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Ua hoʻāʻo ʻia nā nanofluids covalent a me non-covalent i loko o nā paipu poepoe i hoʻolako ʻia me nā hoʻokomo lipine wili me nā kihi helix o 45 ° a me 90 °.ʻO ka helu Reynolds ʻo 7000 ≤ Re ≤ 17000, ua loiloi ʻia nā waiwai thermophysical ma 308 K. Hoʻoponopono ʻia ke ʻano kino i ka helu me ka hoʻohana ʻana i kahi kumu hoʻohālike turbulent viscosity ʻelua (SST k-omega turbulence).Ua noʻonoʻo ʻia nā manaʻo (0.025 wt.%, 0.05 wt.%, a me 0.1 wt.%) o nā nanofluids ZNP-SDBS@DV a me ZNP-COOH@DV i ka hana.Ua wela na paia o na paipu wiliwili i ka wela mau o 330 K. Eono mau palena i noonooia ma ka ha'awina o keia manawa: ka wela o ka puka, ka huina hoololi wela, ka helu Nusselt awelika, ka helu o ka friction, ka poho pumehana, a me na pae hooioi hana.Ma nā hihia ʻelua (helix angle o 45 ° a me 90 °), ua hōʻike ka ZNP-SDBS@DV nanofluid i nā hiʻohiʻona thermal-hydraulic kiʻekiʻe ma mua o ZNP-COOH@DV, a ua hoʻonui ʻia me ka hoʻonui ʻana i ka hapa nui, no ka laʻana, 0.025 wt., a me 0.05 wt.ʻo 1.19.% a me 1.26 - 0.1 wt.%.Ma nā hihia ʻelua (helix angle 45° a me 90°), nā waiwai o nā ʻano thermodynamic i ka wā e hoʻohana ai iā GNP-COOH@DW he 1.02 no 0.025% wt., 1.05 no 0.05% wt.a me 1.02 no ka 0.1% wt.
ʻO ka mea hoʻololi wela he mea thermodynamic 1 i hoʻohana ʻia e hoʻololi i ka wela i ka wā hoʻoluʻu a me nā hana hoʻomehana.ʻO nā waiwai thermal-hydraulic o ka mea hoʻololi wela e hoʻomaikaʻi i ka coefficient hoʻoili wela a hoʻemi i ke kū'ē o ka wai hana.Ua hoʻomohala ʻia kekahi mau ʻano e hoʻomaikaʻi i ka hoʻoili wela, me nā mea hoʻonui turbulence2,3,4,5,6,7,8,9,10,11 a me nanofluids12,13,14,15.ʻO ka hoʻokomo ʻana i ka lipine wili ʻia kekahi o nā ala kūleʻa loa no ka hoʻomaikaʻi ʻana i ka hoʻoili wela i nā mea hoʻololi wela ma muli o ka maʻalahi o ka mālama ʻana a me ke kumu kūʻai haʻahaʻa7,16.
I loko o nā haʻawina hoʻokolohua a me ka helu helu, ua aʻo ʻia nā waiwai hydrothermal o nā hui ʻana o nā nanofluids a me nā mea hoʻololi wela me nā hoʻokomo lipine wili.Ma kahi hana hoʻokolohua, ua aʻo ʻia nā waiwai hydrothermal o ʻekolu nanofluids metala like ʻole (Ag@DW, Fe@DW a me Cu@DW) i loko o kahi mea hoʻololi wela wili (STT)17.Ke hoʻohālikelike ʻia me ka paipu kumu, hoʻomaikaʻi ʻia ka coefficient hoʻoili wela o STT e 11% a me 67%.ʻO ka hoʻolālā SST ka mea maikaʻi loa mai kahi manaʻo hoʻokele waiwai e pili ana i ka pono me ka palena α = β = 0.33.Eia kekahi, he 18.2% ka piʻi ʻana o n i ʻike ʻia me Ag@DW, ʻoiai ʻo 8.5% wale nō ka piʻi nui ʻana o ka poho puʻe.Ua aʻo ʻia nā kaʻina hana kino o ka hoʻoili wela a me ka nalo puʻe i loko o nā paipu concentric me nā turbulators wili ʻole ʻia me ka hoʻohana ʻana i nā kahe ʻino o Al2O3@DW nanofluid me ka convection ikaika.ʻO ka helu helu Nusselt kiʻekiʻe loa (Nuavg) a me ka poho puʻe e ʻike ʻia ma Re = 20,000 i ka manawa o ka pitch coil = 25 mm a me Al2O3@DW nanofluid 1.6 vol.%.Ua mālama ʻia nā haʻawina hoʻokolohua no ke aʻo ʻana i ka hoʻololi wela a me nā hiʻohiʻona o ka nalo ʻana o ka graphene oxide nanofluids (GO@DW) e kahe ana ma waena o nā paipu pōʻai me nā mea hoʻokomo WC.Ua hōʻike nā hopena i ka 0.12 vol% -GO@DW i hoʻonui i ka convective heat transfer coefficient ma kahi o 77%.Ma kekahi noiʻi hoʻokolohua ʻē aʻe, ua hoʻomohala ʻia nā nanofluids (TiO2@DW) e aʻo i nā hiʻohiʻona thermal-hydraulic o nā paipu dimpled i hoʻokomo ʻia me nā mea hoʻokomo lipine wili20.Ua loaʻa ka ikaika hydrothermal o 1.258 me ka hoʻohana ʻana i ka 0.15 vol% -TiO2@DW i hoʻokomo ʻia i loko o 45 ° inclined shafts me ka twist factor o 3.0.E noʻonoʻo nā ʻano hoʻohālike hoʻohālike ʻelua-phase a me ʻelua-phase (hybrid) i ke kahe a me ka hoʻoili wela o CuO@DW nanofluids ma nā ʻano paʻa like ʻole (1-4% vol.%)21.ʻO ka ʻoi loa o ka wela wela o ka paipu i hoʻokomo ʻia me hoʻokahi lipine wili ʻia he 2.18, a ʻo kahi paipu i hoʻokomo ʻia me ʻelua mau lipine wili ma lalo o nā kūlana like ʻo 2.04 (hoʻohālike ʻelua-phase, Re = 36,000 a me 4 vol.%).Ua aʻo ʻia ke kahe ʻana o ka carboxymethyl cellulose (CMC) a me ka copper oxide (CuO) i loko o nā paipu nui a me nā paipu me nā mea hoʻokomo wili.Hōʻike ʻo Nuavg i ka holomua o 16.1% (no ka pipeline nui) a me 60% (no ka pipeline coiled me ka ratio o (H/D = 5)).