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A cikin wannan binciken, ana ƙididdige yanayin ruwa na flocculation ta hanyar gwaji da bincike na ƙididdigewa na filin gudu mai ruɗani a cikin ma'aunin ma'aunin dakin gwaje-gwaje.Ƙunƙarar tashin hankali wanda ke inganta haɓakar ƙwayar cuta ko floc breakup yana da wuyar gaske kuma an yi la'akari da shi kuma an kwatanta shi a cikin wannan takarda ta amfani da nau'i biyu na tashin hankali, wato SST k-ω da IDDES.Sakamakon ya nuna cewa IDDES yana ba da ƙaramin haɓakawa akan SST k-ω, wanda ya isa don daidaita kwararar kwararar ruwa a cikin flocculator.Ana amfani da madaidaicin madaidaicin don bincika haɗuwar sakamakon PIV da CFD, da kuma kwatanta sakamakon ƙirar tashin hankali na CFD da aka yi amfani da su.Har ila yau, binciken ya mayar da hankali kan ƙididdige ma'anar zamewar k, wanda shine 0.18 a ƙananan gudu na 3 da 4 rpm idan aka kwatanta da ƙimar da aka saba da ita na 0.25.Rage k daga 0.25 zuwa 0.18 yana ƙara ƙarfin da ake bayarwa ga ruwan da kusan 27-30% kuma yana ƙara saurin saurin (G) da kusan 14%.Wannan yana nufin cewa an sami ƙarin haɗuwa mai ƙarfi fiye da yadda ake tsammani, saboda haka ana amfani da ƙarancin kuzari, sabili da haka amfani da makamashi a cikin rukunin flocculation na injin ruwan sha na iya zama ƙasa.
A cikin tsarkakewar ruwa, ƙari na coagulant yana lalata ƙananan ƙwayoyin colloidal da ƙazanta, waɗanda suka haɗa su don samar da flocculation a matakin flocculation.Filayen ana daure su da yawa na juzu'i, sannan ana cire su ta hanyar daidaitawa.Barbashi Properties da ruwa hadawa yanayi ƙayyade yadda ya dace da flocculation da magani tsari.Juyawa yana buƙatar jinkirin tashin hankali na ɗan gajeren lokaci da ƙarfi mai yawa don tada ruwa mai yawa1.
A lokacin flocculation, da hydrodynamics na dukan tsarin da kuma sunadarai na coagulant-barbashi hulda ƙayyade kudi a wanda a tsaye barbashi size rarraba aka samu2.Idan barbashi suka yi karo, sai su manne da juna3.Oyegbile, Ay4 ya ruwaito cewa karon ya dogara ne akan hanyoyin jigilar tafiye-tafiye na Brownian, juzu'in ruwa da daidaitawa daban-daban.Lokacin da ɓangarorin suka yi karo, sai su girma kuma su kai iyakacin iyaka, wanda zai iya haifar da karyewa, tun da flakes ɗin ba zai iya jure ƙarfin ƙarfin hydrodynamic ba5.Wasu daga cikin ɓangarorin da suka karye suna sake haɗuwa zuwa ƙanana ko girman guda6.Koyaya, flakes masu ƙarfi na iya tsayayya da wannan ƙarfin kuma su kula da girman su har ma girma7.Yukselen da Gregory8 sun ba da rahoto game da binciken da suka shafi lalata flakes da ikon su na sake farfadowa, yana nuna cewa rashin daidaituwa ya iyakance.Bridgeman, Jefferson9 ya yi amfani da CFD don kimanta tasirin gida na matsakaicin kwarara da tashin hankali akan samuwar floc da rarrabuwa ta hanyar matakan saurin gida.A cikin tankuna sanye take da rotor ruwan wukake, ya zama dole don bambanta gudun abin da aggregates karo tare da sauran barbashi a lokacin da aka isasshe destabilized a cikin coagulation lokaci.Ta amfani da CFD da ƙananan saurin juyawa na kusan 15 rpm, Vadasarukkai da Gagnon11 sun sami damar cimma ƙimar G don flocculation tare da ruwan wukake, don haka rage yawan amfani da wutar lantarki don tashin hankali.Koyaya, aiki a ƙimar G mafi girma na iya haifar da flocculation.Sun binciki tasirin gaurayawan gudu akan tantance matsakaita saurin gudu na matuƙin jirgin ruwa.Suna juyawa a gudun fiye da 5 rpm.
