izicelo Zoketshezi Ezingaguquki Nezishintshayo
Imibono ye-fluid statics kanye ne-dynamics isetshenziswa emikhakheni eyahlukene njengobunjiniyela bezokwakha, ubunjiniyela bemishini, ezokwelapha, i-meteorology, kanye nemvelo. Ezinye izinhlelo zokusebenza zomhlaba wangempela zifaka:
1. Umklamo Wedamu Nedamu: Ukusebenzisa izimiso zokucindezela kwe-hydrostatic kanye nomthetho ka-Archimedes ukuqinisekisa ukuzinza kwezakhiwo ngaphansi kokucindezela kwamanzi.
2. Uhlelo lwe-Hydraulic: Ukusetshenziswa komgomo kaPascal kumabhuleki e-hydraulic ezimoto nemishini yokwakha.
3. Izindiza: Ukusetshenziswa kwesibalo sikaBernoulli ekwakhiweni kwamaphiko ezindiza ukuze kukhiqizwe ukuphakamisa.
4. Ukumodela Kwesimo Sezulu: Ukusebenzisa imithetho ye-Navier-Stokes kusiza ukubikezela amaphethini omoya kanye nezinye izimo zezulu.
5. Ezokwelapha: Ukuhlaziywa kokugeleza kwegazi kusetshenziswa izimiso zokuguquguquka koketshezi ukuze kutholakale isifo senhliziyo nemithambo yegazi.
Isiphetho
Ukuqonda izisekelo ze-fluid statics kanye ne-dynamics kubalulekile ezinhlobonhlobo zezicelo zesayensi nezobunjiniyela. Ngokuqonda izakhiwo kanye nokuziphatha kwe-fluids, ososayensi nonjiniyela bangaklama futhi bathuthukise ubuchwepheshe obusebenza kahle futhi obuphephile, kusukela ezindizeni kuya kumadivayisi ezokwelapha. I-Fluid statics inikeza ukuqonda ukuthi i-fluid iziphatha kanjani lapho iphumule, kuyilapho i-fluid dynamics yembula ubunzima be-fluid behavior ekugelezeni. Zombili ziyizinsika ezibalulekile zensimu ye-physics ehlala ishintsha.