ʻO ka mea maʻamau, ʻoi aku ka hopena o ka ratio wili-a-ribbon haʻahaʻa i ka coefficient kiʻekiʻe o ka friction.I loko o kahi hoʻokolohua hoʻokolohua, ua aʻo ʻia ka hopena o nā paipu me kahi lipine wili (TT) a me nā coils (VC) ma nā waiwai o ka hoʻololi ʻana i ka wela a me ka coefficient friction me ka CuO@DW nanofluids.Ke hoʻohana nei i ka 0.3 vol.%-CuO@DW ma Re = 20,000 hiki ke hoʻonui i ka hoʻoili wela ma ka paipu VK-2 i ka waiwai nui o 44.45%.Eia kekahi, i ka wā e hoʻohana ai i kahi kaula wili a me kahi hoʻokomo coil ma lalo o nā kūlana palena like, piʻi ka coefficient o friction e nā kumu o 1.17 a me 1.19 i hoʻohālikelike ʻia me DW.Ma keʻano laulā, ʻoi aku ka maikaʻi o ka wela o nā nanofluids i hoʻokomo ʻia i loko o nā coils ma mua o nā nanofluids i hoʻokomo ʻia i loko o nā uea stranded.Ua aʻo ʻia ke ʻano volumetric o kahi kahe nanofluid (MWCNT@DW) i loko o kahi paipu ākea i hoʻokomo ʻia i loko o kahi uwea spiral.ʻO nā palena hana wela he> 1 no nā hihia āpau, e hōʻike ana i ka hui pū ʻana o nā nanofluidics me ka hoʻokomo coil e hoʻomaikaʻi i ka hoʻoili wela me ka ʻole o ka pau ʻana o ka mana pamu.Abstract—Ua aʻo ʻia nā hiʻohiʻona hydrothermal o kahi mea hoʻololi wela ʻelua-paipu me nā mea hoʻokomo like ʻole i hana ʻia me kahi lipine V-shaped wili-wili i hoʻololi ʻia (VcTT) i hoʻopaʻa ʻia ma lalo o nā kūlana o ke kahe ʻino o ka nanofluid Al2O3 + TiO2@DW.Ke hoʻohālikelike ʻia me DW i nā paipu kumu, loaʻa iā Nuavg ka hoʻomaikaʻi nui ʻana o 132% a me kahi koena friction a hiki i 55%.Eia hou, ua kūkākūkā ka ikehu o ka Al2O3 + TiO2@DW nanocomposite i loko o ka lua-paipu heat exchanger26.Ma kā lākou noiʻi ʻana, ʻike lākou i ka hoʻohana ʻana o Al2O3 + TiO2@DW a me TT i hoʻomaikaʻi maikaʻi i ka exergy pono i hoʻohālikelike ʻia me DW.Ma concentric tubular heat exchangers me VcTT turbulators, Singh a me Sarkar27 hoʻohana i nā mea hoʻololi pae (PCM), hoʻopuehu ʻia hoʻokahi / nanocomposite nanofluids (Al2O3@DW me PCM a me Al2O3 + PCM).Ua hōʻike lākou i ka piʻi ʻana o ka wela a me ka poho puʻe i ka emi ʻana o ka coefficient twist a me ka piʻi ʻana o ka nanoparticle.Hiki ke hā'awi i ka ho'ololi wela a me ka poho pu'e i ka nui V-notch hohonu a i 'ole ka laulā li'ili'i.Eia kekahi, ua hoʻohana ʻia ka graphene-platinum (Gr-Pt) no ka noiʻi ʻana i ka wela, friction, a me ka helu o ka entropy generation rate ma nā paipu me nā mea hoʻokomo 2-TT28.Ua hōʻike kā lākou noiʻi ʻana i kahi pākēneka liʻiliʻi o (Gr-Pt) i hōʻemi nui i ka hana entropy wela ke hoʻohālikelike ʻia me kahi hoʻomohala entropy frictional kiʻekiʻe.Hiki ke no'ono'o 'ia ka hui 'ana o Al2O3@MgO nanofluids a me ka conical WC, no ka mea, hiki i ka ratio ho'onui (h/Δp) ke ho'omaika'i i ka hana hydrothermal o ka mea ho'ololi wela 2-tube 29.Hoʻohana ʻia kahi kŘkohu helu no ka loiloi ʻana i ka hoʻōla ʻana i ka ikehu a me ka hana kaiapuni o nā mea hoʻololi wela me nā ʻano nanofluids hybrid ʻekolu ʻāpana (THNF) (Al2O3 + graphene + MWCNT) i hoʻokuʻu ʻia ma DW30.Ma muli o kāna Performance Evaluation Criteria (PEC) ma ka laulā o 1.42-2.35, pono kahi hui o Depressed Twisted Turbulizer Insert (DTTI) a me (Al2O3 + Graphene + MWCNT).
A hiki i kēia manawa, ua uku ʻia ka nānā liʻiliʻi i ka hana o ka covalent a me ka non-covalent functionalization i ka kahe hydrodynamic i nā wai wela.ʻO ke kumu kikoʻī o kēia haʻawina ʻo ia ka hoʻohālikelike ʻana i nā hiʻohiʻona thermal-hydraulic o nā nanofluids (ZNP-SDBS@DV) a me (ZNP-COOH@DV) i nā hoʻokomo lipine wili me nā kihi helix o 45 ° a me 90 °.Ua ana 'ia na waiwai thermophysical ma Tin = 308 K. Ma keia hihia, ua malamaia ekolu hakina nui ma ka hana hoohalike, e like me (0.025 wt.%, 0.05 wt.% a me 0.1 wt.%).Hoʻohana ʻia ka hoʻololi ʻana i ke koʻikoʻi shear i ke kumu hoʻohālike 3D turbulent flow (SST k-ω) e hoʻoponopono i nā ʻano thermal-hydraulic.No laila, hāʻawi nui kēia haʻawina i ke aʻo ʻana i nā waiwai maikaʻi (wela wela) a me nā waiwai maikaʻi ʻole (ke kaomi ʻana i ka friction), e hōʻike ana i nā ʻano thermal-hydraulic a me ka hoʻonui ʻana i nā wai hana maoli i loko o ia ʻōnaehana ʻenekinia.