Korpijärvi, Ahlstedt12 yayi amfani da nau'ikan hargitsi daban-daban guda huɗu don nazarin filin kwarara akan benci na gwajin tanki.Sun auna filin kwarara tare da Laser Doppler anemometer da PIV kuma sun kwatanta sakamakon ƙididdiga tare da sakamakon da aka auna.de Oliveira da Donadel13 sun ba da shawarar wata hanya dabam don ƙididdige matakan saurin gudu daga kaddarorin hydrodynamic ta amfani da CFD.An gwada hanyar da aka tsara akan raka'o'in flocculation guda shida bisa la'akari da lissafi na helical.kimanta tasirin lokacin riƙewa akan flocculants kuma ya ba da shawarar samfurin flocculation wanda za'a iya amfani dashi azaman kayan aiki don tallafawa ƙirar tantanin halitta mai ma'ana tare da ƙananan lokutan riƙewa14.Zhan, You15 ya ba da shawarar haɗakar CFD da ƙirar ma'aunin yawan jama'a don kwaikwayi halaye masu gudana da halayen ɗumbin ɗumbin ɗumbin yawa.Llano-Serna, Coral-Portillo16 ya binciki halaye masu gudana na nau'in hydroflocculator na Cox-type a cikin masana'antar sarrafa ruwa a Viterbo, Colombia.Kodayake CFD yana da fa'idodinsa, akwai kuma iyakoki kamar kurakuran lambobi a cikin ƙididdiga.Don haka, duk wani sakamakon lambobi da aka samu ya kamata a yi nazari da kuma bincikar su sosai domin a cimma matsaya mai mahimmanci17.Akwai 'yan karatu a cikin wallafe-wallafe game da zane-zane a kwance baffle flocculators, yayin da shawarwarin da aka tsara na hydrodynamic flocculators suna da iyaka18.Chen, Liao19 ya yi amfani da saitin gwaji dangane da tarwatsa hasken wuta don auna yanayin karkatarwar hasken da aka watsar daga ɓangarorin ɗaiɗaikun.Feng, Zhang20 ya yi amfani da Ansys-Fluent don yin kwatankwacin rarraba magudanar ruwa da jujjuyawa a cikin filin kwararar flocculator ɗin faranti mai gaɓoɓi da kuma na'urar sarrafa igiyar ruwa.Bayan yin kwatankwacin kwararar ruwa mai ruɗani a cikin flocculator ta amfani da Ansys-Fluent, Gavi21 ya yi amfani da sakamakon don tsara flocculator.Vaneli da Teixeira22 sun ba da rahoton cewa alaƙar da ke tsakanin motsin ruwa na masu karkatar da bututun mai da kuma tsarin flocculation har yanzu ba a fahimta sosai don tallafawa ƙira ta hankali.de Oliveira da Costa Teixeira23 sun yi nazarin yadda ya dace kuma sun nuna kaddarorin hydrodynamic na karkatacciyar bututu ta hanyar gwaje-gwajen kimiyyar lissafi da kwaikwaiyon CFD.Masu bincike da yawa sun yi nazari kan na'urorin da aka nada ko na'urar flocculators.Koyaya, cikakkun bayanai na hydrodynamic game da martanin waɗannan reactors ga ƙira daban-daban da yanayin aiki har yanzu ba a samu ba (Sartori, Oliveira24; Oliveira, Teixeira25).Oliveira da Teixeira26 suna gabatar da sakamako na asali daga ka'idar, gwaji da kwaikwaiyon CFD na karkace flocculator.Oliveira da Teixeira27 sun ba da shawarar yin amfani da murɗa mai karkace a matsayin mai sarrafa coagulation-flocculation reactor a haɗe da na al'ada decanter tsarin.Suna ba da rahoton cewa sakamakon da aka samu don ingantaccen cire turbidity ya bambanta sosai da waɗanda aka samu tare da samfuran da aka saba amfani da su don kimanta ɗigon ruwa, yana ba da shawarar yin taka tsantsan yayin amfani da irin waɗannan samfuran.Moruzzi da de Oliveira [28] sun tsara halayen tsarin ci gaba da ɗimbin ɗakuna a ƙarƙashin yanayin aiki daban-daban, gami da bambance-bambance a cikin adadin ɗakunan da aka yi amfani da su da kuma amfani da ƙayyadaddun ƙayyadaddun matakan saurin salula.Romphophak, Le Men29 Ma'auni na PIV na saurin sauri a cikin masu tsabtace jet mai girma-biyu.Sun sami ƙarfi mai ƙarfi da ke haifar da jet a cikin yankin flocculation da ƙididdige ƙimar juzu'i na gida da nan take.
Shah, Joshi30 rahoton cewa CFD yana ba da wani zaɓi mai ban sha'awa don haɓaka ƙira da samun halaye masu gudana.Wannan yana taimakawa don gujewa saitin gwaji mai yawa.Ana ƙara yin amfani da CFD don nazarin wuraren sarrafa ruwa da ruwan sha (Melo, Freire31; Alalm, Nasr32; Bridgeman, Jefferson9; Samaras, Zouboulis33; Wang, Wu34; Zhang, Tejada-Martínez35).Masu bincike da yawa sun yi gwaje-gwaje akan iya gwada kayan aiki (Bridgeman, Jefferson36; Bridgeman, Jefferson5; Jarvis, Jefferson6; Wang, Wu34) da kuma masu fafutikar fayafai31.Wasu sun yi amfani da CFD don kimanta hydroflocculators (Bridgeman, Jefferson5; Vadasarukkai, Gagnon37).Ghawi21 ya ruwaito cewa, injinan injina suna buƙatar kulawa akai-akai saboda yawanci suna lalacewa kuma suna buƙatar wutar lantarki mai yawa.
Ayyukan flocculator na filafili ya dogara sosai akan yanayin ruwa na tafki.Rashin fahimtar yawan fahimtar filayen saurin kwarara a cikin irin waɗannan na'urori an lura da su a fili a cikin wallafe-wallafen (Howe, Hand38; Hendricks39).Duk yawan ruwan ruwa yana ƙarƙashin motsi na flocculator impeller, don haka ana sa ran zamewa.Yawanci, saurin ruwan ya yi ƙasa da saurin ruwan wuka ta hanyar zamewar factor k, wanda aka bayyana a matsayin rabon saurin jikin ruwa zuwa saurin motsin filafili.Bhole40 ya ruwaito cewa akwai wasu abubuwa guda uku da ba a san su ba da za a yi la'akari da su yayin zayyana na'ura mai motsi, wato saurin gudu, ma'aunin ja, da kusancin ruwan ruwa dangane da ruwan wukake.
