Laminar Flow vs Turbulent Flow
Fluid Dynamics yog ib feem tseem ceeb ntawm classical physics, thiab cov ntawv thov khiav los ntawm dej rau tib neeg lub cev. Nws muaj kev koom tes hauv engineering tseem ceeb hauv kev lag luam aerospace, marine, irrigation, hydraulic thiab ntau lwm yam kev qhuab qhia.
Cov kua dej sib txawv ntawm ib lub xeev mus rau lwm qhov, thiab kom yooj yim ntawm kev txheeb xyuas, cov dej ntws tau muab faib ua ntau hom kev tswj hwm uas cov kua dej xws li kev tshaj tawm, siab, ceev, thiab viscosity ua rau txhua tus tswj hwm. Turbulent thiab Laminar ntws yog ob chav kawm tseem ceeb ntawm kev khiav dej num.
Laminar Flow yog dab tsi?
Thaum cov kua dej ntws tsis sib tshuam ntawm txoj kev ntawm ib leeg thiab qhov nrawm ntawm cov khoom yog ib txwm tangential mus rau txoj kev ntawm cov khoom, cov dej ntws tau hais kom ua kom yooj yim. Thaum cov streamline ntws tshwm sim, cov khaubncaws sab nraud povtseg ntawm cov kua dej zoo li zawv zawg ntawm cov khoom uas nyob ib sab yam tsis muaj kev cuam tshuam kev txav ntawm lwm tus, thiab qhov no tshwm sim hauv cov khaubncaws sab nraud povtseg lossis laminas ntawm cov kua dej ntws. Xws li qhov ntws yog hu ua Laminar flow. Laminar flow los yog streamline flow tshwm sim thaum cov dej tshaj tawm kuj qis.
Nyob rau hauv laminar ntws, txheej nyob rau hauv kev sib cuag nrog ib tug nyob ruaj ruaj nto muaj xoom tshaj tawm thiab, nyob rau hauv cov kev taw qhia perpendicular rau saum npoo, qhov tshaj tawm ntawm cov khaubncaws sab nraud povtseg nyhav nce. Tsis tas li ntawd, qhov nrawm, siab, ceev, thiab lwm yam dej dynamic zog tseem tsis hloov ntawm txhua qhov chaw hauv qhov chaw ntws.
Tus lej Reynolds yog qhov qhia tau tias cov kua dej zoo npaum li cas tuaj yeem nkag mus rau laminar ntws. Thaum Reynolds tus naj npawb tsawg, qhov ntws zoo li laminar, thiab cov viscous rog yog qhov tseem ceeb ntawm kev sib cuam tshuam ntawm cov khaubncaws sab nraud povtseg. Thaum Reynolds tus naj npawb siab, cov dej ntws yuav ua rau muaj kev kub ntxhov, thiab inertial rog yog qhov tseem ceeb ntawm kev sib cuam tshuam ntawm cov khaubncaws sab nraud povtseg.
Turbulent Flow yog dab tsi?
Thaum cov kua dej hauv cov dej ntws sib txawv nrawm nrog lub sijhawm, piv txwv li thaum cov kev hloov pauv hauv qhov nrawm, siab, ceev, thiab lwm yam dej ntws qhia kev hloov pauv thiab tsis txaus ntseeg, qhov ntws tau paub tias yog qhov dej ntws tawm.
Cov kua dej ntws tawm hauv cov yeeb nkab cylindrical uas muaj qhov ntev ntev, tseem hu ua Poiseuille ntws, yuav muaj turbulence nyob rau hauv cov ndlwg thaum tus xov tooj Reynolds mus txog tus lej tseem ceeb 2040. Txawm li cas los xij, feem ntau, qhov ntws yuav tsis meej meej. yuav turbulent thaum tus lej Reynolds ntau dua 10000.
Ib qho dej ntws ntws tawm yog yam ntxwv los ntawm nws qhov xwm txheej tsis sib xws, diffusivity, thiab vorticity. Cov dej ntws muaj eddies, hla tam sim no thiab vortices.
Qhov txawv ntawm Laminar thiab Turbulent Flow yog dab tsi?
• Nyob rau hauv laminar ntws, qhov ntws tshwm sim ntawm qhov qis qis thiab qis Reynolds tus naj npawb, thaum turbulence flow tshwm sim ntawm qhov nrawm thiab siab Reynolds tus lej.
• Hauv Laminar ntws, txoj hauv kev ntawm cov kab kua dej yog qhov tsis tu ncua thiab ua kom yooj yim uas tsis muaj kev cuam tshuam sab nraud ntawm cov kua dej thiab cov kua dej ntws hauv txheej. Nyob rau hauv turbulent flow, tus qauv ntws tsis xwm yeem thiab chaotic, qhov twg vortices, eddies, thiab hla tam sim no tshwm sim.
• Nyob rau hauv laminar ntws, cov kua dej ntawm ib qho chaw hauv qhov chaw nyob tas li nrog lub sij hawm thaum, nyob rau hauv turbulent flow, cov kua dej ntawm ib tug taw tes yog stochastic.