ʻO ka hoʻonohonoho kumu he paipu maʻemaʻe (L = 900 mm a me Dh = 20 mm).Hoʻokomo ʻia nā ana lipine wili ʻia (lōʻihi = 20 mm, mānoanoa = 0.5 mm, profile = 30 mm).Ma keia hihia, he 20 mm, 0.5 mm, a me 30 mm ka loa, ka laula, a me ka hahau o ka pilipili.Hoʻopili ʻia nā lipine wili ʻia ma 45° a me 90°.ʻO nā wai hana like ʻole e like me DW, non-covalent nanofluids (GNF-SDBS@DW) a me covalent nanofluids (GNF-COOH@DW) ma Tin = 308 K, ʻekolu mau ʻano nuipaʻa like ʻole a me nā helu Reynolds like ʻole.Ua hana ʻia nā hoʻokolohua i loko o ka mea hoʻololi wela.Ua wela ka paia o waho o ka paipu spiral ma kahi wela mau o 330 K e ho'āʻo ai i nā ʻāpana no ka hoʻomaikaʻi ʻana i ka hoʻoili wela.
Ma ka fig.Hōʻike ʻia ʻo 1 i kahi paipu hoʻokomo lipine wili me nā kūlana palena kūpono a me ka ʻāpana meshed.E like me ka mea i ʻōlelo mua ʻia, pili nā kūlana palena o ka wikiwiki a me ke kaomi i nā ʻāpana inlet a me waho o ka helix.Ma kahi mahana wela mau, hoʻokau ʻia kahi kūlana non-slip ma ka paia paipu.Ke hoʻohana nei ka hoʻohālikelike helu i kēia manawa i kahi hoʻonā kaomi.Ma ka manawa like, hoʻohana ʻia kahi papahana (ANSYS FLUENT 2020R1) e hoʻololi i ka hoʻohālikelike ʻokoʻa hapa (PDE) i loko o kahi ʻōnaehana o nā hoʻohālikelike algebraic me ka hoʻohana ʻana i ke ʻano leo palena (FMM).ʻO ke ʻano hana SIMPLE ka lua o ka papa (semi-implicit method for sequential pressure-dependent equations) pili i ka velocity-pressure.Pono e hoʻomaopopo ʻia ʻo ka hoʻohui ʻana o nā koena no ka nuipaʻa, ka manawa, a me ka ikehu e emi iho ma mua o 103 a me 106.
p Diagram of physical and computational domains: (a) helix angle 90°, (b) helix angle 45°, (c) ole helical blade.
Hoʻohana ʻia kahi kumu hoʻohālike homogeneous e wehewehe i nā waiwai o nā nanofluids.Ma ka hoʻokomoʻana i nā nanomaterials i loko o ka wai kumu (DW), ua hoʻokumuʻia kahi wai mau me nā mea wela maikaʻi loa.Ma keia manao, ua like ka waiwai o ka wela a me ka velocity o ka wai kumu a me ka nanomaterial.Ma muli o nā manaʻo a me nā manaʻo i luna, hana maikaʻi ka kahe hoʻokahi-phase i kēia haʻawina.Ua hōʻike kekahi mau haʻawina i ka maikaʻi a me ka hoʻohana ʻana i nā ʻenehana hoʻokahi-phase no ke kahe nanofluidic31,32.
Pono ke kahe o nā nanofluids i Newtonian turbulent, incompressible and stationary.ʻAʻole pili ka hana hoʻoemi a me ka hoʻomehana viscous i kēia haʻawina.Eia kekahi, ʻaʻole i manaʻo ʻia ka mānoanoa o nā paia o loko a me waho o ka paipu.No laila, hiki ke hōʻike ʻia ka nuipa, ka manawa, a me ka mālama ʻana i ka ikehu e wehewehe i ke kumu hoʻohālike e like me kēia:
kahi \(\overrightarrow{V}\) ka mean velocity vector, Keff = K + Kt ka hana wela kūpono o ka covalent a me ka noncovalent nanofluids, a o ε ka ho'ohehe'e ikehu.ʻO nā waiwai thermophysical maikaʻi o nā nanofluids, me ka density (ρ), viscosity (μ), ka nui o ka wela (Cp) a me ka conductivity thermal (k), i hōʻike ʻia ma ka papa, ua ana ʻia i ka wā o kahi haʻawina hoʻokolohua ma kahi mahana o 308 K1 ke hoʻohana ʻia. i kēia mau simulators.
Ua hoʻokō ʻia nā hoʻohālikelike helu o ke kahe nanofluid turbulent i nā paipu maʻamau a me TT ma nā helu Reynolds 7000 ≤ Re ≤ 17000. Ua kālailai ʻia kēia mau hoʻohālikelike a me nā coefficients hoʻoili wela convective me ka hoʻohana ʻana i ke kumu hoʻohālike o Mentor's κ-ω turbulence model of shear stress transfer (SST) awelika ma luna o ka Reynolds turbulence. kumu hoʻohālike Navier-Stokes, hoʻohana mau ʻia i ka noiʻi aerodynamic.Eia kekahi, hana ke kumu hoʻohālike me ka hana ʻole o ka pā a pololei kokoke i nā paia 35,36.(SST) κ-ω mau hoohalike hooponopono o ke kumu hoohaunaele penei:
ma kahi o \(S\) ka waiwai o ka laiki pili, a me \(y\) ka mamao i ka ili pili.I kēia manawa, \({\alpha}_{1}\), \({\alpha}_{2}\), \({\beta}_{1}\), \({\beta}_{ 2 }\), \({\beta}^{*}\), \({\sigma}_{{k}_{1}}\), \({\sigma}_{{k}_{ 2 }}\), \({\sigma}_{{\omega}_{1}}\) a me \({\sigma}_{{\omega}_{2}}\) hōʻike i nā mea hoʻohālikelike a pau.ʻO F1 a me F2 nā hana hui.'Ōlelo Aʻo: F1 = 1 ma ka papa palena, 0 ma ka kahe e hiki mai ana.
Hoʻohana ʻia nā ʻāpana loiloi hana no ke aʻo ʻana i ka hoʻoili wela convective kūpilikiʻi, ke kahe nanofluid covalent a me ka non-covalent, no ka laʻana31:
Ma kēia pōʻaiapili, hoʻohana ʻia (\(\rho\)), (\(v\)), (\({D}_{h}\)) a me (\(\mu\)) no ka mānoanoa, ka wikiwiki o ka wai. , hydraulic anawaena a me dynamic viscosity.(\({C}_{p}\, \mathrm{u}\, k\)) – ka mana wela kiko'ī a me ka hana wela o ka wai kahe.Eia kekahi, (\(\dot{m}\)) pili i ke kahe nui, a (\({T}_{out}-{T}_{in}\)) e pili ana i ka ʻokoʻa wela o loko a me waho.(NFs) pili i ka covalent, non-covalent nanofluids, a (DW) pili i ka wai distilled (waiwai kumu).\({A}_{s} = \pi DL\), \({\ overline{T}}_{f}=\frac{\hema({T}_{out}-{T}_{in }\'ākau)}{2}\) a me \({\ overline{T}}_{w}=\sum \frac{{T}_{w}}{n}\).