Camp41 ya ba da rahoton cewa lokacin yin la'akari da injunan saurin sauri, saurin yana kusan kashi 24% na saurin rotor kuma ya kai 32% don ƙananan injunan sauri.Idan babu septa, Droste da Ger42 sun yi amfani da ak darajar 0.25, yayin da a cikin yanayin septa, k ya kasance daga 0 zuwa 0.15.Howe, Hand38 yana ba da shawarar cewa k yana cikin kewayon 0.2 zuwa 0.3.Hendrix39 ya danganta ma'aunin zamewa zuwa saurin jujjuyawa ta amfani da dabara mai ma'ana kuma ya kammala cewa ma'aunin zamewar yana cikin kewayon da Camp41 ya kafa.Bratby43 ya ruwaito cewa k yana kusan 0.2 don saurin impeller daga 1.8 zuwa 5.4 rpm kuma yana ƙaruwa zuwa 0.35 don saurin impeller daga 0.9 zuwa 3 rpm.Sauran masu bincike sun ba da rahoton ƙima mai yawa na ja (Cd) daga 1.0 zuwa 1.8 da zamewa coefficient k ƙimar daga 0.25 zuwa 0.40 (Feir da Geyer44; Hyde da Ludwig45; Harris, Kaufman46; van Duuren47; da Bratby da Marais48 ).Littattafan ba su nuna babban ci gaba ba wajen ma'ana da ƙididdigewa k tun aikin Camp41.
Tsarin flocculation yana dogara ne akan tashin hankali don sauƙaƙe haɗuwa, inda ake amfani da gradient mai saurin gudu (G) don auna hargitsi.Hadawa shine tsarin tarwatsa sinadarai cikin sauri da ko'ina cikin ruwa.Ana auna matakin haɗawa ta hanyar saurin saurin:
inda G = saurin gradient (sec-1), P = shigar da wutar lantarki (W), V = ƙarar ruwa (m3), μ = danko mai ƙarfi (Pa s).
Mafi girman ƙimar G, ƙarin gauraye.Cakuda sosai yana da mahimmanci don tabbatar da coagulation iri ɗaya.Littattafan sun nuna cewa mafi mahimmancin sigogin ƙira sune haɗakar lokaci (t) da saurin saurin gudu (G).Tsarin flocculation yana dogara ne akan tashin hankali don sauƙaƙe haɗuwa, inda ake amfani da gradient mai saurin gudu (G) don auna hargitsi.Yawan ƙira na G shine 20 zuwa 70 s-1, t shine 15 zuwa 30 mintuna, kuma Gt (marasa girma) shine 104 zuwa 105. Tankuna masu sauri suna aiki mafi kyau tare da ƙimar G na 700 zuwa 1000, tare da tsayawa lokaci. kamar minti 2.
inda P shine ikon da kowane ruwan ruwa ya ba ruwa, N shine saurin juyawa, b shine tsayin ruwa, ρ shine yawan ruwa, r shine radius, kuma k shine madaidaicin zamewa.Ana amfani da wannan ma'auni ga kowane ruwa a ɗaiɗaiku kuma ana tattara sakamakon don ba da jimillar shigar da wutar lantarki na flocculator.Binciken da aka yi a hankali game da wannan ma'auni yana nuna mahimmancin ma'aunin zamewa k a cikin tsarin ƙira na flocculator.Littattafan ba su faɗi ainihin ƙimar k ba, a maimakon haka suna ba da shawarar kewayon kamar yadda aka bayyana a baya.Koyaya, alaƙar da ke tsakanin ikon P da madaidaicin zamewa k shine cubic.Don haka, idan har dukkan sigogi sun kasance iri ɗaya, misali, canza k daga 0.25 zuwa 0.3 zai haifar da raguwar ikon da ake watsawa ga ruwa a kowace ruwa da kusan 20%, kuma rage k daga 0.25 zuwa 0.18 zai ƙara mata.da kusan 27-30% kowace vane Ikon da aka ba ruwan.A ƙarshe, tasirin k akan ƙirar flocculator mai ɗorewa yana buƙatar bincika ta hanyar ƙididdigewa na fasaha.
Madaidaicin ƙididdige ƙididdigewa na zamewa yana buƙatar hangen nesa da kwaikwaya.Sabili da haka, yana da mahimmanci don bayyana saurin tangential na ruwa a cikin ruwa a wani saurin juyawa a nisan radial daban-daban daga shaft da kuma zurfin zurfi daga saman ruwa don kimanta tasirin matsayi daban-daban.
A cikin wannan binciken, ana ƙididdige yanayin ruwa na flocculation ta hanyar gwaji da bincike na ƙididdigewa na filin gudu mai ruɗani a cikin ma'aunin ma'aunin dakin gwaje-gwaje.Ana yin rikodin ma'auni na PIV akan flocculator, ƙirƙirar matsakaicin tsayin lokaci mai nuna saurin barbashi na ruwa a kusa da ganye.Bugu da ƙari, an yi amfani da ANSYS-Fluent CFD don yin kwatankwacin ɗigon ruwa a cikin flocculator da ƙirƙirar matsakaicin matsakaicin lokaci.An tabbatar da samfurin CFD da aka samu ta hanyar kimanta ma'amala tsakanin sakamakon PIV da CFD.Manufar wannan aikin shine ƙididdige madaidaicin zamewar k, wanda shine ma'aunin ƙira mara girma na flocculator.Aikin da aka gabatar anan yana ba da sabon tushe don ƙididdige ƙididdige ƙimar zamewa k a ƙananan gudu na 3rpm da 4 rpm.Abubuwan da ke haifar da sakamakon kai tsaye suna ba da gudummawa ga ingantaccen fahimtar yanayin ruwa na tankin flocculation.
