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Kuyesera kunachitika mu njira yozungulira yotsekedwa ndi mizere yopingasa ya ndodo zinayi zozungulira. Kupanikizika pamwamba pa ndodo yapakati ndi kutsika kwa kupanikizika kudutsa njirayo kunayesedwa posintha ngodya ya kupendekera kwa ndodo. Misonkhano itatu yosiyanasiyana ya ndodo ya mainchesi inayesedwa. Zotsatira za muyeso zimasanthulidwa pogwiritsa ntchito mfundo yosungira mphamvu ndi zinthu zoganizira mozama. Ma seti angapo osasinthika a magawo opanda miyeso amapangidwa omwe amagwirizanitsa kupanikizika pamalo ofunikira a dongosolo ndi miyeso ya ndodo. Mfundo yodziyimira pawokha imapezeka kuti imagwira ntchito pa manambala ambiri a Euler omwe amawonetsa kupanikizika m'malo osiyanasiyana, mwachitsanzo ngati kupanikizika kuli kopanda miyeso pogwiritsa ntchito kuwonetsera kwa liwiro lolowera lomwe lili lofanana ndi ndodo, setiyo silidalira ngodya yolowera. Kugwirizana komwe kumachitika kungagwiritsidwe ntchito pakupanga ma hydraulics ofanana.
Zipangizo zambiri zotenthetsera ndi kusamutsa misa zimakhala ndi ma module, njira kapena maselo omwe madzi amadutsamo m'mapangidwe ovuta kwambiri monga ndodo, ma buffer, ma inserts, ndi zina zotero. Posachedwapa, pakhala chidwi chatsopano chofuna kumvetsetsa bwino njira zomwe zimalumikiza kugawa kwa kupanikizika kwamkati ndi mphamvu pa zinthu zovuta zamkati ndi kutsika kwa kupanikizika kwa module yonse. Pakati pa zinthu zina, chidwi ichi chalimbikitsidwa ndi zatsopano mu sayansi ya zinthu, kukulitsa luso la makompyuta la kuyerekezera manambala, komanso kuwonjezeka kwa kuchepetsedwa kwa zida. Kafukufuku waposachedwa wa kugawa kwa kupanikizika kwamkati ndi kutayika kumaphatikizapo njira zolumikizidwa ndi nthiti zosiyanasiyana zooneka ngati 1, maselo a electrochemical reactor 2, kutsekeka kwa capillary 3 ndi zida za lattice frame 4.
Kapangidwe ka mkati kamene kamapezeka kwambiri ndi ndodo zozungulira kudzera mu mayunitsi, kaya zolumikizidwa kapena zodzipatula. Mu zosinthira kutentha, kasinthidwe aka ndi kabwino kwambiri kumbali ya chipolopolo. Kutsika kwa kuthamanga kwa chipolopolo kumagwirizana ndi kapangidwe ka zosinthira kutentha monga majenereta a nthunzi, zokondetsa ndi zotulutsa mpweya. Mu kafukufuku waposachedwa, Wang et al. 5 adapeza momwe kayendedwe kake kamagwirizanirana ndi kugawanikana kake ka ma tandem. Liu et al.6 anayeza kutsika kwa kuthamanga m'njira zozungulira zokhala ndi machubu awiri opangidwa ndi U okhala ndi ma ngodya osiyanasiyana opendekera ndipo adalinganiza chitsanzo cha manambala chotsanzira machubu a ndodo okhala ndi ma porous media.