ʻO nā waiwai thermophysical o ka wai kumu (DW), non-covalent nanofluid (GNF-SDBS@DW), a me covalent nanofluid (GNF-COOH@DW) i lawe ʻia mai nā palapala i paʻi ʻia (nā haʻawina hoʻokolohua), Sn = 308 K, e like me hōʻike ʻia ma ka Papa 134. Ma kahi maʻamau I kahi hoʻokolohua e loaʻa ai kahi nanofluid non-covalent (GNP-SDBS@DW) me nā pākēneka nui i ʻike ʻia, ua kaupaona mua ʻia kekahi mau grams o nā GNP mua ma ke koena kikohoʻe.ʻO ka lakio paona o SDBS/GNP maoli (0.5:1) paona ma DW.I kēia hihia, ua hoʻohui ʻia nā nanofluids covalent (COOH-GNP@DW) ma ka hoʻohui ʻana i nā pūʻulu carboxyl i ka ʻili o GNP me ka hoʻohana ʻana i kahi mea ʻakika ikaika me ka ratio leo (1:3) o HNO3 a me H2SO4.Ua hoʻokuʻu ʻia nā nanofluids covalent a me non-covalent i DW ma ʻekolu mau pākēneka kaumaha like ʻole e like me 0.025 wt%, 0.05 wt%.a me 0.1% o ka nuipa.
Ua hana ʻia nā hoʻāʻo kūʻokoʻa mesh i ʻehā mau kikowaena helu helu ʻokoʻa e hōʻoia ai ʻaʻole pili ka nui mesh i ka simulation.I ka hihia o ka paipu torsion 45 °, ʻo ka helu o nā ʻāpana me ka nui o ka ʻāpana 1.75 mm he 249,033, ʻo ka helu o nā ʻāpana me ka nui o ka ʻāpana 2 mm he 307,969, ʻo ka helu o nā ʻāpana me ka nui o ka ʻāpana 2.25 mm he 421,406, a me ka helu o nā ʻāpana. me ka nui o ka wae 2 .5 mm 564 940 pakahi.Eia kekahi, ma ka laʻana o kahi paipu wili 90 °, ʻo ka helu o nā mea me ka nui o ka element 1.75 mm he 245,531, ʻo ka helu o nā mea me ka nui element 2 mm he 311,584, ʻo ka helu o nā mea me ka nui element 2.25 mm. 422,708, a ʻo ka helu o nā mea me ka nui o ka element 2.5 mm ʻo ia ka 573,826.Piʻi ka pololei o ka heluhelu waiwai wela e like me (Tout, htc, a me Nuavg) i ka emi ʻana o nā mea.I ka manawa like, ua hōʻike ʻia ka pololei o nā waiwai o ka friction coefficient a me ka hāʻule kaomi i kahi ʻano ʻokoʻa loa (Fig. 2).Ua hoʻohana ʻia ʻo Grid (2) ma ke ʻano o ka mākia nui e loiloi i nā ʻano thermal-hydraulic i ka hihia i hoʻohālikelike ʻia.
Ke ho'āʻo nei i ka hoʻololi ʻana i ka wela a me ka hoʻohaʻahaʻa ʻana i ka hana me ka mesh me ka hoʻohana ʻana i nā paipu DW i wili ʻia ma 45° a me 90°.
Ua hōʻoia ʻia nā hopena helu i kēia manawa no ka hoʻololi ʻana i ka wela a me ka helu friction me ka hoʻohana ʻana i nā correlations empirical kaulana a me nā hoohalike like me Dittus-Belter, Petukhov, Gnelinsky, Notter-Rouse a me Blasius.Ua hana ʻia ka hoʻohālikelike ma lalo o ke kūlana 7000≤Re≤17000.Wahi a ka fig.3, ʻo ka awelika a me ka nui o nā hewa ma waena o nā hopena simulation a me ka hoʻohālikelike hoʻoili wela he 4.050 a me 5.490% (Dittus-Belter), 9.736 a me 11.33% (Petukhov), 4.007 a me 7.483% (Gnelinsky), a me 3.883% a me 4.93% Nott-Belter).Rose).I kēia hihia, ʻo ka awelika a me ka hapa nui ma waena o nā hopena simulation a me ka hoʻohālikelike hoʻohālikelike friction he 7.346% a me 8.039% (Blasius) a me 8.117% a me 9.002% (Petukhov).
Hoʻololi wela a me nā waiwai hydrodynamic o DW ma nā helu Reynolds like ʻole me ka hoʻohana ʻana i nā helu helu a me nā hoʻoponopono empirical.
Kūkākūkā kēia ʻāpana i nā waiwai wela o ka non-covalent (LNP-SDBS) a me ka covalent (LNP-COOH) aqueous nanofluids ma ʻekolu mau hakina nuipaʻa like ʻole a me nā helu Reynolds e like me nā awelika e pili ana i ka wai kumu (DW).ʻElua geometries o nā mea hoʻololi wela kāʻei wili (helix angle 45 ° a me 90 °) i kūkākūkā ʻia no 7000 ≤ Re ≤ 17000. Ma ka fig.Hōʻike ka 4 i ka awelika wela ma ka puka ʻana o ka nanofluid i loko o ka wai kumu (DW) (\(\frac{{{T}_{out}}_{NFs}}{{{T}_{out}}_{ DW } } \) ) ma (0.025% wt., 0.05% wt. a me 0.1% wt.).(\(\frac{{{T}_{out}}_{NFs}}{{{T}_{out}}_{DW}}\)) emi mau ma lalo o 1, 'o ia ho'i, 'o ka wela o ka puka. he non-covalent (VNP-SDBS) a me ka covalent (VNP-COOH) nanofluids ma lalo o ka wela ma ka puka o ka wai kumu.ʻO nā haʻahaʻa haʻahaʻa a kiʻekiʻe loa he 0.1 wt% -COOH@GNPs a me 0.1 wt% -SDBS@GNPs, kēlā me kēia.ʻO kēia hanana ma muli o ka piʻi ʻana o ka helu Reynolds ma kahi hakina paʻa mau, e alakaʻi ana i ka hoʻololi ʻana i nā waiwai o ka nanofluid (ʻo ia hoʻi, density a dynamic viscosity).