Gidan dakin gwaje-gwajen ya ƙunshi akwatin buɗaɗɗen saman sama mai rectangular tare da tsayin tsayin 147 cm, tsayin 39 cm, faɗin faɗin cm 118 gabaɗaya, da tsayin 138 cm gabaɗaya (Fig. 1).Babban ma'aunin ƙira da Camp49 ya haɓaka an yi amfani da su don ƙirƙira ma'aunin ma'auni na dakin gwaje-gwaje da amfani da ƙa'idodin ƙididdigar ƙima.An gina wurin gwajin a dakin gwaje-gwajen Injiniyan Muhalli na Jami'ar Amurka ta Lebanon (Byblos, Lebanon).
A kwance axis yana samuwa a tsawo na 60 cm daga ƙasa kuma yana ɗaukar ƙafafun ƙafa biyu.Kowace dabarar ta ƙunshi paddles guda 4 tare da paddles 3 akan kowane filafili don jimlar 12 paddles.Juyawa yana buƙatar tashin hankali a ƙaramin gudun 2 zuwa 6 rpm.Mafi yawan saurin haɗawa a cikin flocculators shine 3 rpm da 4 rpm.An tsara ma'aunin flocculator na dakin gwaje-gwaje don wakiltar magudanar ruwa a cikin sashin tankin flocculation na masana'antar sarrafa ruwan sha.Ana ƙididdige ƙarfi ta amfani da ma'auni na gargajiya 42 .Domin duka saurin jujjuyawa biyu, saurin gradient \(\stackrel{\mathrm{-}}{\text{G}}\) ya fi 10 \({\text{sec}}}^{-{1}}\) , lambar Reynolds tana nuna tashin hankali (Table 1).
Ana amfani da PIV don cimma daidaitattun ma'auni na ma'aunin saurin ruwa a lokaci guda a adadi mai yawa na maki50.Saitin gwajin ya haɗa da flocculator mai sikelin sikelin lab, tsarin LaVision PIV (2017), da firikwensin Laser na waje na Arduino.Don ƙirƙirar matsakaicin bayanan bayanan saurin lokaci, an yi rikodin hotunan PIV a jere a wuri guda.An daidaita tsarin PIV ta yadda yankin da aka nufa ya kasance a tsakiyar tsayin kowane nau'in ruwan wukake guda uku na wani hannu na musamman.Ƙunƙarar faɗakarwa ta waje ta ƙunshi laser da ke gefe ɗaya na faɗin flocculator da mai karɓar firikwensin a wancan gefen.Duk lokacin da hannun flocculator ya toshe hanyar Laser, ana aika sigina zuwa tsarin PIV don ɗaukar hoto tare da Laser na PIV da kyamarar da aka daidaita tare da naúrar lokacin shirye-shirye.A kan fig.2 yana nuna shigarwa na tsarin PIV da tsarin sayan hoto.
An fara rikodi na PIV bayan an yi amfani da flocculator na tsawon mintuna 5-10 don daidaita kwararar ruwa kuma a yi la'akari da filin firikwensin refractive iri ɗaya.Ana samun gyare-gyare ta hanyar amfani da farantin gyare-gyaren da aka nutsar a cikin flocculator kuma an sanya shi a tsakiyar tsakiyar tsayin ruwan sha'awa.Daidaita matsayi na Laser PIV don samar da takardar haske mai lebur kai tsaye sama da farantin daidaitawa.Yi rikodin ƙimar da aka auna don kowane saurin juyawa na kowane ruwa, kuma saurin juyawa da aka zaɓa don gwajin shine 3 rpm da 4 rpm.
Ga duk rikodi na PIV, tazarar lokaci tsakanin bugun laser guda biyu an saita shi a cikin kewayo daga 6900 zuwa 7700 µs, wanda ya ba da izinin matsar da ƙaramin yanki na 5 pixels.An yi gwajin matukin jirgi akan adadin hotunan da ake buƙata don samun ingantattun ma'auni na lokaci.An kwatanta kididdigar vector don samfurori masu ɗauke da hotuna 40, 50, 60, 80, 100, 120, 160, 200, 240, da 280 hotuna.An samo girman samfurin hotuna 240 don ba da tabbataccen sakamako mai matsakaicin lokaci ganin cewa kowane hoto ya ƙunshi firam biyu.
Tun da kwararar ruwa a cikin flocculator yana da tashin hankali, ana buƙatar ƙaramin taga tambayoyi da adadi mai yawa don warware ƙananan sifofi masu tayar da hankali.Ana amfani da gyare-gyare da yawa na raguwar girma tare da haɗin gwiwar haɗin kai don tabbatar da daidaito.Girman taga na farko na 48 × 48 pixels tare da 50% zoba kuma tsarin daidaitawa guda ɗaya ya biyo baya da girman taga kuri'a na ƙarshe na pixels 32 × 32 tare da zoba 100% da matakan daidaitawa guda biyu.Bugu da kari, an yi amfani da filayen gilashin a matsayin nau'in iri a cikin kwararar, wanda ya ba da damar a kalla barbashi 10 a kowace taga zabe.Rikodin PIV yana haifar da tushen faɗakarwa a cikin Sashin Lokaci na Shirye-shiryen (PTU), wanda ke da alhakin aiki da aiki tare da tushen Laser da kyamara.
An yi amfani da fakitin CFD na kasuwanci ANSYS Fluent v 19.1 don haɓaka ƙirar 3D da warware ainihin daidaitattun kwararar ruwa.