Monga momwe zikuyembekezeredwa, pali zinthu zingapo zomwe zimakhudza magwiridwe antchito a hydraulic a silinda: mtundu wa dongosolo (monga staggered kapena in-line), miyeso yofanana (monga pitch, diameter, length), ndi inclination angle, pakati pa zina. Olemba angapo adayang'ana kwambiri pakupeza njira zopanda miyeso kuti zitsogolere mapangidwe kuti agwire zotsatira zophatikizana za geometric parameters. Mu kafukufuku waposachedwa, Kim et al. 7 adapereka chitsanzo chogwira ntchito cha porosity pogwiritsa ntchito kutalika kwa unit cell ngati parameter yowongolera, pogwiritsa ntchito tandem ndi staggered arrays ndi manambala a Reynolds pakati pa 103 ndi 104. Snarski8 adaphunzira momwe power spectrum, kuchokera ku accelerometers ndi hydrophones zomwe zimalumikizidwa ku silinda mu ngalande yamadzi, zimasiyana malinga ndi momwe kayendedwe ka madzi kamayendera. Marino et al. 9 adaphunzira kugawa kwa kuthamanga kwa khoma mozungulira ndodo ya cylindrical mu yaw airflow. Mityakov et al. 10 adajambula velocity field pambuyo pa yawed silinda pogwiritsa ntchito stereo PIV.Alam et al. 11 adachita kafukufuku wokwanira wa masilinda a tandem, poyang'ana kwambiri zotsatira za chiwerengero cha Reynolds ndi geometric ratio pa kutayika kwa vortex. Anatha kuzindikira maiko asanu, omwe ndi kutseka, kutseka kosasinthasintha, kutseka kosasinthika, kutseka kwa subharmonic ndi mayendedwe olumikizirana ndi shear layer. Kafukufuku waposachedwa wa manambala wasonyeza kupangika kwa mapangidwe a ma vortex mu kayendedwe ka ma silinda ochepetsedwa.
Kawirikawiri, magwiridwe antchito a hydraulic a unit cell akuyembekezeka kudalira kapangidwe kake ndi geometry ya kapangidwe ka mkati, nthawi zambiri kumayesedwa ndi maubwenzi oyesera a miyeso yeniyeni yoyesera. Mu zida zambiri zopangidwa ndi zigawo za periodic, mapangidwe a flow amabwerezedwa mu selo iliyonse, motero, chidziwitso chokhudzana ndi maselo oyimira chingagwiritsidwe ntchito kufotokoza machitidwe onse a hydraulic a kapangidwe kake kudzera mu mitundu yambiri. Muzochitika izi zofanana, kuchuluka kwa kudziwika komwe mfundo zosungirako zimagwiritsidwa ntchito nthawi zambiri kumatha kuchepetsedwa. Chitsanzo chodziwika bwino ndi equation yotulutsa mbale ya orifice 15. Pankhani yapadera ya ndodo zopendekera, kaya mu flow yotsekedwa kapena yotseguka, muyezo wosangalatsa womwe nthawi zambiri umatchulidwa m'mabuku ndipo umagwiritsidwa ntchito ndi opanga ndi kukula kwakukulu kwa hydraulic (monga, kutsika kwa kupanikizika, mphamvu, kuchuluka kwa vortex shedding, ndi zina zotero) ) kuti igwirizane.) ku flow component perpendicular to cylinder axis. Izi nthawi zambiri zimatchedwa principle yodziyimira pawokha ndipo zimaganiza kuti flow dynamics imayendetsedwa makamaka ndi inflow normal component ndipo kuti zotsatira za axial component zogwirizana ndi cylinder axis ndizochepa. Ngakhale palibe mgwirizano m'mabuku pa kuchuluka kwa kutsimikizika kwa Muyeso uwu, nthawi zambiri umapereka ziwerengero zothandiza mkati mwa kusatsimikizika koyesera komwe kumachitika pakugwirizana kwa empirical. Kafukufuku waposachedwa pa kutsimikizika kwa mfundo yodziyimira payokha akuphatikizapo kugwedezeka komwe kumachitika chifukwa cha vortex16 ndi average-phase ndi two-phase drag417.
Mu ntchito yomweyi, zotsatira za kafukufuku wa kupanikizika kwamkati ndi kutsika kwa kupanikizika mu njira yokhala ndi mzere wopingasa wa ndodo zinayi zozungulira zaperekedwa. Yesani magulu atatu a ndodo okhala ndi mainchesi osiyanasiyana, kusintha ngodya ya kupendekera. Cholinga chachikulu ndikufufuza momwe kufalikira kwa kupanikizika pamwamba pa ndodo kumagwirizanirana ndi kutsika kwa kupanikizika konse mu njira. Deta yoyesera imasanthulidwa pogwiritsa ntchito equation ya Bernoulli ndi mfundo yosungira mphamvu kuti aone ngati mfundo yodziyimira payokha ndi yolondola. Pomaliza, ma correlations opanda miyeso amapangidwa omwe angagwiritsidwe ntchito kupanga zida zofanana za hydraulic.
