Plume (fluid dynamics)


obere ụdị nke	fluid dynamics

Na hydrodynamics, plume ma ọ bụ kọlụm bụ ihe kwụ ọtọ nke otu mmiri na-agafe nke ọzọ. Ọtụtụ mmetụta na-achịkwa mmegharị nke mmiri ahụ, gụnyere momentum (inertia), diffusion na buoyancy (ọdịiche dị n'etiti). Mmiri dị ọcha na ábụ́bà dị ọcha na-akọwa ọfụma nke na-akpali kpamkpam site na mmetụta na-ese n'elu mmiri, n'otu n'otu. A na-akọwakarị ọfụma n'etiti ókè abụọ a dị ka ábụ́bà a manyere ma ọ bụ ụgbọ elu na-efe efe. "A na-akọwa ọdịdị dị ka ihe dị mma" mgbe, na enweghị ike ndị ọzọ ma ọ bụ mmegharị mbụ, mmiri na-abanye ga-arị elu. Ọnọdụ ebe njupụta nke mmiri mmiri pọmpụ dị ukwuu karịa gburugburu ya (ya bụ, n'ọnọdụ ka dị, ọdịdị ebumpụta ụwa ya ga-abụ imikpu), mana mgbawa ahụ nwere oke mbido zuru oke iji buru ya n'ebe dị anya n'ụzọ kwụ ọtọ, a kọwara dị ka ihe na-adịghị mma.^[1]

Ngagharị

Ọtụtụ mgbe, ka piom na-esi na isi iyi ya pụọ, ọ na-agbasawanye n'ihi ntinye nke mmiri gbara ya gburugburu n'akụkụ ya. Enwere ike imetụta ọdịdị nke plume site na nrịba na mmiri gburugburu (dịka ọmụmaatụ, ọ bụrụ na ifufe mpaghara na-efe n'otu ụzọ ahụ dị ka plume na-ebute ụgbọ elu na-asọ asọ). Nke a na-emekarị ka a na-ahụkarị ihe na-eme ka 'buoy-dominated' na mbụ ghọọ 'momentum-domined' (a na-ekwukarị na mgbanwe a bụ ọnụ ọgụgụ na-enweghị akụkụ a na-akpọ ọnụ ọgụgụ Richardson).

Ọfụma na nchọpụta

Ihe ọzọ dị mkpa bụ ma ọ bụrụ na plume nwere laminar flow ma ọ bụ turbulent flow. Dị ka ọ na-adịkarị, enwere mgbanwe site na laminar gaa na turbulent ka plume na-apụ na isi iyi ya. Enwere ike ịhụ ihe omume a n'ụzọ doro anya na anwụrụ ọkụ na-arị elu site na siga. Mgbe achọrọ izi ezi dị elu, enwere ike iji usoro mmiri na-agbanwe agbanwe (CFD) mee ihe iji mepụta ábụ́bà, mana nsonaazụ ya nwere ike ịdị n'uche ụdị turbulence ahọrọ. A na-emekarị CFD maka mpempe akwụkwọ rọket, ebe ihe ndị dị n'oge nwere ike ịdị na mgbakwunye na ihe ndị dị na gas. Ụdị ịme anwansị ndị a nwere ike ịdị mgbagwoju anya, gụnyere ọkụ ọkụ na radieshon na-ekpo ọkụ, yana (dịka ọmụmaatụ) a na-achọpụtakarị mwepu ogbunigwe ballistic site n'ịhụpụta mkpọ rọketi na-ekpo ọkụ.

Ndị na-emepụta ụgbọ mbara igwe na-echegbu onwe ha mgbe ụfọdụ maka mmetọ nke usoro njikwa àgwà na-ebugharị na subsystems dị nro dị ka usoro anyanwụ na ndị na-eso kpakpando, ma ọ bụ na mmetọ ya nke injin rocket na-ebute n'elu ọnwa ma ọ bụ mbara ala ebe ha nwere ike ịkpata mmebi mpaghara ma ọ bụ ọbụna ọgba aghara n'etiti oge na ikuku mbara ala.