Yin amfani da ANSYS-Fluent, an ƙirƙiri samfurin 3D na ma'aunin filafili na dakin gwaje-gwaje.An yi samfurin a cikin akwatin akwatin rectangular, wanda ya ƙunshi ƙafafun filafili guda biyu waɗanda aka ɗora a kan axis a kwance, kamar samfurin dakin gwaje-gwaje.Samfurin ba tare da allo na kyauta ba shine tsayin 108 cm, faɗin 118 cm da tsayi 138 cm.An ƙara wani jirgin sama silindari a kwance a kusa da mahaɗin.Ya kamata ƙarni na cylindrical jirgin ya aiwatar da jujjuyawar gabaɗayan mahaɗa yayin lokacin shigarwa kuma a kwaikwayi filin jujjuyawa a cikin flocculator, kamar yadda aka nuna a cikin siffa 3a.
3D ANSYS-mai kyau da zane-zanen lissafi na ƙira, ANSYS-sauke ragamar flocculator a kan jirgin sama mai ban sha'awa, ANSYS-tsararren zane akan jirgin sha'awa.
Geometry na samfurin ya ƙunshi yankuna biyu, kowannensu ruwa ne.Ana samun wannan ta amfani da aikin rage ma'ana.Da farko cire Silinda (ciki har da mahaɗa) daga akwatin don wakiltar ruwa.Sa'an nan kuma cire mahaɗin daga silinda, yana haifar da abubuwa biyu: mahaɗin da ruwa.A ƙarshe, an yi amfani da ƙirar zamewa tsakanin wurare guda biyu: ƙirar silinda-cylinder da silinda-mixer interface (Fig. 3a).
An kammala ƙaddamar da ƙirar da aka gina don saduwa da buƙatun ƙirar tashin hankali waɗanda za a yi amfani da su don gudanar da ƙididdiga na ƙididdiga.An yi amfani da raga marar tsari tare da faɗaɗa yadudduka kusa da ƙaƙƙarfan farfajiya.Ƙirƙirar yadudduka na faɗaɗa don duk bangon tare da ƙimar girma na 1.2 don tabbatar da cewa an kama sarƙaƙƙun tsarin gudana, tare da kauri na farko na \(7\mathrm{x }{10}^{-4}\) m don tabbatar da cewa \ ( {\rubutu {y))^{+}\le 1.0\).Ana daidaita girman jiki ta amfani da hanyar dacewa da tetrahedron.An ƙirƙira girman gefen gaba na musaya biyu tare da girman kashi 2.5 × \({10}^{-3}\) m, da girman gaban mahaɗar 9 × \({10}^{-3}\ ) m yana amfani.Rukunin farko da aka samar ya ƙunshi abubuwa 2144409 (Fig. 3b).
An zaɓi samfurin turbulence mai siga biyu k–ε azaman ƙirar tushe ta farko.Don daidaita daidaitaccen magudanar ruwa a cikin flocculator, an zaɓi samfurin mafi tsadar lissafi.An yi binciken magudanar motsi mai ruɗani a cikin flocculator a lamba ta amfani da nau'ikan CFD guda biyu: SST k-ω51 da IDDES52.An kwatanta sakamakon duka samfuran biyu tare da sakamakon gwaji na PIV don inganta samfuran.Na farko, ƙirar tashin hankali na SST k-ω samfurin ɗanko mai ruɗani mai daidaitawa biyu don aikace-aikacen kuzarin ruwa.Wannan samfurin matasan ne wanda ya haɗa samfuran Wilcox k-ω da k-ε.Ayyukan haɗawa yana kunna samfurin Wilcox kusa da bango da samfurin k-ε a cikin kwarara mai zuwa.Wannan yana tabbatar da cewa ana amfani da samfurin daidai a ko'ina cikin filin gudana.Yana tsinkayar tsinkayar rabuwar kwararar daidai gwargwado saboda matsananciyar matsa lamba.Na biyu, an zaɓi hanyar Advanced Deferred Eddy Simulation (IDDES), wanda aka yi amfani da shi sosai a cikin Tsarin Mutum Eddy Simulation (DES) tare da samfurin SST k-ω RANS (Reynolds-Averaged Navier-Stokes).IDDES shine samfurin RANS-LES (babban eddy simulation) wanda ke ba da mafi sassauƙa da ƙirar ƙirar ƙira mai sauƙin amfani (SRS).Ya dogara ne akan ƙirar LES don warware manyan eddies kuma komawa zuwa SST k-ω don daidaita ƙananan eddies.An kwatanta ƙididdigar ƙididdiga na sakamakon daga SST k-ω da IDDES simulations tare da sakamakon PIV don inganta samfurin.
An zaɓi samfurin turbulence mai siga biyu k–ε azaman ƙirar tushe ta farko.Don daidaita daidaitaccen magudanar ruwa a cikin flocculator, an zaɓi samfurin mafi tsadar lissafi.An yi binciken magudanar motsi mai ruɗani a cikin flocculator a lamba ta amfani da nau'ikan CFD guda biyu: SST k-ω51 da IDDES52.An kwatanta sakamakon duka samfuran biyu tare da sakamakon gwaji na PIV don inganta samfuran.Na farko, ƙirar tashin hankali na SST k-ω samfurin ɗanko mai ruɗani mai daidaitawa biyu don aikace-aikacen kuzarin ruwa.Wannan samfurin matasan ne wanda ya haɗa samfuran Wilcox k-ω da k-ε.Ayyukan haɗawa yana kunna samfurin Wilcox kusa da bango da samfurin k-ε a cikin kwarara mai zuwa.Wannan yana tabbatar da cewa ana amfani da samfurin daidai a ko'ina cikin filin gudana.Yana tsinkayar tsinkayar rabuwar kwararar daidai gwargwado saboda matsananciyar matsa lamba.Na biyu, an zaɓi hanyar Advanced Deferred Eddy Simulation (IDDES), wanda aka yi amfani da shi sosai a cikin Tsarin Mutum Eddy Simulation (DES) tare da samfurin SST k-ω RANS (Reynolds-Averaged Navier-Stokes).IDDES shine samfurin RANS-LES (babban eddy simulation) wanda ke ba da mafi sassauƙa da ƙirar ƙirar ƙira mai sauƙin amfani (SRS).Ya dogara ne akan ƙirar LES don warware manyan eddies kuma komawa zuwa SST k-ω don daidaita ƙananan eddies.An kwatanta ƙididdigar ƙididdiga na sakamakon daga SST k-ω da IDDES simulations tare da sakamakon PIV don inganta samfurin.