Kukhazikitsa koyesera kunali ndi gawo loyesera la rectangular lomwe limalandira mpweya woperekedwa ndi fan ya axial. Gawo loyesera lili ndi gawo lokhala ndi ndodo ziwiri zofananira zapakati ndi ndodo ziwiri za theka zomwe zili m'makoma a njira, monga momwe zasonyezedwera pa Chithunzi 1e, zonse zokhala ndi mainchesi ofanana. Zithunzi 1a–e zikuwonetsa mawonekedwe ndi miyeso ya gawo lililonse la kukhazikitsa koyesera. Chithunzi 3 chikuwonetsa kukhazikitsa kwa njira.
Gawo lolowera (kutalika mu mm). Pangani b pogwiritsa ntchito Openscad 2021.01, openscad.org. Gawo lalikulu loyesera (kutalika mu mm). Lopangidwa ndi Openscad 2021.01, openscad.org c Mawonekedwe opingasa a gawo lalikulu loyesera (kutalika mu mm). Lopangidwa pogwiritsa ntchito Openscad 2021.01, openscad.org d gawo lotumizira (kutalika mu mm). Lopangidwa ndi Openscad 2021.01, mawonekedwe ophulika a gawo loyesera la openscad.org e. Lopangidwa ndi Openscad 2021.01, openscad.org.
Ma seti atatu a ndodo za mainchesi osiyanasiyana adayesedwa. Gome 1 limalemba mawonekedwe a geometrical a chikwama chilichonse. Ndodozo zimayikidwa pa protractor kotero kuti ngodya yawo yokhudzana ndi kayendedwe ka madzi imatha kusiyana pakati pa 90° ndi 30° (Zithunzi 1b ndi 3). Ndodo zonse zimapangidwa ndi chitsulo chosapanga dzimbiri ndipo zimayikidwa pakati kuti zikhale ndi mtunda wofanana pakati pawo. Malo ofanana a ndodozo amakhazikika ndi ma spacer awiri omwe ali kunja kwa gawo loyesera.
Kuchuluka kwa madzi olowera mu gawo loyesera kunayesedwa ndi venturi yolinganizidwa, monga momwe zasonyezedwera pa Chithunzi 2, ndikuyang'aniridwa pogwiritsa ntchito DP Cell Honeywell SCX. Kutentha kwa madzi pamalo otulukira gawo loyesera kunayesedwa ndi thermometer ya PT100 ndikuwongoleredwa pa 45±1°C. Kuti zitsimikizire kufalikira kwa liwiro lolinganizidwa ndikuchepetsa kuchuluka kwa kugwedezeka pakhomo la ngalande, madzi olowa amakakamizidwa kudzera mu zotchingira zitatu zachitsulo. Mtunda wokhazikika wa pafupifupi ma diameter anayi a hydraulic unagwiritsidwa ntchito pakati pa chophimba chomaliza ndi ndodo, ndipo kutalika kwa malo otulukira kunali ma diameter 11 a hydraulic.
Chithunzi chojambulidwa cha chubu cha Venturi chomwe chimagwiritsidwa ntchito poyesa liwiro la kulowa kwa madzi (kutalika mu mamilimita). Chopangidwa ndi Openscad 2021.01, openscad.org.
Yang'anirani kupanikizika pa mbali imodzi ya ndodo yapakati pogwiritsa ntchito mpope wa 0.5 mm pakati pa gawo loyesera. M'mimba mwake wa mpope ukugwirizana ndi span ya angular ya 5°; chifukwa chake kulondola kwa angular kuli pafupifupi 2°. Ndodo yoyang'aniridwa ikhoza kuzunguliridwa mozungulira mzere wake, monga momwe zasonyezedwera pa Chithunzi 3. Kusiyana pakati pa kupsinjika kwa pamwamba pa ndodo ndi kupsinjika pakhomo lolowera gawo loyesera kumayesedwa ndi mndandanda wosiyana wa DP Cell Honeywell SCX. Kusiyana kwa kupsinjika kumeneku kumayesedwa pa dongosolo lililonse la mipiringidzo, liwiro losinthasintha la kuyenda, ngodya yopendekera \(\alpha \) ndi ngodya ya azimuth \(\theta \).
