Ua tsaug rau koj tuaj xyuas Nature.com.Qhov browser version koj siv tau txwv kev txhawb nqa rau CSS.Rau qhov kev paub zoo tshaj plaws, peb xav kom koj siv qhov browser tshiab (lossis kaw qhov kev sib raug zoo hauv Internet Explorer).
Cov kev sim tau ua nyob rau hauv ib lub voj voos uas thaiv los ntawm cov kab hla ntawm plaub inclined cylindrical rods.Qhov siab ntawm qhov nruab nrab pas nrig nto thiab lub siab poob ntawm cov channel raug ntsuas los ntawm kev sib txawv ntawm tus pas nrig inclination lub kaum sab xis. Peb qhov sib txawv ntawm txoj kab uas hla pas nrig sib dhos tau kuaj.Cov kev ntsuas ntsuas tau soj ntsuam siv lub hauv paus ntsiab lus ntawm kev txuag ntawm qhov ntsuas qhov ntsuas qhov tsis muaj qhov ntsuas thiab qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv. d uas cuam tshuam lub siab ntawm qhov chaw tseem ceeb ntawm lub kaw lus rau tus yam ntxwv qhov ntev ntawm tus pas nrig.Qhov kev ywj pheej txoj cai yog pom los tuav rau feem ntau Euler tooj characterizing siab ntawm qhov chaw sib txawv, piv txwv li yog tias lub siab yog dimensionless siv qhov projection ntawm inlet tshaj tawm ib txwm rau tus pas nrig, lub teeb yog ywj siab ntawm lub kaum sab xis.Qhov tshwm sim semi-empirical correlation tuaj yeem siv rau Tsim cov hydraulics zoo sib xws.
Ntau cov khoom siv hluav taws xob thiab cov khoom siv hluav taws xob hloov pauv muaj xws li cov txheej txheem, cov channel lossis cov hlwb los ntawm cov kua dej nkag mus rau hauv ntau dua lossis tsawg dua cov txheej txheem sab hauv xws li rods, buffers, inserts, thiab lwm yam. Tsis ntev los no, tau muaj kev txaus siab rau kev nkag siab zoo dua ntawm cov txheej txheem txuas nrog lub siab faib thiab lub zog ntawm cov khoom siv sab hauv mus rau tag nrho cov siab poob ntawm lub module.Ntawm lwm yam, qhov kev txaus siab ntawm cov khoom siv tshiab no tau ua tiav. ulations, thiab nce miniaturization ntawm cov cuab yeej. Tsis ntev los no kev sim kev tshawb fawb ntawm siab nyob rau hauv tis thiab poob muaj xws li raws roughened los ntawm ntau yam zoo li tus tav 1, electrochemical reactor hlwb 2, capillary constriction 3 thiab lattice thav duab cov ntaub ntawv 4.
Cov txheej txheem sab hauv feem ntau yog sib cav cylindrical rods los ntawm chav tsev modules, yog bundled los yog cais.In tshav kub exchangers, no configuration yog raug rau ntawm lub plhaub sab.Shell sab siab poob yog muaj feem xyuam rau cov tsim ntawm tshav kub exchangers xws li chav generators, condensers thiab evaporators.5 pom reattachment thiab co-detachment flow states nyob rau hauv ib tug tandem configuration ntawm rods.Liu li al.6 ntsuas lub siab poob nyob rau hauv rectangular raws nrog built-in ob U-shaped raj bundles nrog txawv inclination ces kaum thiab calibrated ib tug lej qauv simulating pas nrig bundles nrog porous xov xwm.