Hōʻike nā kiʻi 5 a me 6 i nā hiʻohiʻona hoʻololi wela o ka nanofluid i ka wai kumu (DW) ma (0.025 wt.%, 0.05 wt.% a me 0.1 wt.%).ʻOi aku ka nui o nā waiwai hoʻoili wela ma mua o 1, ʻo ia hoʻi, ua hoʻonui ʻia nā waiwai hoʻoili wela o non-covalent (LNP-SDBS) a me covalent (LNP-COOH) nanofluids i ka hoʻohālikelike ʻana i ka wai kumu.0.1 wt%-COOH@GNPs a me 0.1 wt%-SDBS@GNPs i loaʻa ka loaʻa haʻahaʻa a me ke kiʻekiʻe loa, kēlā me kēia.Ke piʻi aʻe ka helu Reynolds ma muli o ka hui ʻana o ka wai a me ka haunaele i ka paipu 1, e hoʻomaikaʻi ka hana hoʻoili wela.Hiki i nā wai ma nā āpau liʻiliʻi i nā velocities kiʻekiʻe, e loaʻa ana i kahi ʻāpana ʻoi aku ka māmā o ka velocity/wela palena, e hoʻonui ai i ka wikiwiki o ka hoʻoili wela.Hiki i ka hoʻohui ʻana i nā nanoparticles i ka wai kumu ke loaʻa nā hopena maikaʻi a maikaʻi ʻole.ʻO nā hopena maikaʻi e pili ana i ka hoʻonui ʻia ʻana o ka nanoparticle collisions, nā koi hoʻoili wai wela maikaʻi, a me ka hoʻonui ʻana i ka wela.
Heat transfer coefficient of nanofluid to base fluid ma muli o ka helu Reynolds no 45° a me 90° paipu.
I ka manawa like, he hopena maikaʻi ʻole ka hoʻonui ʻana i ka viscosity dynamic o ka nanofluid, e hoʻemi ana i ka neʻe o ka nanofluid, a laila e hoʻemi ana i ka awelika helu Nusselt (Nuavg).ʻO ka piʻi ʻana o ka thermal conductivity o nā nanofluids (ZNP-SDBS@DW) a me (ZNP-COOH@DW) pono ma muli o ka neʻe Brownian a me ka microconvection o nā nanoparticles graphene i hoʻokuʻu ʻia ma DW37.ʻOi aku ka kiʻekiʻe o ka conductivity thermal o ka nanofluid (ZNP-COOH@DV) ma mua o ka nanofluid (ZNP-SDBS@DV) a me ka wai hoʻoheheʻe.ʻO ka hoʻohui ʻana i nā nanomaterial hou aʻe i ka wai kumu e hoʻonui i ko lākou conductivity wela (Papa 1)38.
Hōʻike ka Figure 7 i ke koena awelika o ka friction o nā nanofluids me ka wai kumu (DW) (f(NFs)/f(DW)) ma ka pākēneka nui (0.025%, 0.05% a me 0.1%).ʻO ka awelika friction coefficient he mau ≈1, ʻo ia hoʻi, ʻo ka non-covalent (GNF-SDBS@DW) a me ka covalent (GNF-COOH@DW) nanofluids i like ka friction coefficient me ka wai kumu.ʻO ka mea hoʻololi wela me ka liʻiliʻi o ka lumi e hoʻonui i ke keʻe kahe a hoʻonui i ka friction1.ʻO ke kumu, piʻi iki ka coefficient o ka friction me ka hoʻonui ʻana i ka hapa nui o ka nanofluid.ʻO nā poho frictional kiʻekiʻe ma muli o ka piʻi ʻana o ka viscosity dynamic o ka nanofluid a me ka hoʻonui ʻana i ke koʻikoʻi shear ma luna o ka ʻili me ka hapa nui o ka nanographene i loko o ka wai kumu.Hōʻike ka papa (1) i ke kiʻekiʻe o ka viscosity ikaika o ka nanofluid (ZNP-SDBS@DV) ma mua o ka nanofluid (ZNP-COOH@DV) ma ka pākēneka kaumaha like, e pili ana me ka hoʻohui ʻana i nā hopena ili.nā mea hana ikaika ma kahi nanofluid non-covalent.
Ma ka fig.Hōʻike ka 8 i ka nanofluid i hoʻohālikelike ʻia me ka wai kumu (DW) (\(\frac{{\Delta P}_{NFs}}{{\Delta P}_{DW}}\)) ma (0.025%, 0.05% a me 0.1% ).ʻO ka non-covalent (GNPs-SDBS@DW) nanofluid i hōʻike i kahi kiʻekiʻe awelika puʻe poho, a me ka piʻi ʻana o ka pākēneka nui i 2.04% no 0.025% wt., 2.46% no 0.05% wt.a me 3.44% no ka 0.1% wt.me ka hoʻonui ʻana i ka hihia (helix angle 45° a me 90°).I kēia manawa, ua hōʻike ka nanofluid (GNPs-COOH@DW) i kahi haʻahaʻa haʻahaʻa haʻahaʻa haʻahaʻa, e piʻi ana mai 1.31% ma 0.025% wt.a hiki i ka 1.65% ma ka 0.05% wt.ʻO ka poho puʻe maʻamau o 0.05 wt.%-COOH@NP a me 0.1 wt.%-COOH@NP he 1.65%.E like me ka mea i ʻike ʻia, piʻi ka hāʻule o ke kaomi me ka hoʻonui ʻana i ka helu Re i nā hihia āpau.Hōʻike ʻia ka hoʻonui ʻana o ke kaomi ma nā koina Re kiʻekiʻe e ka hilinaʻi pololei ʻana i ka kahe o ka leo.No laila, ʻoi aku ka helu Re kiʻekiʻe i loko o ka paipu e alakaʻi i kahi hāʻule o ke kaomi kiʻekiʻe, e koi ana i ka hoʻonui ʻana i ka mana pamu39,40.Eia kekahi, ʻoi aku ka kiʻekiʻe o nā poho puʻe ma muli o ka ʻoi aku o ka ikaika o nā eddies a me ka haunaele i hana ʻia e ka ʻāpana ʻili nui, e hoʻonui ai i ka launa pū ʻana o nā puʻe a me nā ikaika inertia i ka papa palena1.