Makonzedwe a kayendedwe ka madzi. Makoma a njira akuwonetsedwa mu imvi. Kuyenda kwa madzi kumayenda kuchokera kumanzere kupita kumanja ndipo kumatsekedwa ndi ndodo. Dziwani kuti mawonekedwe "A" ndi olunjika ku mzere wa ndodo. Ndodo zakunja zimayikidwa pang'ono m'makoma a lateral channel. Protractor imagwiritsidwa ntchito kuyeza ngodya ya kupendekera \(\alpha \). Yopangidwa ndi Openscad 2021.01, openscad.org.
Cholinga cha kuyeseraku ndi kuyeza ndikutanthauzira kutsika kwa kuthamanga pakati pa malo olowera njira ndi kuthamanga pamwamba pa ndodo yapakati, \(\theta\) ndi \(\alpha\) pa azimuth ndi dips zosiyanasiyana. Pofotokozera mwachidule zotsatira zake, kuthamanga kosiyana kudzafotokozedwa mu mawonekedwe opanda miyeso monga nambala ya Euler:
kumene \(\rho \) ndi kuchuluka kwa madzi, \({u}_{i}\) ndi liwiro lapakati lolowera, \({p}_{i}\) ndi kuthamanga kwa kulowa, ndipo \({p }_{ w}\) ndi kuthamanga pamalo enaake pakhoma la ndodo. Liwiro la kulowa limakhazikika mkati mwa magawo atatu osiyanasiyana otsimikiziridwa ndi kutseguka kwa valavu yolowera. Ma liwiro omwe amachokera amakhala kuyambira 6 mpaka 10 m/s, mogwirizana ndi nambala ya channel Reynolds, \(Re\equiv {u}_{i}H/\nu \) (komwe \(H\) ndi kutalika kwa channel, ndipo \(\nu \) ndi kinematic viscosity) pakati pa 40,000 ndi 67,000. Nambala ya ndodo Reynolds (\(Re\equiv {u}_{i}d/\nu \)) imakhala kuyambira 2500 mpaka 6500. Mphamvu ya turbulence imayesedwa ndi kusiyana kwa zizindikiro zomwe zalembedwa mu venturi ndi 5% pa avareji.
Chithunzi 4 chikuwonetsa mgwirizano wa \({Eu}_{w}\) ndi ngodya ya azimuth \(\theta \), yomwe imayikidwa ndi ma ngodya atatu ozungulira, \(\alpha \) = 30°, 50° ndi 70° . Miyeso imagawidwa m'ma graph atatu malinga ndi kukula kwa ndodo. Zitha kuwoneka kuti mkati mwa kusatsimikizika koyesera, manambala a Euler omwe apezeka sadalira kuchuluka kwa kuyenda. Kudalira kwakukulu pa θ kumatsatira njira yachizolowezi ya kuthamanga kwa khoma kuzungulira chopinga chozungulira. Pa ngodya zoyang'ana kuyenda, mwachitsanzo, θ kuchokera 0 mpaka 90°, kuthamanga kwa khoma la ndodo kumachepa, kufika pa 90°, zomwe zikugwirizana ndi kusiyana pakati pa ndodo komwe liwiro ndi lalikulu chifukwa cha malire a malo oyenda. Pambuyo pake, pali kubwezeretsedwa kwa kuthamanga kwa θ kuchokera 90° mpaka 100°, pambuyo pake kuthamanga kumakhalabe kofanana chifukwa cha kulekanitsidwa kwa gawo lakumbuyo la khoma la ndodo. Dziwani kuti palibe kusintha kwa ngodya ya kuthamanga kochepa, zomwe zikusonyeza kuti kusokonezeka komwe kungachitike kuchokera ku zigawo zoyandikana nazo za shear, monga zotsatira za Coanda, ndi zachiwiri.
Kusintha kwa nambala ya Euler ya khoma lozungulira ndodo kuti pakhale ma angles osiyanasiyana opendekera ndi mainchesi a ndodo. Yopangidwa ndi Gnuplot 5.4, www.gnuplot.info.