Yi amfani da matsi mai ƙarfi na wucin gadi kuma yi amfani da nauyi a cikin hanyar Y.Ana samun juyawa ta hanyar sanya motsin raga zuwa mahaɗar, inda asalin juzu'in jujjuyawar ke tsakiyar tsakiyar axis kuma hanyar jujjuyawar jujjuyawar tana cikin hanyar Z.An ƙirƙiri keɓan mahaɗar raga don mu'amalar lissafi na ƙirar ƙira, wanda ya haifar da gefuna biyu masu ɗaure fuska.Kamar yadda yake a cikin fasahar gwaji, saurin juyawa yayi daidai da juyi 3 da 4.
Yanayin iyaka don ganuwar mahaɗin da flocculator an saita bangon, kuma an saita saman buɗewar flocculator ta hanyar fita tare da ma'aunin sifili (Fig. 3c).SAUKI Tsarin sadarwa na matsa lamba-gudun sauri, ɓata sararin sarari na ayyuka na biyu tare da duk sigogin da ya dogara da akalla abubuwan murabba'ai.Ma'auni na haɗin kai don duk masu canjin kwarara shine ragowar 1 x \ ({10}^{-3} \).Matsakaicin adadin maimaitawa a kowane mataki na lokaci shine 20, kuma girman matakin lokacin yayi daidai da jujjuyawar 0.5°.Maganin yana haɗuwa a 8th iteration don samfurin SST k-ω kuma a 12th maimaitawa ta amfani da IDDES.Bugu da ƙari, an ƙididdige adadin matakan lokaci don mahaɗin ya yi aƙalla juyi 12.Aiwatar da samfurin bayanai don kididdigar lokaci bayan juyawa 3, wanda ke ba da damar daidaita kwararar ruwa, kama da hanyar gwaji.Kwatanta fitar da madaukai masu sauri ga kowane juyi yana ba da sakamako iri ɗaya na juyi huɗu na ƙarshe, wanda ke nuni da cewa an kai ga daidaiton yanayi.Ƙarin revs bai inganta matsakaicin matakan saurin gudu ba.
An bayyana matakin lokacin dangane da saurin juyi, 3 rpm ko 4 rpm.Ana tace matakin lokacin zuwa lokacin da ake buƙata don juya mahaɗin ta 0.5°.Wannan ya zama isa, tun da maganin yana haɗuwa cikin sauƙi, kamar yadda aka bayyana a cikin sashin da ya gabata.Don haka, duk lissafin lambobi na duka nau'ikan tashin hankali an yi su ta amfani da canjin lokaci na 0.02 \(\stackrel{\mathrm{-}}{7}\) don 3 rpm, 0.0208 \(\stackrel{ \mathrm{-} {3}\) 4 rpm.Don wani matakin gyaran da aka bayar, adadin Courant na tantanin halitta koyaushe yana ƙasa da 1.0.
Don bincika dogaro-mesh na samfur, an fara samun sakamako ta hanyar amfani da raga na 2.14M na asali sannan kuma ragamar 2.88M mai ladabi.Ana samun gyare-gyaren grid ta hanyar rage girman tantanin halitta na mahaɗin daga 9 × \({10}^{-3}\) m zuwa 7 × \({10}^{-3}\) m.Don na asali da ingantattun raga na rikice-rikicen nau'ikan nau'ikan guda biyu, an kwatanta matsakaicin ƙimar samfuran saurin gudu a wurare daban-daban a kusa da ruwa.Bambancin kashi tsakanin sakamakon shine 1.73% don ƙirar SST k–ω da 3.51% don ƙirar IDDES.IDDES yana nuna babban bambanci na kashi saboda ƙirar RANS-LES ce ta matasan.An yi la'akari da waɗannan bambance-bambance ba su da mahimmanci, don haka an yi simintin ta amfani da raga na asali tare da abubuwa miliyan 2.14 da lokacin juyawa na 0.5 °.
An yi nazarin sake fasalin sakamakon gwajin ta hanyar yin kowane ɗayan gwaje-gwaje shida a karo na biyu da kwatanta sakamakon.Kwatanta ƙimar saurin gudu a tsakiyar ruwa a cikin jerin gwaje-gwaje guda biyu.Matsakaicin matsakaicin kashi tsakanin ƙungiyoyin gwaji biyu shine 3.1%.Hakanan an sake daidaita tsarin PIV don kowane gwaji.Kwatanta saurin ƙididdigewa na nazari a tsakiyar kowace ruwa tare da saurin PIV a wuri ɗaya.Wannan kwatancen yana nuna bambanci tare da matsakaicin kuskuren kashi 6.5% na ruwa 1.