Ihe ọzọ a na-ahụ anya nke ọma na anwụrụ ọkụ si na siga na-asọpụta bụ na isi ihe na-asọpụta, ma ọ bụ mmalite-plum, na-adịkarị n'ụdị mgbanaka-vortex (mgbanaka anwụrụ ọkụ).^[2]

Ụdị n'ụdị

Mmetọ ndị a tọhapụrụ n'ala nwere ike ịrụ ọrụ n'ime mmiri dị n'okpuru ala, na-eduga na mmetọ mmiri dị n"okpuru ala. A na-akpọ mmiri na-emetọ emetọ n'ime mmiri dị n'ime ala a na-akpọ plume, na ọnụ ya na-agagharị agagharị a na-eme ka ọ bụrụ plume fronts.A na-eji plumes chọta, map, na tụọ mmetọ mmiri n'ime mkpokọta mmiri nke aquifer, yana ihu ihu iji chọpụta ntụziaka na ọsọ nke mmetọ na-agbasa na ya.^[3]

Plumes dị oke mkpa na modeling nke ikuku nke mmetọ ikuku. Otu ọrụ a ma ama na isiokwu nke ikuku mmetọ bụ nke Gary Briggs.^[4]^[5]

Ọkụ bụ nke gas na-ebili n'elu isi iyi okpomọkụ na-emepụta. Gas ahụ na-arị elu n'ihi na mgbasa nke okpomọkụ na-eme ka gas na-ekpo ọkụ ghara ịdị arọ karịa gas na-ajụ oyi gbara ya gburugburu.

Nkọwa dị mfe ga-eme ka ọtụtụ njirimara nke mepụtara nke ọma, nke na-agbagwoju anya nyochaa.Ọtụtụ n'ime arụmụka scaling kpochapụwo ka ewepụtara na nchịkọta nyocha na nyocha ụlọ nyocha nke akọwara n'ime akwụkwọ nwere mmetụta nke Bruce Morton, GI. Taylor na Stewart Turner^[6]kọwara na akwụkwọ nwere mmetụta na akwụkwọ a na-akọwa ọrụ a na ọrụ na-esote na akwụkwọ edemede a ma ama nke Stewart Turner^[7].^[8]

Ọ na-abụkarị nke zuru oke iche na gradient na-edozi gradient nrụgide site na gradient dị anya site na plume (nke a dị ka mkpokọta Boussinesq nke mbụ).
A na-emepụta nkesa nke njupụta na ọsọ gafee pensụl ma ọ bụ na nkesa Gaussian dị mfe ma ọ bụ ma ọ bụghị ya ka a na-ewere ya dị ka otu gafee pensịl (nke a na-akpọ 'elu okpu').
Ọnụ ọgụgụ nke ịdọrọ n'ime plume ahụ kwekọrọ na ọsọ ọsọ mpaghara.^[7] Ọ bụ ezie na na mbụ e chere na ọ bụ ihe na-adịgide adịgide, ọrụ na-adịbeghị anya egosila na coefficient na-adọkpụ dịgasị iche na nọmba Richardson mpaghara.^[9] Ọnụ ọgụgụ ndị a na-ahụkarị maka coefficient na-adọkpụ bụ ihe dị ka 0.08 maka ụgbọ elu kwụ ọtọ na 0.12 maka ábụ́bà kwụ ọtọ, ábụ́tụ̀tụ̀ na-adọrọ adọrọ ebe maka ábúningi na-agbadata, coefficient adọkpụ bụ banyere 0.6.
Usoro nchekwa maka oke (gụnyere ịdọrọ), na ike na ọfụma zuru ezu maka nkọwa zuru ezu nke ọfụm ahụ n'ọtụtụ ọnọdụ.^[7]^[10] Maka oghere na-arị elu dị mfe, usoro ndị a na-ebu amụma na oghere ahụ ga-agbasawanye na ọkara oghere nke ihe dị ka 6 ruo 15 degrees.

Ihe osise Gaussian

^[11]Enwere ike iji ụdị Gaussian plume mee ihe n'ọtụtụ ọnọdụ mgbanwe mgbanwe mmiri iji gbakọọ nkesa nke solutes, dị ka ntọhapụ mkpokọ anwụrụ ọkụ ma ọ bụ mmetọ ewepụtara n'osimiri. Fickian na-ekesa nkesa Gaussian, wee soro nkesa Gaussian (ụdị mgbịrịgba). Maka ịgbakọ ọnụ ọgụgụ a tụrụ anya ya nke otu isi iyi na-enweghị isi, anyị na-atụle oke a tọhapụrụ n'otu oge, na otu mpaghara. $M$ $x$ Nke a ga-enye usoro ndị a:^[12]

$C(x,t)={\frac {M}{\sqrt {4\pi Dt}}}\exp \left({\frac {(x-x_{0})^{2}}{4D(t-t_{0})}}\right)$

ebe bụ oke a tọhapụrụ n'oge na ebe, ọ bụkwa diffusivity. $M$ $t=t_{0}$ $x=x_{0}$ $D$ $\left[{\frac {{\text{m}}^{2}}{\text{s}}}\right]$ Njikọ a na-eme atụmatụ anọ na-esonụ:^[13]

A na-ahapụ ụyọkọ ahụ ozugbo. $M$
A na-ahapụ oke ahụ na ngalaba na-enweghị njedebe. $M$
Uka na-agbasa naanị site na mgbasa..
Mgbasa anaghị adị iche na oghere.^[11]