Mu zotsatirazi, tikuwunika zotsatirazo potengera lingaliro lakuti manambala a Euler amatha kuyerekezeredwa ndi magawo a geometric okha, mwachitsanzo, ma feature length ratios \(d/g\) ndi \(d/H\) (komwe \(H\) ndi kutalika kwa njira) ndi kupendekera \(\alpha \). Lamulo lodziwika bwino la thumb limati mphamvu ya kapangidwe ka madzi pa ndodo yaw imatsimikiziridwa ndi projection ya inlet velocity perpendicular to the rod axis, \({u}_{n}={u}_{i}\mathrm {sin} \alpha \) .Izi nthawi zina zimatchedwa mfundo ya kudziyimira pawokha. Chimodzi mwa zolinga za kusanthula uku ndikuwona ngati mfundo iyi ikugwira ntchito pankhaniyi yathu, komwe kuyenda ndi zopinga zimatsekedwa mkati mwa njira zotsekedwa.
Tiyeni tiganizire za kupanikizika komwe kumayesedwa kutsogolo kwa pamwamba pa ndodo yapakati, mwachitsanzo θ = 0. Malinga ndi equation ya Bernoulli, kupanikizika pamalo awa\({p}_{o}\) kumakwaniritsa:
kumene \({u}_{o}\) ndi liwiro lamadzi pafupi ndi khoma la ndodo pa θ = 0, ndipo timaganiza kuti kutayika kochepa kosasinthika. Dziwani kuti kuthamanga kwa mphamvu sikudalira mphamvu ya kinetic. Ngati \({u}_{o}\) kuli kopanda kanthu (kutanthauza mkhalidwe wosasunthika), manambala a Euler ayenera kukhala ogwirizana. Komabe, zitha kuwonedwa mu Chithunzi 4 kuti pa \(\theta =0\) zomwe \({Eu}_{w}\) zomwe zimachokera zili pafupi koma sizili zofanana ndi mtengo uwu, makamaka pa ma angles akuluakulu odumphira. Izi zikusonyeza kuti liwiro pamwamba pa ndodo silitha pa \(\theta =0\), zomwe zingachepetsedwe ndi kupotoza kwa mizere yamakono yopangidwa ndi kupendekera kwa ndodo. Popeza kuyenda kumangika pamwamba ndi pansi pa gawo loyesera, kupotoza kumeneku kuyenera kupanga kubwerezabwereza kwachiwiri, kuwonjezera liwiro la axial pansi ndikuchepetsa liwiro pamwamba. Poganiza kuti kukula kwa kupotoza pamwambapa ndi chiwonetsero cha liwiro lolowera pa shaft (mwachitsanzo \({u}_{i}\mathrm{cos}\alpha \)), zotsatira zofanana za nambala ya Euler ndi izi:
Chithunzi 5 chikuyerekeza ma equation.(3) Chikuwonetsa mgwirizano wabwino ndi deta yoyesera yofanana. Kupatuka kwapakati kunali 25%, ndipo mulingo wodzidalira unali 95%. Onani kuti equation.(3) Mogwirizana ndi mfundo ya kudziyimira pawokha. Momwemonso, Chithunzi 6 chikuwonetsa kuti nambala ya Euler ikugwirizana ndi kupanikizika kumbuyo kwa ndodo, \({p}_{180}\), komanso potuluka gawo loyesera, \({p}_{e}\), Komanso ikutsatira njira yofanana ndi \({\mathrm{sin}}^{2}\alpha \) . Komabe, m'zochitika zonse ziwiri, coefficient imadalira m'mimba mwake wa ndodo, zomwe ndizoyenera popeza yomalizayo imatsimikiza malo olepheretsedwa. Mbali iyi ikufanana ndi kutsika kwa kupanikizika kwa mbale ya orifice, komwe njira yoyendera imachepetsedwa pang'ono pamalo enaake. Mu gawo loyeserali, gawo la orifice limaseweredwa ndi kusiyana pakati pa ndodo. Pankhaniyi, kupanikizika kumatsika kwambiri pakugwedezeka ndikubwerera pang'ono pamene kukukulira mmbuyo. Poganizira zoletsa ngati Kutsekeka kolunjika ku ndodo, kutsika kwa kupanikizika pakati pa kutsogolo ndi kumbuyo kwa ndodo kungalembedwe motere: 18:
kumene \({c}_{d}\) ndi drag coefficient yomwe ikufotokoza kuchira pang'ono kwa kuthamanga pakati pa θ = 90° ndi θ = 180°, ndipo \({A}_{m}\) ndi \ ({A}_{f}\) ndi gawo locheperako laulere pa unit length per perpendicular to the rod axis, ndipo ubale wake ndi m'mimba mwake wa ndodo ndi \({A}_{f}/{A}_{m}=\ ​​Left (g+d\right)/g\). Manambala ofanana a Euler ndi awa:
Nambala ya Wall Euler pa \(\theta =0\) ngati ntchito ya dip. Mzerewu ukugwirizana ndi equation.(3). Yopangidwa ndi Gnuplot 5.4, www.gnuplot.info.