Raws li qhov xav tau, muaj ntau yam kev teeb tsa uas cuam tshuam rau kev ua haujlwm hydraulic ntawm lub tog raj kheej lub txhab nyiaj: hom kev npaj (piv txwv li, staggered lossis in-line), cov txheeb ze qhov ntev (xws li, suab, txoj kab uas hla, qhov ntev), thiab lub kaum sab xis inclination, thiab lwm yam. Ntau tus kws sau ntawv tau tsom mus rau kev nrhiav qhov tsis muaj qhov ntsuas los qhia cov qauv tsim los ntes cov teebmeem ntawm cov duab geometric tsis ntev los no.7 tau npaj ib qho qauv zoo porosity siv qhov ntev ntawm chav tsev cell raws li kev tswj tsis tau, siv tandem thiab staggered arrays thiab Reynolds tus lej ntawm 103 thiab 104.Snarski8 tau kawm yuav ua li cas lub hwj chim spectrum, los ntawm accelerometers thiab hydrophones txuas rau lub tog raj kheej nyob rau hauv ib lub qhov dej.9 kawm txog phab ntsa siab faib nyob ib ncig ntawm ib tug cylindrical pas nrig hauv yaw airflow.Mityakov li al.10 plotted lub nrawm teb tom qab yawed lub tog raj kheej siv lub tso suab PIV.Alam li al.11 tau ua ib qho kev kawm tiav ntawm tandem cylinders, tsom rau qhov cuam tshuam ntawm Reynolds tus naj npawb thiab geometric piv ntawm vortex shedding.Lawv muaj peev xwm txheeb xyuas tsib lub xeev, xws li kev ntsuas qhov ntsuas, sib cuam tshuam, tsis muaj kev ntsuas, subharmonic locking thiab shear txheej reattachment xeev. lub tog raj kheej.
Feem ntau, kev ua haujlwm hydraulic ntawm ib lub xovtooj ntawm tes yuav tsum nyob ntawm qhov kev teeb tsa thiab geometry ntawm cov qauv sab hauv, feem ntau suav nrog kev sib raug zoo ntawm cov kev ntsuas kev ntsuas tshwj xeeb.In ntau cov khoom siv uas muaj cov khoom siv raws sij hawm, cov qauv ntws tau rov ua dua nyob rau hauv txhua lub xovtooj, thiab yog li, cov ntaub ntawv ntsig txog cov neeg sawv cev ntawm tes tuaj yeem siv los qhia txog tag nrho cov qauv hydraulic ntawm cov qauv ntawm cov qauv. Feem ntau tuaj yeem raug txo qis.Ib qho piv txwv yog qhov sib npaug ntawm qhov sib npaug ntawm lub orifice phaj 15.Nyob rau hauv cov ntaub ntawv tshwj xeeb ntawm inclined rods, txawm nyob rau hauv confined los yog qhib txaus, ib tug nthuav cov ntsiab lus feem ntau hais nyob rau hauv cov ntaub ntawv thiab siv los ntawm designers yog lub tseem ceeb hydraulic magnitude (piv txwv li, siab poob, quab yuam, vortex shedding zaus, thiab lwm yam). Feem ntau hu ua txoj cai ywj pheej thiab xav tias cov dej ntws tawm tau tsav feem ntau los ntawm cov dej ntws ib txwm muaj thiab qhov cuam tshuam ntawm axial tivthaiv raws li lub tog raj kheej axis yog negligible.Txawm hais tias tsis muaj kev pom zoo hauv cov ntaub ntawv ntawm qhov siv tau ntau yam ntawm qhov kev ntsuas no, ntau zaus nws muab cov txiaj ntsig zoo ntawm cov kev tshawb fawb tsis muaj tseeb. ity ntawm txoj cai ywj pheej suav nrog vortex-induced vibration16 thiab ib-theem thiab ob-theem nruab nrab drag417.
Hauv kev ua haujlwm tam sim no, cov txiaj ntsig ntawm kev tshawb fawb ntawm lub siab sab hauv thiab kev poob siab hauv ib channel nrog ib txoj kab transverse ntawm plaub inclined cylindrical rods tau nthuav tawm. Ntsuas peb lub pas nrig sib dhos nrog cov kab sib txawv, hloov lub kaum sab xis ntawm inclination.Lub hom phiaj tag nrho yog los tshawb xyuas cov txheej txheem uas lub siab faib rau ntawm tus pas nrig nto muaj feem xyuam rau tag nrho cov siab poob rau hauv cov channel.Experimental cov ntaub ntawv ntawm kev siv cov ntsiab lus ntawm lub sijhawm. los ntsuas qhov siv tau ntawm txoj cai ywj pheej.Thaum kawg, dimensionless semi-empirical correlations yog generated uas tuaj yeem siv los tsim cov khoom siv hydraulic zoo sib xws.