Ihe ngosi

Hụkwa Ihe ọzọ

Edensibia

↑ Turner, J.S. (1979), "Buoyancy effects in fluids", Ch.6, pp.165--&, Cambridge University Press
↑ Turner, J. S. (1962). The Starting Plume in Neutral Surroundings, J. Fluid Mech. vol 13, pp356-368
↑ Fetter, C.W. Jr 1998 Contaminant Hydrogeology
↑ Briggs, Gary A. (1975). Plume Rise Predictions, Chapter 3 in Lectures on Air Pollution and Environmental Impact Analysis, Duanne A. Haugen, editor, Amer. Met. Soc.
↑ Beychok, Milton R. (2005). Fundamentals Of Stack Gas Dispersion, 4th, author-published. ISBN 0-9644588-0-2.
↑ Scase, M. M., Caulfield, C. P., Dalziel, S. B. & Hunt, J. C. R. (2006). Time-dependent plumes and jets with decreasing source strengths, J. Fluid Mech. vol 563, pp443-461
↑ ^7.0 ^7.1 ^7.2 Morton, B. R., Turner, J. S., and Taylor, G.I. (1956), Turbulent gravitational convection from maintained and instantaneous sources, P. Roy. Soc. Lond., vol. 234, pp.1--&
↑ Turner (1979-12-20). Buoyancy Effects in Fluids (in en). Cambridge University Press. ISBN 978-0-521-29726-4.
↑ Kaminski, E. Tait, S. and Carazzo, G. (2005), Turbulent entrainment in jets with arbitrary buoyancy, J. Fluid Mech., vol. 526, pp.361--376
↑ Woods, A.W. (2010), Turbulent plumes in nature, Annu. Rev. Fluid Mech., Vol. 42, pp. 391--412
↑ ^11.0 ^11.1 Connolly. Gaussian Plume Model. personalpages.manchester.ac.uk. Retrieved on 25 April 2017. Kpọpụta njehie: Invalid <ref> tag; name "connolly model" defined multiple times with different content
↑ Heidi Nepf. 1.061 Transport Processes in the Environment. Fall 2008. Massachusetts Institute of Technology: MIT OpenCourseWare, https://ocw.mit.edu License: Creative Commons BY-NC-SA.
↑ Variano. Mass Transport in Environmental Flows. UC Berkeley.

[1] Turner, J.S. (1979), "Buoyancy effects in fluids", Ch.6, pp.165--&, Cambridge University Press

[2] Turner, J. S. (1962). The Starting Plume in Neutral Surroundings, J. Fluid Mech. vol 13, pp356-368

[3] Fetter, C.W. Jr 1998 Contaminant Hydrogeology

[4] Briggs, Gary A. (1975). Plume Rise Predictions, Chapter 3 in Lectures on Air Pollution and Environmental Impact Analysis, Duanne A. Haugen, editor, Amer. Met. Soc.

[5] Beychok, Milton R. (2005). Fundamentals Of Stack Gas Dispersion, 4th, author-published. ISBN 0-9644588-0-2.

[6] Scase, M. M., Caulfield, C. P., Dalziel, S. B. & Hunt, J. C. R. (2006). Time-dependent plumes and jets with decreasing source strengths, J. Fluid Mech. vol 563, pp443-461

[morton_turb-7] 7.0 ^7.1 ^7.2 Morton, B. R., Turner, J. S., and Taylor, G.I. (1956), Turbulent gravitational convection from maintained and instantaneous sources, P. Roy. Soc. Lond., vol. 234, pp.1--&

[8] Turner (1979-12-20). Buoyancy Effects in Fluids (in en). Cambridge University Press. ISBN 978-0-521-29726-4.

[9] Kaminski, E. Tait, S. and Carazzo, G. (2005), Turbulent entrainment in jets with arbitrary buoyancy, J. Fluid Mech., vol. 526, pp.361--376

[10] Woods, A.W. (2010), Turbulent plumes in nature, Annu. Rev. Fluid Mech., Vol. 42, pp. 391--412

[connolly_model-11] 11.0 ^11.1 Connolly. Gaussian Plume Model. personalpages.manchester.ac.uk. Retrieved on 25 April 2017. Kpọpụta njehie: Invalid <ref> tag; name "connolly model" defined multiple times with different content

[12] Heidi Nepf. 1.061 Transport Processes in the Environment. Fall 2008. Massachusetts Institute of Technology: MIT OpenCourseWare, https://ocw.mit.edu License: Creative Commons BY-NC-SA.

[13] Variano. Mass Transport in Environmental Flows. UC Berkeley.

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