Manambala a Wall Euler amasintha, mu \(\theta =18{0}^{o}\) (chizindikiro chonse) ndi kutuluka (chizindikiro chopanda kanthu) ndi dip. Ma curve awa akugwirizana ndi mfundo ya kudziyimira pawokha, mwachitsanzo \(Eu\propto {\mathrm{sin}}^{2}\alpha \). Yopangidwa ndi Gnuplot 5.4, www.gnuplot.info.
Chithunzi 7 chikuwonetsa kudalira kwa \({Eu}_{0-180}/{\mathrm{sin}}^{2}\alpha \) pa \(d/g\), kusonyeza kusasinthasintha kwabwino kwambiri.(5).Kokwanira kukoka komwe kwapezeka ndi \({c}_{d}=1.28\pm 0.02\) ndi mulingo wodalirika wa 67%.Momwemonso, graph yomweyi ikuwonetsanso kuti kutsika konse kwa kukakamiza pakati pa kulowa ndi kutuluka kwa gawo loyesera kumatsatira njira yofanana, koma ndi ma coefficients osiyanasiyana omwe amaganizira kuchira kwa kukakamiza kumbuyo kwa malo pakati pa bala ndi kutuluka kwa njira.Kokwanira kukoka koyenera ndi \({c}_{d}=1.00\pm 0.05\) ndi mulingo wodalirika wa 67%.
Kokeji yokokera ikugwirizana ndi \(d/g\) kutsika kwa mphamvu kutsogolo ndi kumbuyo kwa ndodo\(\left({Eu}_{0-180}\right)\) ndi kutsika konse kwa mphamvu pakati pa cholowera cha channel ndi outlet. Malo otuwa ndi gulu lodalirika la 67% la mgwirizano. Yopangidwa ndi Gnuplot 5.4, www.gnuplot.info.
Kupanikizika kochepa \({p}_{90}\) pamwamba pa ndodo pa θ = 90° kumafuna kuyendetsedwa mwapadera. Malinga ndi equation ya Bernoulli, pamzere wamakono kudzera pakati pa mipiringidzo, kupanikizika pakati\({p}_{g}\) ndi liwiro\({u}_{g}\) pakati pa mipiringidzo (kumagwirizana ndi pakati pa njira) kumagwirizana ndi zinthu zotsatirazi:
Kupanikizika \({p}_{g}\) kungagwirizane ndi kupanikizika kwa pamwamba pa ndodo pa θ = 90° mwa kuphatikiza kugawa kwa kupanikizika pamwamba pa mpata wolekanitsa ndodo yapakati pakati pa pakati ndi khoma (onani Chithunzi 8). Kulinganiza kwa mphamvu kumapereka 19:
kumene \(y\) ndi coordinate yachibadwa pamwamba pa ndodo kuchokera pakati pa mpata pakati pa ndodo zapakati, ndipo \(K\) ndi kupindika kwa mzere wamakono pamalo \(y\). Pakuwunika kosanthula kwa kupanikizika pamwamba pa ndodo, timaganiza kuti \({u}_{g}\) ndi yofanana ndipo \(K\left(y\right)\) ndi yolunjika. Malingaliro awa atsimikiziridwa ndi mawerengedwe a manambala. Pakhoma la ndodo, kupindika kumatsimikiziridwa ndi gawo la ellipse la ndodo pa ngodya \(\alpha \), mwachitsanzo \(K\left(g/2\right)=\left(2/d\right){\ mathrm{sin} }^{2}\alpha \) (onani Chithunzi 8). Kenako, ponena za kupindika kwa streamline komwe kumasowa pa \(y=0\) chifukwa cha kusinthasintha, kupindika pa universal coordinate \(y\) kumaperekedwa ndi:
Mawonekedwe ozungulira, kutsogolo (kumanzere) ndi pamwamba (pansi). Yopangidwa ndi Microsoft Word 2019,
Kumbali inayi, posunga kulemera, liwiro lapakati pa ndege yolunjika ku kayendedwe ka malo oyezera \(\langle {u}_{g}\rangle \) limagwirizana ndi liwiro la kulowa:
kumene \({A}_{i}\) ndi malo oyendamo odutsa pa malo olowera njira ndipo \({A}_{g}\) ndi malo oyendamo odutsa pa malo oyezera (onani Chithunzi 8) motsatana ndi :
Dziwani kuti \({u}_{g}\) si wofanana ndi \(\langle {u}_{g}\rangle \). Ndipotu, Chithunzi 9 chikuwonetsa chiŵerengero cha liwiro \({u}_{g}/\langle {u}_{g}\rangle \), chowerengedwa ndi equation.(10)–(14), chojambulidwa malinga ndi chiŵerengero \(d/g\). Ngakhale kuti pali kusiyana pang'ono, njira ikhoza kuzindikirika, yomwe imayesedwa ndi polynomial yachiwiri:
Chiŵerengero cha maximum\({u}_{g}\) ndi average\(\langle {u}_{g}\rangle \) liwiro la channel center cross-section\(.\) Ma curve olimba ndi odulidwa amafanana ndi ma equation.(5) ndi kusiyana kwa ma coefficients ogwirizana\(\pm 25\%\). Yopangidwa ndi Gnuplot 5.4, www.gnuplot.info.
Chithunzi 10 chikuyerekeza \({Eu}_{90}\) ndi zotsatira zoyesera za equation.(16). Kupatuka kwapakati kwa ubale kunali 25%, ndipo mulingo wodalirika unali 95%.
Nambala ya Wall Euler pa \(\theta ={90}^{o}\). Kalembedwe aka kakugwirizana ndi equation.(16). Yopangidwa ndi Gnuplot 5.4, www.gnuplot.info.
Mphamvu yonse \({f}_{n}\) yomwe imagwira ntchito pa ndodo yapakati yolunjika ku mzere wake ikhoza kuwerengedwa mwa kuphatikiza kupanikizika pamwamba pa ndodo motere:
kumene coefficient yoyamba ndi kutalika kwa ndodo mkati mwa njira, ndipo kuphatikiza kumachitika pakati pa 0 ndi 2π.
Kuwonekera kwa \({f}_{n}\) motsatira njira yoyendera madzi kuyenera kufanana ndi kupanikizika pakati pa malo olowera ndi otulukira a ngalande, pokhapokha ngati kukangana kuli kofanana ndi ndodo ndipo kuli kochepa chifukwa cha kukula kosakwanira kwa gawo lotsatira. Kuthamanga kwa mphamvu sikuli koyenera. Chifukwa chake,
Chithunzi 11 chikuwonetsa graph ya ma equation.(20) yawonetsa mgwirizano wabwino pazochitika zonse zoyeserera. Komabe, pali kusiyana pang'ono kwa 8% kumanja, komwe kungatchulidwe ndikugwiritsidwa ntchito ngati kuyerekezera kusalingana kwa mphamvu pakati pa cholowera cha channel ndi chotulukira.
Kulinganiza mphamvu ya njira. Mzerewu ukugwirizana ndi equation.(20). Chiŵerengero cha mgwirizano wa Pearson chinali 0.97. Chopangidwa ndi Gnuplot 5.4, www.gnuplot.info.
Posintha ngodya yopendekera ya ndodo, kupanikizika pakhoma la pamwamba pa ndodo ndi kutsika kwa kupanikizika mu njira yokhala ndi mizere yopingasa ya ndodo zinayi zopendekera zinayesedwa. Misonkhano itatu yosiyanasiyana ya ndodo ya mainchesi inayesedwa. Mu chiwerengero cha manambala a Reynolds omwe anayesedwa, pakati pa 2500 ndi 6500, nambala ya Euler siimatengera kuchuluka kwa madzi. Kupanikizika pamwamba pa ndodo yapakati kumatsatira zomwe zimachitika nthawi zonse m'masilinda, kukhala kwakukulu kutsogolo ndi kochepa pampata wa mbali pakati pa ndodo, kubwereranso kumbuyo chifukwa cha kulekanitsidwa kwa malire.