Cov kev sim teeb tsa muaj xws li ib qho kev ntsuam xyuas cov duab plaub uas tau txais cov cua ntws los ntawm cov kiv cua axial.Cov seem xeem muaj ib chav tsev uas muaj ob qho tib si hauv nruab nrab rods thiab ob tug ib nrab-rods embedded nyob rau hauv lub channel phab ntsa, raws li qhia nyob rau hauv daim duab 1e, tag nrho cov tib txoj kab uas hla.Figures 1a–e qhia cov ncauj lus kom ntxaws geometry thiab qhov ntev ntawm txhua qhov teeb tsa.
ib ntu Inlet (ntev hauv mm).Tsim b siv Openscad 2021.01, openscad.org.Main xeem seem (ntev hauv mm).Created nrog Openscad 2021.01, openscad.org c Hla-sectional saib ntawm lub ntsiab xeem seem (ntev hauv mm).Created siv Openscad 2021.d seem mm).Tsim nrog Openscad 2021.01, tawg pom ntawm seem kev xeem ntawm openscad.org e.Created nrog Openscad 2021.01, openscad.org.
Peb cov rods ntawm txawv diameters raug kuaj.Table 1 teev cov geometrical yam ntxwv ntawm txhua rooj plaub.Cov rods yog mounted rau ib tug protractor kom lawv lub kaum sab xis txheeb ze rau qhov khiav kev taw qhia yuav txawv ntawm 90 ° thiab 30 ° (Daim duab 1b thiab 3).Tag nrho cov rods yog ua los ntawm stainless hlau thiab lawv yog nruab nrab ntawm ob txoj hauj lwm nyob rau sab nraud gap. .
Lub inlet ntws tus nqi ntawm cov seem xeem tau ntsuas los ntawm ib tug calibrated venturi, raws li qhia nyob rau hauv daim duab 2, thiab soj ntsuam siv ib tug DP Cell Honeywell SCX.Cov kua dej kub ntawm qhov hluav taws xob ntawm lub xeem seem tau ntsuas nrog ib tug PT100 tus pas ntsuas kub thiab tswj ntawm 45 ± 1 ° C.Rau kom paub meej tias ib tug planar tshaj tawm tis turbulence ntawm peb cov dej nyob rau hauv lub screen quab yuam los ntawm kev ntsuam xyuas. s.A qhov kev ncua deb ntawm kwv yees li 4 hydraulic diameters tau siv nruab nrab ntawm lub vijtsam kawg thiab pas nrig, thiab qhov ntev ntawm qhov hluav taws xob yog 11 hydraulic diameters.
Schematic daim duab ntawm Venturi raj siv los ntsuas qhov inlet khiav tshaj tawm (ntev hauv millimeters).Tsim nrog Openscad 2021.01, openscad.org.
Saib xyuas lub siab ntawm ib qho ntawm lub ntsej muag ntawm tus pas nrig hauv nruab nrab los ntawm kev siv 0.5 hli siab kais ntawm nruab nrab ntawm lub dav hlau ntawm qhov kev xeem seem.Cov kais dej txoj kab uas hla sib haum mus rau 5 ° angular ncua;Yog li ntawd qhov tseeb ntawm lub kaum sab xis yog kwv yees li 2 ° .Lub pas nrig saib tuaj yeem tig tau ntawm nws cov axis, raws li pom hauv daim duab 3.Qhov sib txawv ntawm tus pas nrig nto siab thiab lub siab ntawm qhov nkag mus rau qhov kev xeem yog ntsuas nrog qhov sib txawv DP Cell Honeywell SCX series.Qhov sib txawv ntawm qhov ntsuas no yog ntsuas rau txhua qhov kev teeb tsa bar, qhov sib txawv ntawm lub kaum sab xis \ taazimation, qhov sib txawv ntawm lub kaum sab xis ntawm lub kaum sab xis ntawm lub kaum sab xis. ).