Kafin a kididdige ma’aunin zamewa, ya zama dole a kimiyance a fahimci ma’anar zamewa a cikin flocculator, wanda ke buqatar nazarin tsarin tafiyar da magudanan ruwa.A bisa ra'ayi, an gina madaidaicin zamewa cikin ƙirar flocculators na filafili don la'akari da saurin ruwan wukake dangane da ruwa.Littattafan sun ba da shawarar cewa wannan saurin ya zama kashi 75% na saurin ruwa, don haka yawancin ƙira suna amfani da ak na 0.25 don lissafin wannan daidaitawa.Wannan yana buƙatar amfani da hanyoyin saurin gudu da aka samo daga gwaje-gwajen PIV don cikakken fahimtar filin saurin gudu da yin nazarin wannan zamewa.Blade 1 ita ce ruwan ciki mafi kusa da shaft, ruwa 3 shine mafi girman ruwa, kuma ruwa 2 shine tsakiyar ruwa.
Matsakaicin saurin kan ruwa 1 yana nuna jujjuyawa kai tsaye a kusa da ruwan.Waɗannan sifofi masu gudana suna fitowa daga wuri a gefen dama na ruwa, tsakanin rotor da ruwa.Duban wurin da akwatin ja mai dige-dige ya nuna a cikin Hoto na 4a, yana da ban sha'awa don gano wani bangare na sake zagayawa a sama da kewayen ruwa.Hannun gani mai gudana yana nuna ɗan gudu zuwa yankin sake zagayawa.Wannan magudanar ruwa yana zuwa daga gefen dama na ruwa a tsayin kusan 6 cm daga ƙarshen ruwan, maiyuwa ne saboda tasirin farar ruwan hannun da ke gaban ruwan, wanda ke bayyane a cikin hoton.Hannun gani mai gudana a rpm 4 yana nuna ɗabi'a da tsari iri ɗaya, a fili tare da mafi girman gudu.
Filin saurin gudu da jadawali na yanzu na ruwan wukake uku a saurin juyawa biyu na 3rpm da 4 rpm.Matsakaicin matsakaicin matsakaicin matsakaicin ruwan wukake guda uku a 3 rpm shine 0.15 m/s, 0.20 m/s da 0.16 m/s bi da bi, kuma matsakaicin matsakaicin matsakaici a 4 rpm shine 0.15 m/s, 0.22 m/s da 0.22 m/ s, bi da bi.a kan zanen gado uku.
An samo wani nau'i na hawan helical tsakanin vanes 1 da 2. Filin vector yana nuna a fili cewa ruwan ruwa yana motsawa sama daga kasan vane 2, kamar yadda aka nuna ta hanyar vector.Kamar yadda aka nuna ta akwatin mai dige-ɗige a cikin siffa 4b, waɗannan ƙwayoyin cuta ba sa hawa sama a tsaye daga saman ruwan, amma suna juya zuwa dama kuma a hankali suna gangarowa.A saman ruwa na 1, an bambanta vectors zuwa ƙasa, waɗanda ke kusanci duka ruwan wukake kuma suna kewaye da su daga magudanar ruwa da aka yi a tsakanin su.An ƙaddara tsarin tafiyar guda ɗaya a duka saurin jujjuyawa tare da girman girman saurin gudu na 4 rpm.
Filin saurin ruwa na ruwa 3 ba ya ba da gudummawa mai mahimmanci daga saurin vector na ruwan da ya gabata yana haɗuwa da magudanar ruwa a ƙarƙashin ruwa 3. Babban magudanar ruwa a ƙarƙashin ruwa na 3 yana faruwa ne saboda yanayin saurin gudu na tsaye yana tashi tare da ruwa.
Za'a iya raba magudanar saurin da ke saman saman ruwa 3 zuwa rukuni uku, kamar yadda aka nuna a hoto na 4c.Saitin farko shine wanda ke gefen dama na ruwa.Tsarin gudana a wannan matsayi yana tsaye zuwa dama da sama (watau zuwa ruwa 2).Rukuni na biyu shine tsakiyar ruwa.Matsakaicin saurin wannan matsayi yana jagorantar kai tsaye, ba tare da wata karkata ba kuma ba tare da juyawa ba.An ƙaddara raguwar ƙimar saurin gudu tare da karuwa a tsayi sama da ƙarshen ruwa.Ga rukuni na uku, wanda yake a gefen hagu na ruwan wukake, ana kai ruwa nan da nan zuwa hagu, watau bangon flocculator.Yawancin magudanar ruwa da ke wakilta da vector vector yana hawa sama, kuma wani ɓangare na kwarara yana tafiya a kwance.
An yi amfani da nau'ikan tashin hankali guda biyu, SST k-ω da IDDES, don gina madaidaitan bayanan bayanan saurin lokaci don 3rpm da 4 rpm a cikin ma'anar tsawon jirgin sama.Kamar yadda aka nuna a cikin hoto na 5, ana samun tsayayyen yanayi ta hanyar samun kamanceceniya tsakanin ma'aunin saurin gudu wanda aka yi ta jujjuyai guda huɗu.Bugu da ƙari, matsakaicin matsakaicin matsakaicin lokaci da aka samar ta hanyar IDDES an nuna su a cikin Fig. 6a, yayin da ma'auni na tsawon lokaci da aka yi ta hanyar SST k - ω an nuna su a cikin siffa 6a.6b ku.
Yin amfani da IDDES da madaidaitan madaukai na saurin lokaci wanda SST k–ω ke samarwa, IDDES yana da mafi girman adadin madaukai masu saurin gudu.
Yi nazarin bayanin martabar saurin da aka ƙirƙira tare da IDDES a 3 rpm kamar yadda aka nuna a Hoto 7. Mai haɗawa yana jujjuya agogon agogo kuma ana tattauna kwararar bisa ga bayanin kula da aka nuna.