Ma keʻano laulā, hōʻike ʻia nā koina loiloi hana (PEC) no ka non-covalent (VNP-SDBS@DW) a me ka covalent (VNP-COOH@DW) nanofluids ma Fig.9. Ua hōʻike ʻo Nanofluid (ZNP-SDBS@DV) i nā waiwai PEC kiʻekiʻe ma mua o (ZNP-COOH@DV) ma nā hihia ʻelua (helix angle 45 ° a me 90 °) a ua hoʻomaikaʻi ʻia ma ka hoʻonui ʻana i ka hakina nuipa, no ka laʻana, 0.025 wt.%.he 1.17, 0.05 wt.% he 1.19 a he 0.1 wt.% he 1.26.I kēia manawa, ʻo nā waiwai PEC e hoʻohana ana i nā nanofluids (GNPs-COOH@DW) he 1.02 no 0.025 wt%, 1.05 no 0.05 wt%, 1.05 no 0.1 wt%.i nā hihia ʻelua (helix angle 45° a me 90°).1.02.E like me ke kānāwai, me ka hoʻonui ʻana i ka helu Reynolds, e emi nui ana ka thermal-hydraulic efficiency.Ke piʻi aʻe nei ka helu Reynolds, pili pū ʻia ka hoʻemi ʻana i ka coefficient thermal-hydraulic efficiency me ka piʻi ʻana o (NuNFs/NuDW) a me ka emi ʻana o (fNFs/fDW).
ʻO nā waiwai hydrothermal o nā nanofluids e pili ana i nā wai kumu ma muli o nā helu Reynolds no nā paipu me nā kihi 45° a me 90°.
Kūkākūkā kēia ʻāpana i nā mea wela o ka wai (DW), non-covalent (VNP-SDBS@DW), a me covalent (VNP-COOH@DW) nanofluids ma ʻekolu mau ʻano nuipaʻa like ʻole a me nā helu Reynolds.Ua noʻonoʻo ʻia ʻelua mau geometries hoʻololi wela kāʻei i loko o ka laulā 7000 ≤ Re ≤ 17000 e pili ana i nā paipu maʻamau (helix angles 45 ° a me 90 °) e loiloi i ka hana thermal-hydraulic awelika.Ma ka fig.Hōʻike ka 10 i ka wela o ka wai a me nā nanofluids ma ka puka puka ma ke ʻano he awelika e hoʻohana ana (helix angle 45° a me 90°) no kahi paipu maʻamau (\(\frac{{{T}_{out}}_{Twisted}}{{ {T} __ {ma waho}}_{Maʻamau}}\)).Non-covalent (GNP-SDBS@DW) a me covalent (GNP-COOH@DW) nanofluids he ekolu mau hakina kaumaha like ole 0.025 wt%, 0.05 wt% a me 0.1 wt%.E like me ka hoike ana ma ka fig.11, ka waiwai awelika o ka wela puka (\(\frac{{{T}_{out}}_{Twisted}}{{{T}_{out}}_{Plain}}\)) > 1, e hōʻike ana (45 ° a me 90 ° helix angle) ʻoi aku ka nui o ka mahana ma ka puka o ka mea hoʻololi wela ma mua o ka paipu maʻamau, ma muli o ka ʻoi aku ka nui o ka haunaele a me ka hui ʻana o ka wai.Eia kekahi, ua emi ka mahana ma ka puka o DW, non-covalent a me covalent nanofluids me ka hoʻonui ʻana i ka helu Reynolds.ʻO ka wai kumu (DW) ka wela kiʻekiʻe loa o ka puka.I kēia manawa, pili ka waiwai haʻahaʻa i ka 0.1 wt% -SDBS@GNPs.Non-covalent (GNPs-SDBS@DW) nanofluids i hōʻike i ka haʻahaʻa haʻahaʻa puka makani hoʻohālikelike me covalent (GNPs-COOH@DW) nanofluids.Ma muli o ka hui pū ʻana o ka lipine wili i ka pā kahe, hiki ke maʻalahi ke kahe wela o ka pā kokoke i ka wai, e hoʻonui ai i ka wela holoʻokoʻa.ʻO ka lakene wili-a-tape haʻahaʻa e loaʻa ai ka maikaʻi o ke komo ʻana a no laila ʻoi aku ka maikaʻi o ka hoʻoili wela.Ma kekahiʻaoʻao, hiki keʻikeʻia e mālama ka lipine i'ōwiliʻia i kahi mahana haʻahaʻa e pili ana i ka paia, aʻo ia ka mea e hoʻonui ai i ka Nuavg.No nā hoʻokomo lipine wili, hōʻike ka waiwai Nuavg i ʻoi aku ka maikaʻi o ka hoʻoili wela convective i loko o ka paipu22.Ma muli o ka hoʻonui ʻia ʻana o ke ala kahe a me ka hui ʻana a me ka haunaele, piʻi ka manawa noho, ka hopena o ka piʻi ʻana o ka wela o ka wai ma ka puka puka41.
Nā helu Reynolds o nā nanofluids like ʻole e pili ana i ka mahana puka o nā paipu maʻamau (45° a me 90° nā kihi helix).
Heat transfer coefficients (45° a me 90° helix angle) me nā helu Reynolds no nā nanofluids like ʻole i hoʻohālikelike ʻia me nā paipu maʻamau.
ʻO ke ʻano nui o ka hoʻololi ʻana i ka wela o ka lipine i hoʻonui ʻia e like me kēia: 1. ʻO ka hoʻemi ʻana i ke anawaena hydraulic o ka paipu hoʻololi wela e alakaʻi i ka piʻi ʻana o ka wikiwiki o ka kahe a me ka curvature, ʻo ia ka mea e hoʻonui ai i ke koʻikoʻi shear ma ka paia a paipai i ka neʻe lua.2. Ma muli o ka paʻa ʻana o ka lipine wiliwili, piʻi ka wikiwiki ma ka pā paipu, a emi ka mānoanoa o ka papa palena.3. ʻO ke kahe ʻana ma hope o ke kāʻei wili e alakaʻi i ka piʻi ʻana o ka wikiwiki.4. Hoʻomaikaʻi nā vortic i hoʻoulu ʻia i ka hui ʻana o ka wai ma waena o nā ʻāpana waena a kokoke i ka pā o ke kahe42.Ma ka fig.11 a fig.Hōʻike ʻo 12 i nā waiwai hoʻoili wela o DW a me nā nanofluids, no ka laʻana (heat transfer coefficient a me ka awelika helu Nusselt) ma ke ʻano he awelika me ka hoʻohana ʻana i nā paipu hoʻokomo lipine wili i hoʻohālikelike ʻia me nā paipu maʻamau.Non-covalent (GNP-SDBS@DW) a me covalent (GNP-COOH@DW) nanofluids he ekolu mau hakina kaumaha like ole 0.025 wt%, 0.05 wt% a me 0.1 wt%.Ma nā mea hoʻololi wela ʻelua (45° a me 90° helix angle) ʻo ka awelika o ka hana hoʻoili wela he>1, e hōʻike ana i ka hoʻomaikaʻi ʻana i ka coefficient hoʻoili wela a me ka helu Nusselt awelika me nā paipu wili i hoʻohālikelike ʻia me nā paipu maʻamau.Non-covalent (GNPs-SDBS@DW) nanofluids hōʻike kiʻekiʻe awelika hoʻololi wela ma mua o covalent (GNPs-COOH@DW) nanofluids.Ma Re = 900, ʻo ka 0.1 wt% ka hoʻomaikaʻi ʻana i ka hana hoʻoili wela -SDBS@GNPs no nā mea hoʻololi wela ʻelua (45 ° a me 90 ° helix angle) ka mea kiʻekiʻe loa me ka waiwai o 1.90.'O ia ho'i, 'oi aku ka ko'iko'i o ka hopena TP like 'ole ma ka ha'aha'a ha'aha'a o ka wai (helu Reynolds)43 a me ka pi'i 'ana o ka turbulence.Ma muli o ka hoʻokomo ʻia ʻana o nā vortices he nui, ʻoi aku ka kiʻekiʻe o ka helu hoʻoili wela a me ka helu Nusselt awelika o nā paipu TT ma mua o nā paipu maʻamau, e hopena i kahi papa palena ʻoi aku ka lahilahi.Hoʻonui anei ka hele ʻana o HP i ka ikaika o ka haunaele, ka hui ʻana o nā kahe wai hana a me ka hoʻololi ʻana i ka wela i hoʻohālikelike ʻia me nā paipu kumu (me ka ʻole o ka hoʻokomo ʻana i kahi lipine wili-wili)21.