Flow settings.Channel phab ntsa yog pom nyob rau hauv grey.Qhov ntws ntws los ntawm sab laug mus rau sab xis thiab yog thaiv los ntawm tus pas nrig.Nco ntsoov tias saib "A" yog perpendicular mus rau tus pas nrig axis.Cov pas nrig sab nraud yog ib nrab kos rau hauv cov phab ntsa sab nraud.A protractor yog siv los ntsuas lub kaum sab xis ntawm inclination \(\alpha \).Created.2.0.
Lub hom phiaj ntawm qhov kev sim yog ntsuas thiab txhais lub siab poob ntawm cov channel inlets thiab lub siab ntawm qhov chaw ntawm lub pas nrig, \(\theta\) thiab \(\alpha\) rau txawv azimuths thiab dips.Rau cov ntsiab lus, qhov sib txawv siab yuav tsum tau hais nyob rau hauv dimensionless daim ntawv raws li Euler tus naj npawb:
qhov twg \(\rho \) yog cov kua ntom ntom, \({u}_{i}\) yog qhov nruab nrab inlet tshaj tawm, \({p}_{i}\) yog lub siab inlet, thiab \({p }_{w}\) yog lub siab ntawm ib qho taw tes rau ntawm phab ntsa pas nrig.Qhov inlet tshaj tawm yog tsau nyob rau hauv peb qhov sib txawv ntawm qhov sib txawv ntawm qhov kev txiav txim los ntawm qhov qhib rau 6 m. Raws li cov channel Reynolds tus naj npawb, \(Re\equiv {u}_{i}H/\nu \) (qhov twg \(H\) yog qhov siab ntawm channel, thiab \(\nu \) yog kinematic viscosity) ntawm 40,000 thiab 67,000.The rod Reynolds tus naj npawb (\(\nu \) yog kinematic viscosity) nruab nrab ntawm 40,000 thiab 67,000.The rod Reynolds tus naj npawb (\(\nu \) \(\(\nu \)) ntawm 40,000 thiab 67,000. 500.Qhov turbulence siv kwv yees los ntawm tus txheeb ze tus qauv sib txawv ntawm cov teeb liab sau tseg hauv venturi yog 5% ntawm qhov nruab nrab.
Daim duab 4 qhia qhov sib txheeb ntawm \({Eu}_{w}\) nrog lub azimuth lub kaum sab xis \(\theta \), parameterized los ntawm peb lub kaum sab xis, \(\alpha \) = 30 °, 50 ° thiab 70 ° .Qhov kev ntsuas tau muab faib ua peb daim duab raws li txoj kab uas hla ntawm tus pas nrig. θ ua raws li ib txwm muaj ntawm phab ntsa siab nyob ib ncig ntawm ib ncig ntawm ib ncig ntawm lub voj voog ncig.Ntawm cov kaum sab xis ntws, piv txwv li, θ los ntawm 0 txog 90 °, lub pas nrig phab ntsa siab txo qis, nce mus txog qhov tsawg kawg nkaus ntawm 90 °, uas sib haum rau qhov sib txawv ntawm cov pas nrig uas qhov tshaj tawm yog loj tshaj plaws vim yog qhov kev txwv ntawm qhov chaw θ 10 ° rov qab los ntawm qhov kev txwv ntawm 0. °, tom qab ntawd lub siab tseem tsis sib xws vim qhov kev sib cais ntawm sab nraub qaum txheej ntawm lub pas nrig phab ntsa.Nco ntsoov tias tsis muaj kev hloov pauv ntawm lub kaum sab xis ntawm qhov siab kawg nkaus, uas qhia tau tias muaj kev cuam tshuam los ntawm cov txheej shear uas nyob ib sab, xws li cov teebmeem Coanda, yog qhov thib ob.
Variation ntawm Euler tus naj npawb ntawm phab ntsa nyob ib ncig ntawm tus pas nrig rau sib txawv inclination ces kaum thiab pas nrig diameters.Created nrog Gnuplot 5.4, www.gnuplot.info.