Deta yoyesera imasanthulidwa pogwiritsa ntchito zinthu zoganizira za kusunga mphamvu ndi kuwunika kofanana ndi koyambirira kuti apeze manambala osasinthasintha omwe amagwirizanitsa manambala a Euler ndi miyeso ya njira ndi ndodo. Makhalidwe onse a geometrical a blockade akuimiridwa mokwanira ndi chiŵerengero pakati pa m'mimba mwake wa ndodo ndi kusiyana pakati pa ndodo (mbali) ndi kutalika kwa njira (yoyima).
Mfundo yodziyimira pawokha imapezeka kuti imagwira ntchito pa manambala ambiri a Euler omwe amafotokozera kupanikizika m'malo osiyanasiyana, mwachitsanzo ngati kupanikizika kuli kopanda muyeso pogwiritsa ntchito kuwonetsera kwa liwiro lolowera lomwe lili bwino kwa ndodo, setiyo silidalira ngodya yolowera. Kuphatikiza apo, mawonekedwewa akugwirizana ndi kulemera ndi mphamvu ya kuyenda kwa madzi. Ma equation osungira zinthu ndi ofanana ndipo amathandizira mfundo yowona pamwambapa. Kupanikizika kwa pamwamba pa ndodo kokha komwe kuli pakati pa ndodo kumasiyana pang'ono ndi mfundo iyi. Ma dimensionless semi-empirical correlations amapangidwa omwe angagwiritsidwe ntchito kupanga zida zofanana za hydraulic. Njira yakale iyi ikugwirizana ndi ntchito zomwe zanenedwa posachedwapa za Bernoulli equation ku hydraulics ndi hemodynamics20,21,22,23,24.
Zotsatira zosangalatsa kwambiri zimachokera ku kusanthula kwa kutsika kwa kuthamanga pakati pa malo olowera ndi otulukira a gawo loyesera. Mkati mwa kusatsimikizika kwa kuyesa, kuchuluka kwa kukoka komwe kumachitika kumafanana ndi umodzi, zomwe zimasonyeza kukhalapo kwa magawo osasinthika otsatirawa:
Onani kukula \(\left(d/g+2\right)d/g\) mu denominator ya equation.(23) ndi kukula komwe kuli m'mabulaketi mu equation.(4), apo ayi ikhoza kuwerengedwa ndi gawo locheperako komanso lopanda malire lolunjika pa ndodo, \({A}_{m}\) ndi \({A}_{f}\). Izi zikusonyeza kuti manambala a Reynolds akuyembekezeka kukhalabe mkati mwa kafukufuku wapano (40,000-67,000 pa njira ndi 2500-6500 pa ndodo). Ndikofunikira kudziwa kuti ngati pali kusiyana kwa kutentha mkati mwa njira, kungakhudze kuchuluka kwa madzi. Pankhaniyi, kusintha kwa chiwerengero cha Euler kumatha kuyerekezeredwa pochulukitsa kuchuluka kwa kutentha ndi kusiyana kwakukulu kwa kutentha komwe kumayembekezeredwa.
Ruck, S., Köhler, S., Schlindwein, G., ndi Arbeiter, F. Kuyesa kusamutsa kutentha ndi kutsika kwa kuthamanga mu njira yolumikizidwa ndi nthiti zooneka mosiyana pakhoma. katswiri. Kusamutsa Kutentha 31, 334–354 (2017).
Wu, L., Arenas, L., Graves, J., ndi Walsh, F. Kufotokozera za maselo oyenda: kuwonetsa kayendedwe ka madzi, kutsika kwa kuthamanga kwa madzi, ndi mayendedwe a misa m'ma electrode amitundu iwiri mu njira zozungulira. J. Electrochemistry. Socialist Party.167, 043505 (2020).
Liu, S., Dou, X., Zeng, Q. & Liu, J. Magawo ofunikira a Jamin effect mu capillaries yokhala ndi magawo opingasa. J. Gasoline.science.Britain.196, 107635 (2021).