ʻO ka helu Nusselt maʻamau (helix angle 45° a me 90°) me ka helu Reynolds no nā nanofluids like ʻole i hoʻohālikelike ʻia me nā paipu maʻamau.
Hōʻike nā kiʻi 13 a me 14 i ka helu awelika o ka friction (\(\frac{{f}_{Twisted}}{{f}_{Plain}}\)) a me ka poho puʻe (\(\frac{{\Delta P}) _ {Twisted}}{{\Delta P}_{Plain}}\}} ma kahi o 45° a me 90° no nā paipu ma'amau e ho'ohana ana i ka DW nanofluids, (GNPs-SDBS@DW) a me (GNPs-COOH@DW) ion exchanger. ( 0.025 wt %, 0.05 wt % a me 0.1 wt %). { {{f}_{Plain} }\)) a me ka poho puʻe (\(\frac{{ \Delta P}_{Twisted}}{{\Delta P }_{Plain}}\}) emi, ʻoi aku ke kiʻekiʻe o ka pākuʻi a me ka poho puʻe ma nā helu Reynolds haʻahaʻa. ʻEkolu manawa kiʻekiʻe ma mua o nā paipu maʻamau. Eia kekahi, i ka wā e kahe ai ka wai hana i kahi wikiwiki kiʻekiʻe, e emi ana ka coefficient o ka friction. Piʻi ka pilikia ma muli o ka piʻi ʻana o ka helu Reynolds, ʻo ka mānoanoa o ka papa palena. e emi ana, e alakai ana i ka emi ana o ka hopena o ka viscosity dynamic ma ka wahi i hoopilikiaia, ka emi ana o ka velocity gradients a me ka shear stress, a no ia mea, he emi i ka coefficient o friction21.ʻO ka maikaʻi o ka pale ʻana ma muli o ka hiki ʻana o TT a me ka piʻi ʻana o ka swirl e hopena i nā poho puʻe kiʻekiʻe loa no nā paipu TT heterogeneous ma mua o nā paipu kumu.Eia kekahi, no ka paipu kumu a me ka paipu TT, hiki ke ʻike ʻia ka piʻi ʻana o ke kaomi me ka wikiwiki o ka wai hana43.
Coefficient of friction (45° a me 90° helix angle) me ka helu Reynolds no nā nanofluids like ʻole i hoʻohālikelike ʻia me nā paipu maʻamau.
ʻO ka poho kaomi (45° a me 90° helix angle) ma ke ʻano he helu Reynolds no nā nanofluids like ʻole e pili ana i kahi paipu maʻamau.
Ma ka hōʻuluʻulu manaʻo, hōʻike ka Helu 15 i nā pae hoʻohālikelike hana (PEC) no nā mea hoʻololi wela me nā kihi 45° a me 90° i hoʻohālikelike ʻia me nā paipu maʻemaʻe (\(\frac{{PEC}_{Twisted}}{{PEC}_{Plain}} \ ) ) ma (0.025 wt.%, 0.05 wt.% a me 0.1 wt.%) me ka hoʻohana ʻana i ka DV, (VNP-SDBS@DV) a me ka covalent (VNP-COOH@DV) nanofluids.ʻO ka waiwai (\(\frac{{PEC}_{Twisted}}{{PEC}_{Plain}}\)) > 1 ma nā hihia ʻelua (45° a me 90° helix angle) ma ka mea hoʻololi wela.Eia hou, (\(\frac{{PEC}_{Twisted}}{{PEC}_{Plain}}\)) hiki i kona waiwai maikai ma Re = 11,000.Hōʻike ka mea hoʻololi wela 90° i ka piʻi iki o (\ (\frac{{PEC}_{Twisted}}{{PEC}_{Plain}}\)) i hoʻohālikelike ʻia me kahi mea hoʻololi wela 45°., Ma Re = 11,000 0.1 wt%-GNPs@SDBS ke kiʻekiʻe (\(\frac{{PEC}_{Twisted}}{{PEC}_{Plain}}\)), no ka laʻana, 1.25 no ke kihi hoʻololi wela 45° a me 1.27 no 90° kihi wela hoololi.ʻOi aku ia ma mua o hoʻokahi pākēneka o ka hakina nui, e hōʻike ana he ʻoi aku ka maikaʻi o nā paipu me nā hoʻokomo lipine wili ma mua o nā paipu maʻamau.ʻO ka mea nui, ʻo ka maikaʻi o ka hoʻololi ʻana i ka wela i hāʻawi ʻia e nā mea hoʻokomo lipine i hopena i ka piʻi nui ʻana o nā poho friction22.
Nā pae hoʻohālikelike kūpono no ka helu Reynolds o nā nanofluids like ʻole e pili ana i nā paipu maʻamau (45 ° a me 90 ° helix angle).