Hauv qab no, peb txheeb xyuas cov txiaj ntsig raws li qhov kev xav tias tus lej Euler tuaj yeem kwv yees los ntawm geometric tsis, piv txwv li qhov ntev ntawm qhov sib piv \(d / g\) thiab \(d / H\) (qhov twg \(H\) yog qhov siab channel) thiab inclination \(\alpha \). perpendicular mus rau tus pas nrig axis, \({u}_{n}={u}_{i}\mathrm {sin} \alpha \) .Qhov no qee zaum hu ua lub hauv paus ntsiab lus ntawm kev ywj pheej.Ib lub hom phiaj ntawm kev tshuaj xyuas hauv qab no yog los tshuaj xyuas seb lub hauv paus ntsiab lus no puas siv tau rau peb cov ntaub ntawv, qhov twg ntws thiab ob qho tib si raug kaw hauv cov kab kaw.
Cia peb xav txog lub siab ntsuas ntawm pem hauv ntej ntawm tus pas nrig nruab nrab, piv txwv li θ = 0.Raws li Bernoulli qhov sib npaug, lub siab ntawm txoj hauj lwm no\({p}_{o}\) txaus siab:
qhov twg \({u}_{o}\) yog cov dej tshaj tawm nyob ze ntawm phab ntsa pas nrig ntawm θ = 0, thiab peb xav tias kuj me me irreversible losses.Nco ntsoov tias lub zog dynamic siab yog ywj siab nyob rau hauv lub kinetic zog lub sij hawm.Yog \({u}_{o}\) yog khoob (xws li stagnant mob), tus Euler cov zauv yuav tsum tau nyob rau hauv 0. \) qhov tshwm sim \({Eu}_{w}\) yog ze rau tab sis tsis raws nraim qhov sib npaug ntawm tus nqi no, tshwj xeeb tshaj yog rau cov kaum sab xis loj dua.Qhov no qhia tias qhov nrawm ntawm tus pas nrig nto tsis ploj mus ntawm \(\theta = 0\), uas tej zaum yuav raug suppressed los ntawm upward deflection ntawm cov kab tam sim no tsim los ntawm tus pas nrig qaij.Vim tias cov dej ntws mus rau hauv qab, qhov kev ntsuam xyuas yuav tsum tau nce ntxiv. axial tshaj tawm nyob rau hauv qab thiab txo qhov tshaj tawm ntawm sab saum toj.Piv txwv tias qhov loj ntawm qhov deflection saum toj no yog qhov projection ntawm inlet tshaj tawm ntawm lub ncej (xws li \({u}_{i}\mathrm{cos}\alpha \)), qhov sib thooj Euler tus lej tshwm sim yog:
Daim duab 5 piv cov kab zauv.(3) Nws qhia tau hais tias qhov kev pom zoo zoo nrog cov ntaub ntawv kev sim sib thooj.Qhov sib txawv ntawm qhov sib txawv yog 25%, thiab qib kev ntseeg siab yog 95%. xeem ntu, \({p}_{e}\), Kuj ua raws li qhov sib piv rau \({\mathrm{sin}}^{2}\alpha \) .Nyob rau hauv ob qho tib si, qhov coefficient nyob ntawm tus pas nrig txoj kab uas hla, uas yog tsim nyog txij li thaum kawg txiav txim siab qhov chaw hindered.Qhov no feature zoo ib yam li lub siab poob ntawm ib tug orifice phaj, qhov twg qhov ntws ntawm qhov chaw los yog ib feem ntawm qhov chaw ua si. qhov sib txawv ntawm cov pas nrig.Qhov no, lub siab poob qis heev ntawm lub throttling thiab ib nrab rov qab los thaum nws nthuav rov qab.Xav txog qhov kev txwv raws li qhov thaiv ntawm cov pas nrig perpendicular, lub siab poob ntawm lub hauv ntej thiab nram qab ntawm tus pas nrig tuaj yeem sau tau raws li 18:
qhov twg \({c}_{d}\) yog ib tug luag coefficient piav qhia txog ib nrab siab rov qab ntawm θ = 90 ° thiab θ = 180 °, thiab \({A}_{m}\) thiab \ ({A}_{f}\) yog qhov tsawg kawg nkaus pub dawb hla ntu ntawm ib chav ntev perpendicular rau tus pas nrig {{g\}, thiab nws txoj kev sib raug zoo rau }_{{m}\} \right)/g\).Cov lej Euler sib raug yog:
Phab ntsa Euler tus naj npawb ntawm \(\theta = 0\) raws li kev ua haujlwm ntawm dip.This nkhaus sib raug rau qhov sib npaug.(3).Created nrog Gnuplot 5.4, www.gnuplot.info.