A kan fig.7 ana iya ganin cewa a saman ruwa na 3 a cikin I quadrant akwai rabuwa da ruwa, tun da yake ba a ƙuntatawa ba saboda kasancewar rami na sama.A cikin quadrant II ba a lura da rabuwar kwararar ruwa ba, tun da an iyakance kwararar ta gaba ɗaya ta bangon flocculator.A cikin quadrant III, ruwan yana jujjuyawa da ƙaranci ko ƙasa da sauri fiye da na baya.Ruwan da ke cikin quadrant I da II ana matsar da shi (watau juyawa ko turawa) ƙasa ta aikin mahaɗin.Kuma a cikin quadrant III, ruwa yana fitar da ruwan wukake na masu tayar da hankali.A bayyane yake cewa yawan ruwa a wannan wuri yana tsayayya da hannun rigar flocculator da ke gabatowa.Juyin juzu'i a cikin wannan quadrant ya rabu gaba ɗaya.Ga quadrant IV, yawancin iskar da ke sama da vane 3 ana karkata zuwa bangon flocculator kuma a hankali yana rasa girmansa yayin da tsayin ya ƙaru zuwa saman buɗewa.
Bugu da kari, wurin tsakiya ya hada da hadaddun tsarin kwarara wanda ya mamaye murabba'i III da IV, kamar yadda aka nuna ta shudi mai dige ellipses.Wannan yanki mai alamar ba shi da alaƙa da magudanar ruwa a cikin flocculator, saboda ana iya gano motsin motsi.Wannan ya bambanta da quadrants I da II inda akwai bayyanannen rabuwa tsakanin kwararar ciki da cikakken juzu'i.
Kamar yadda aka nuna a cikin fig.6, kwatanta sakamakon IDDES da SST k-ω, babban bambanci tsakanin madaidaicin maɗaukaki shine girman saurin gudu nan da nan a ƙasa da ruwa 3. SST k-ω samfurin ya nuna a fili cewa tsawaita hawan gudu yana gudana ta hanyar ruwa 3. idan aka kwatanta da IDDES.
Ana iya samun wani bambanci a cikin quadrant III.Daga IDDES, kamar yadda aka ambata a baya, an lura da rarrabuwar magudanar ruwa tsakanin hannaye na flocculator.Duk da haka, wannan matsayi yana da tasiri sosai ta hanyar ƙananan gudu daga sasanninta da ciki na farkon ruwa.Daga SST k–ω don wuri ɗaya, layin kwane-kwane suna nuna ingantacciyar gudu idan aka kwatanta da IDDES saboda babu kwararar ruwa daga wasu yankuna.
Ana buƙatar fahimtar ingantacciyar fa'ida ta filayen vector vector da streamlines don ingantaccen fahimtar yanayin gudana da tsari.Ganin cewa kowane ruwa yana da faɗin cm 5, an zaɓi maki masu saurin gudu guda bakwai a fadin faɗin don samar da bayanin martabar saurin wakilci.Bugu da ƙari, ana buƙatar fahimtar ƙididdiga na girman gudu a matsayin aikin tsayi sama da saman ruwa ta hanyar yin ƙirƙira bayanin saurin gudu kai tsaye a kan kowane saman ruwa kuma a kan ci gaba da nisa na 2.5 cm a tsaye har zuwa tsayin 10 cm.Dubi S1, S2 da S3 a cikin adadi don ƙarin bayani.Shafi A. Hoto 8 yana nuna kamanni na rarraba saurin saman kowane ruwa (Y = 0.0) da aka samu ta amfani da gwaje-gwajen PIV da nazarin ANSYS-Fluent ta amfani da IDDES da SST k-ω.Duka nau'ikan lambobi biyu suna ba da damar yin daidaitaccen tsarin tsarin gudana akan saman ruwan wutsiyar ruwa.
Rarraba saurin PIV, IDDES da SST k–ω akan saman ruwa.Ƙimar x-axis tana wakiltar faɗin kowane takarda a cikin millimeters, tare da asalin (0 mm) yana wakiltar gefen hagu na takardar da ƙarshen (50 mm) yana wakiltar gefen dama na takardar.
An gani a fili cewa an nuna saurin rarraba ruwan wukake 2 da 3 a cikin Fig.8 da Fig.8.S2 da S3 a cikin Shafi A suna nuna irin wannan yanayin tare da tsayi, yayin da ruwa 1 yana canzawa da kansa.Siffofin saurin ruwan wukake na 2 da 3 sun zama daidai daidai kuma suna da girman girman guda ɗaya a tsayin 10 cm daga ƙarshen ruwan.Wannan yana nufin cewa kwararar ta zama iri ɗaya a wannan lokacin.Ana ganin wannan a fili daga sakamakon PIV, waɗanda IDDES suka sake bugawa da kyau.A halin yanzu, sakamakon SST k–ω yana nuna wasu bambance-bambance, musamman a 4 rpm.
Yana da mahimmanci a lura cewa ruwa 1 yana riƙe da nau'i ɗaya na bayanin martabar sauri a duk matsayi kuma ba a daidaita shi ba a tsayi, tun da swirl da aka kafa a tsakiyar mahaɗin ya ƙunshi ruwan farko na duk makamai.Hakanan, idan aka kwatanta da IDDES, bayanan bayanan saurin ruwa na PIV 2 da 3 sun nuna ƙimar saurin gudu kaɗan a mafi yawan wurare har sai sun kusan kusan daidai da 10 cm sama da saman ruwa.
Lokacin aikawa: Dec-27-2022