Hōʻike ʻo Appendix A i nā streamlines no nā mea hoʻololi wela 45 ° a me 90 ° ma Re = 7000 me ka hoʻohana ʻana i DW, 0.1 wt% -GNP-SDBS@DW a me 0.1 wt% -GNP-COOH@DW.ʻO nā streamlines i ka mokulele transverse ka hiʻohiʻona nui loa o ka hopena o nā hoʻokomo lipine wili i ke kahe nui.ʻO ka hoʻohana ʻana i nā mea hoʻololi wela 45 ° a me 90 ° e hōʻike ana i ka like o ka wikiwiki ma ka ʻāina kokoke i ka pā.I kēia manawa, hōʻike ʻo Appendix B i nā hiʻohiʻona velocity no nā mea hoʻololi wela 45 ° a me 90 ° ma Re = 7000 me ka hoʻohana ʻana i DW, 0.1 wt% -GNP-SDBS@DW a me 0.1 wt% -GNP-COOH@DW.Aia nā puka lou velocity i ʻekolu mau wahi like ʻole (nā ʻāpana), no ka laʻana, Plain-1 (P1 = −30mm), Plain-4 (P4 = 60mm) a me Plain-7 (P7 = 150mm).ʻO ka wikiwiki o ke kahe kokoke i ka pā paipu ka haʻahaʻa a piʻi ka wikiwiki o ka wai i ke kikowaena o ka paipu.Eia kekahi, i ka wā e hele ai i ka lewa ea, piʻi ka wahi o nā haʻahaʻa haʻahaʻa kokoke i ka pā.ʻO kēia ma muli o ka ulu ʻana o ka papa palena hydrodynamic, kahi e hoʻonui ai i ka mānoanoa o ka wahi haʻahaʻa haʻahaʻa kokoke i ka pā.Eia kekahi, ʻo ka hoʻonui ʻana i ka helu Reynolds e hoʻonui i ka pae holoʻokoʻa holoʻokoʻa ma nā ʻāpana keʻa a pau, ma laila e hōʻemi ai i ka mānoanoa o ka ʻāpana velocity haʻahaʻa ma ke kahawai39.
Ua loiloi ʻia nā nanosheets graphene covalently a me ka non-covalently i loko o nā hoʻokomo lipine wili me nā kihi helix o 45° a me 90°.Hoʻoholo ʻia ka mea hoʻololi wela me ka hoʻohana ʻana i ka SST k-omega turbulence model ma 7000 ≤ Re ≤ 17000. Ua helu ʻia nā waiwai thermophysical ma Tin = 308 K. I ka manawa like e wela ai ka paia o ka paipu wili i ka mahana mau o 330 K. COOH@DV) ua hoʻoheheʻe ʻia i ʻekolu mau ʻano nui, no ka laʻana (0.025 wt.%, 0.05 wt.% a me 0.1 wt.%).Ua noʻonoʻo ka haʻawina o kēia manawa i ʻeono mau kumu nui: ka wela o ka puka ʻana, ka helu hoʻoili wela, ka helu Nusselt awelika, ka helu o ka friction, ka poho puʻe, a me nā pae loiloi hana.Eia nā ʻike nui:
ʻO ka awelika o ka wela o ka puka ʻana (\({{T}_{out}}_{Nanofluids}\)/\({{T}_{out}}_{Basefluid}\)) he emi ma lalo o 1, ʻo ia hoʻi. pāhaʻi ʻole ʻO ka mahana puka o ka valence (ZNP-SDBS@DV) a me ka covalent (ZNP-COOH@DV) nanofluids he haʻahaʻa ma mua o ka wai kumu.I kēia manawa, ʻo ka awelika wela o ka puka ʻana (\({{T}_{out}}_{Twisted}\)/\({{T}_{out}}_{Plain}\)) waiwai > 1, e hōʻike ana i ka ʻoiaʻiʻo (45 ° a me 90 ° helix angle) ʻoi aku ka kiʻekiʻe o ka mahana o waho ma mua o nā paipu maʻamau.
Ma nā hihia ʻelua, hōʻike mau ʻia nā waiwai awelika o nā waiwai hoʻoili wela (nanofluid/base fluid) a me (twisted tube/tube maʻamau) >1.Non-covalent (GNPs-SDBS@DW) nanofluids i hōʻike i ka awelika piʻi kiʻekiʻe o ka hoʻoili wela, e pili ana i ka covalent (GNPs-COOH@DW) nanofluids.
ʻO ka pākuʻi maʻamau (\({f}_{Nanofluids}/{f}_{Basefluid}\)) o ka non-covalent (VNP-SDBS@DW) a me ka covalent (VNP-COOH@DW) nanofluids mau ≈1 .ʻO ka hoʻoheheʻe ʻana o nā nanofluid non-covalent (ZNP-SDBS@DV) a me ka covalent (ZNP-COOH@DV) (\({f}_{Twisted}/{f}_{Plain}\)) no nā manawa a pau > 3.
Ma nā hihia ʻelua (45° a me 90° helix angle), hōʻike nā nanofluids (GNPs-SDBS@DW) i ke kiʻekiʻe (\({\Delta P}_{Nanofluids}/{\Delta P}_{Basefluid}\)) 0.025 wt .% no 2.04%, 0.05 wt.% no 2.46% a me 0.1 wt.% no 3.44%.I kēia manawa, (GNPs-COOH@DW) nā nanofluids i hōʻike haʻahaʻa (\({\Delta P}_{Nanofluids}/{\Delta P}_{Basefluid}\)) mai 1.31% no 0.025 wt.% a i 1.65% he 0.05 % ma ke kaumaha.Eia hou, ka awelika poho puʻe (\({\Delta P}_{Twisted}/{\Delta P}_{Plain}\) o non-covalent (GNPs-SDBS@DW) a me covalent (GNPs-COOH@DW ))) nanofluids mau >3.
Ma nā hihia ʻelua (45° a me 90° nā kihi helix), ua hōʻike nā nanofluids (GNPs-SDBS@DW) i kahi kiʻekiʻe (\({PEC}_{Nanofluids}/{PEC} _{Basefluid}\)) @DW waiwai) , e laʻa me 0.025 wt.% - 1.17, 0.05 wt.% - 1.19, 0.1 wt.% - 1.26.I kēia hihia, ʻo nā waiwai o (\({PEC}_{Nanofluids}/{PEC}_{Basefluid}\)) e hoʻohana ana i (GNPs-COOH@DW) nanofluids he 1.02 no 0.025 wt.%, 1.05 no 0. , 05 wt.% a me 1.02 he 0.1% ma ke kaumaha.Eia hou, ma Re = 11,000, 0.1 wt%-GNPs@SDBS i hōʻike i nā waiwai kiʻekiʻe (\({PEC}_{Twisted}/{PEC}_{Plain}\)), e like me 1.25 no 45° helix angle a me ka huina helix 90° 1.27.
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Ka manawa hoʻouna: Mar-17-2023