Phab ntsa Euler tus lej hloov pauv, hauv \(\theta = 18{0}^{o}\) (tag nrho kos npe) thiab tawm ( kos npe tsis muaj) nrog dip.Cov kab nkhaus no sib haum rau txoj cai ntawm kev ywj pheej, piv txwv li \(Eu\propto {\mathrm{sin}}^{2}\alpha \).Created with Gnuplot. 5.
Daim duab 7 qhia qhov kev vam khom ntawm \({Eu}_{0-180}/{\mathrm{sin}}^{2}\alpha \) ntawm \(d/g\), uas qhia qhov zoo sib xws.(5).Qhov tau txais cov coefficient yog \({c}_{d}=1.28\pm 0.02\) nrog ib qho kev ntseeg siab ntawm qhov 6 thiab tag nrho cov kev ntsuam xyuas. seem ua raws li cov qauv zoo sib xws, tab sis nrog cov coefficients sib txawv uas coj mus rau hauv tus account lub siab rov qab nyob rau hauv qhov chaw rov qab ntawm lub bar thiab qhov hluav taws xob ntawm cov channel.Qhov sib txuas coefficient yog \({c}_{d}=1.00\pm 0.05\) nrog kev ntseeg siab ntawm 67%.
Tus cab coefficient muaj feem xyuam rau \(d/g\) siab poob rau pem hauv ntej thiab tom qab ntawm tus pas nrig\(\left({Eu}_{0-180}\right)\) thiab tag nrho cov siab poob nruab nrab ntawm lub channel inlet thiab qhov hluav taws xob.Qhov grey cheeb tsam yog 67% kev ntseeg siab band rau correlation.Created nrog Gnuplot 5.4., www.gnup.
Qhov tsawg kawg nkaus siab \({p}_{90}\) ntawm tus pas nrig nto ntawm θ = 90 ° yuav tsum tau tshwj xeeb tuav.Raws li Bernoulli txoj kev sib npaug, raws li cov kab tam sim no los ntawm qhov sib txawv ntawm cov tuav, lub siab nyob rau hauv qhov chaw \({p}_{g}\) thiab lub tshaj tawm \({u}_{g}\) nyob rau hauv cov nram qab no cov ntsiab lus ntawm cov nyiaj npib nyob rau hauv nruab nrab ntawm qhov sib npaug ntawm cov nyiaj npib:
Lub siab \({p}_{g}\) tuaj yeem cuam tshuam rau tus pas nrig nto siab ntawm θ = 90 ° los ntawm kev sib koom ua ke ntawm qhov sib txawv ntawm qhov sib txawv uas sib cais cov pas nrig nruab nrab ntawm nruab nrab thiab phab ntsa (saib daim duab 8).Qhov sib npaug ntawm lub zog muab 19:
qhov twg \(y\) yog qhov sib koom ua ke ib txwm rau tus pas nrig nto los ntawm qhov chaw nruab nrab ntawm qhov sib txawv ntawm lub hauv paus rods, thiab \(K\) yog curvature ntawm txoj kab tam sim no ntawm txoj hauj lwm \(y\).Rau qhov kev ntsuam xyuas ntawm lub siab ntawm tus pas nrig nto, peb xav tias \({u}_{g}\) yog uniform thiab \( pt ions . Nyob rau ntawm phab ntsa pas nrig, qhov curvature yog txiav txim los ntawm lub ellipse seem ntawm tus pas nrig ntawm lub kaum sab xis \(\alpha \), i.e. \(K\left(g/2\right)=\left(2/d\right){\ mathrm{sin} }^{2}\alpha \) (saib \alpha \) (saib daim duab 8).Thenature of the streaming regarding the stream. , qhov curvature ntawm universal coordinate \(y\) yog muab los ntawm:
Feature cross-sectional saib, pem hauv ntej (sab laug) thiab saum toj no (hauv qab).Tsim nrog Microsoft Word 2019,
Ntawm qhov tod tes, los ntawm kev txuag ntawm huab hwm coj, qhov nruab nrab tshaj tawm nyob rau hauv ib lub dav hlau perpendicular rau qhov ntws ntawm qhov ntsuas qhov chaw \(\langle {u}_{g}\rangle \) muaj feem xyuam rau lub inlet tshaj tawm:
qhov twg \({A}_{i}\) yog qhov chaw hla ntu ntawm cov channel inlet thiab \({A}_{g}\) yog qhov chaw hla hla ntawm qhov chaw ntsuas (saib daim duab 8) raws li :
Nco ntsoov tias \({u}_{g}\) tsis sib npaug rau \(\langle {u}_{g}\rangle \).Qhov tseeb, daim duab 9 qhia txog qhov sib piv ceev \({u}_{g}/\langle {u}_{g}\rangle \), xam los ntawm qhov sib npaug.(10)–(14), plotted raws li qhov sib piv). ximated los ntawm ib tug thib ob-order polynomial:
Qhov ratio ntawm qhov siab tshaj plaws \({u}_{g}\) thiab nruab nrab\(\langle {u}_{g}\rangle \) tshaj tawm ntawm lub channel chaw hla ntu\.\) Cov khoom thiab dashed nkhaus sib raug rau qhov sib npaug.(5) thiab qhov sib txawv ntawm qhov sib thooj ntawm cov coefficients www.(\pm). 25.
Daim duab 10 piv \({Eu}_{90}\) nrog rau qhov kev sim ntawm qhov sib npaug.(16).Qhov nruab nrab tus txheeb ze sib txawv yog 25%, thiab kev ntseeg siab yog 95%.
Phab ntsa Euler tus naj npawb ntawm \(\theta = {90}^{o}\).Qhov nkhaus no sib npaug rau qhov sib npaug.(16).Created with Gnuplot 5.4, www.gnuplot.info.
Lub zog net \({f}_{n}\) ua rau ntawm lub hauv paus pas nrig perpendicular rau nws axis tuaj yeem xam los ntawm kev sib koom ua ke ntawm lub siab ntawm tus pas nrig raws li hauv qab no:
qhov twg thawj coefficient yog tus pas nrig ntev hauv cov channel, thiab kev sib koom ua ke ntawm 0 thiab 2π.
Qhov projection ntawm \({f}_{n}\) nyob rau hauv cov kev taw qhia ntawm cov dej ntws yuav tsum phim lub siab ntawm lub inlet thiab qhov hluav taws xob ntawm lub channel, tshwj tsis yog muaj kev sib txhuam thaum uas tig mus rau tus pas nrig thiab me me vim tsis tiav kev loj hlob ntawm cov seem tom qab lub zog flux yog unbalanced.Yog li ntawd,
Daim duab 11 qhia ib daim duab ntawm qhov sib npaug.(20) pom pom zoo rau txhua qhov kev sim.Txawm li cas los xij, muaj qhov sib txawv me ntsis ntawm 8% ntawm sab xis, uas tuaj yeem raug ntaus nqi thiab siv raws li kev kwv yees ntawm lub zog tsis txaus ntawm cov channel inlet thiab qhov hluav taws xob.
Channel zog sib npaug.Cov kab sib npaug rau qhov sib npaug.(20).Pearson correlation coefficient yog 0.97.Created nrog Gnuplot 5.4, www.gnuplot.info.
Kev sib txawv ntawm lub kaum sab xis ntawm tus pas nrig, lub siab ntawm lub pas nrig nto phab ntsa thiab lub siab poob hauv cov channel nrog cov kab sib hloov ntawm plaub qhov inclined cylindrical rods tau ntsuas.Peb qhov sib txawv ntawm txoj kab uas hla pas nrig sib dhos tau raug sim.In qhov kev ntsuam xyuas Reynolds tus naj npawb ntau, ntawm 2500 thiab 6500, Euler tus lej ntsuas qhov nruab nrab ntawm qhov sib txawv ntawm qhov sib txawv ntawm qhov nruab nrab. qhov siab tshaj plaws nyob rau hauv pem hauv ntej thiab yam tsawg kawg nkaus ntawm qhov sib txawv ntawm cov rods, rov qab los ntawm lub nraub qaum vim yog ciam teb sib cais.
Kev sim cov ntaub ntawv raug soj ntsuam siv lub zog txuag kev txiav txim siab thiab kev ntsuam xyuas ib nrab ntawm qhov pom kom pom cov lej tsis sib xws uas cuam tshuam cov lej Euler rau cov yam ntxwv qhov ntev ntawm cov kab thiab cov pas nrig.Txhua cov duab geometrical ntawm kev thaiv yog tag nrho sawv cev los ntawm qhov sib piv ntawm tus pas nrig txoj kab uas hla thiab qhov sib txawv ntawm cov rods (laterally)).
Lub hauv paus ntsiab lus ntawm kev ywj pheej yog pom los tuav rau feem ntau Euler tooj characterizing siab ntawm qhov chaw sib txawv, piv txwv li yog hais tias lub siab yog dimensionless siv qhov projection ntawm inlet tshaj tawm ib txwm rau tus pas nrig, lub teeb yog ywj siab ntawm lub kaum sab xis.Tsis tas li ntawd, cov yam ntxwv muaj feem xyuam rau qhov loj thiab lub zog ntawm qhov ntws Cov kev txuag kev sib npaug yog zoo ib yam thiab txhawb cov ntsiab lus saum toj no.Tsuas yog cov pas nrig nto siab ntawm qhov sib txawv ntawm cov pas nrig deviates me ntsis los ntawm txoj cai no.Dimensionless semi-empirical correlations yog generated uas yuav siv tau los tsim cov khoom siv hydraulic zoo sib xws.Qhov no classical mus kom ze ntawm qhov sib txawv ntawm cov rods deviates me ntsis los ntawm lub hauv paus ntsiab lus no.Dimensionless semi-empirical correlations yog generated uas yuav siv tau los tsim ib tug zoo xws li hydraulic li.Qhov no classical mus kom ze ntawm 2 dynamical kev siv nws yog raws li qu's dynamic. 1, 22, 23, 24.
Ib qho txiaj ntsig tshwj xeeb yog tshwm sim los ntawm kev tsom xam ntawm qhov poob siab ntawm qhov nkag thiab qhov hluav taws xob ntawm qhov kev xeem seem.Nyob rau hauv qhov kev sim tsis paub meej, cov txiaj ntsig rub tau sib npaug sib npaug, uas qhia txog qhov muaj nyob ntawm qhov tsis sib xws hauv qab no:
Nco ntsoov qhov luaj li cas \(\left(d/g+2\right)d/g\) nyob rau hauv lub denominator ntawm qhov sib npaug.(23) yog qhov loj hauv kab lus hauv kab zauv.(4), txwv tsis pub nws tuaj yeem suav nrog qhov tsawg kawg nkaus thiab pub dawb hla ntu perpendicular mus rau tus pas nrig, \({A}_{m}\) thiab qhov qub yog qhov ({A}_{m}\). Qhov ntau ntawm cov kev tshawb fawb tam sim no (40,000-67,000 rau cov channel thiab 2500-6500 rau cov pas nrig). Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias yog tias muaj qhov kub thiab txias sib txawv hauv cov channel, nws yuav cuam tshuam rau cov kua dej ntom ntom.Qhov no, tus txheeb ze hloov pauv hauv Euler tus lej tuaj yeem kwv yees los ntawm kev sib npaug ntawm cov thermal expansion coefficient los ntawm qhov siab tshaj plaws kub qhov sib txawv.
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Liu, S., Dou, X., Zeng, Q. & Liu, J. Qhov tseem ceeb ntawm cov nyhuv ntawm Jamin nyob rau hauv capillaries nrog constricted cross-sections.J.Gasoline.science.Britain.196, 107635 (2021).