Analysis of the vortex core and turbulence structure behind axial fans in a straight pipe using PIV, LDA and HWA methods
The dissertation investigates the structure of turbulent swirl flow generated by the axial fan impellers. The complexity of three-dimensional, non-homogeneous, anisotropic turbulent velocity fields required complex experimental and theoretical approach, associated with the complex numerical procedur...
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| creator | Čantrak Đorđe |
| description | The dissertation investigates the structure of turbulent swirl flow generated
by the axial fan impellers. The complexity of three-dimensional,
non-homogeneous, anisotropic turbulent velocity fields required complex
experimental and theoretical approach, associated with the complex numerical
procedures. Mathematical interpretation of the structural analysis of
turbulence is presented using the correlation-spectral theory of turbulence.
This theoretical consideration provides adequate physical interpretation of
complex interactions between the average and fluctuating velocity fields that
characterize the processes of turbulent transfer. Analysis of the vortex core
and the statistical characteristics of turbulent swirl flow in straight pipe
behind axial fans is based on the latest experimental researches. In this
sense, modern measurement systems that include classical probes, stereo
particle image velocimetry (SPIV), high speed SPIV (TR PIV), laser Doppler
anemometry (LDA) – one- and two-component and original hot-wire anemometers
(HWA) were all applied. Measurements and measurement principles are discussed
along with sophisticated numerical-measurement methods for data acquisition
and statistical processing of measured data and together with calibration and
error analysis and measurement uncertainty. Numerous experiments were carried
out in the modified existing test rig and in the entire newly built
experimental test rig. Based on the original measurement results, the PhD
thesis examines in detail the influence of the type and operating regime of
axial fan on turbulence structure and turbulent transfer mechanism. In
particular, the phenomenon of the vortex core precession as well as the
phenomenon of non-local turbulent transfer and non-gradient turbulent
diffusion is studied. In addition, the effects of Reynolds and swirl number,
and the effects of rotation speed and blade angle on these phenomena are
investigated. The physical interpretation of experimental data indicates
significant structural properties of a turbulent vortex core and a shear
layer. Experimental and correlation analysis examines the evolution of
statistical characteristics and correlation moments, which is the basis for
drawing conclusions about the extreme turbulence non-homogeneity and
anisotropy. The measured distributions of turbulent stresses enabled the
formation of anisotropy invariant maps for various fan blade angles, so the
important conclusions about the influence of fan duty |
| format | Dissertation |
| fullrecord | <record><control><sourceid>europeana_1GC</sourceid><recordid>TN_cdi_europeana_collections_9200447_BibliographicResource_3000095543323</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>9200447_BibliographicResource_3000095543323</sourcerecordid><originalsourceid>FETCH-europeana_collections_9200447_BibliographicResource_30000955433233</originalsourceid><addsrcrecordid>eNqtjEFqwzAQRb3JIqS9wxygARM5hCzdJMWBLkoJ7dKMlbE1oGiMRiru7euWHiF_8_m8z1sWUx3QfysrSA_JEXxJTDSBlUiA4Qopxy57CpZAU8x23gQdOZ4ZToweegwKHAB_D8iDSzDySJCVwwBv548neD3Wf7Lms4YbJSdXfSgWPXqlx_9eFc3L6XJo1pSjjIQBWyvek00sQdv9piyratc-c-dZhoijY_tOKjlaak05Z7_dVsZsjLmj6gcyE2Cl</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>dissertation</recordtype></control><display><type>dissertation</type><title>Analysis of the vortex core and turbulence structure behind axial fans in a straight pipe using PIV, LDA and HWA methods</title><source>Europeana Collections</source><creator>Čantrak Đorđe</creator><creatorcontrib>Čantrak Đorđe ; Lečić Milan ; Nedeljković Miloš ; Vukoslavčević Petar ; Ristić Slavica ; Benišek Miroslav</creatorcontrib><description>The dissertation investigates the structure of turbulent swirl flow generated
by the axial fan impellers. The complexity of three-dimensional,
non-homogeneous, anisotropic turbulent velocity fields required complex
experimental and theoretical approach, associated with the complex numerical
procedures. Mathematical interpretation of the structural analysis of
turbulence is presented using the correlation-spectral theory of turbulence.
This theoretical consideration provides adequate physical interpretation of
complex interactions between the average and fluctuating velocity fields that
characterize the processes of turbulent transfer. Analysis of the vortex core
and the statistical characteristics of turbulent swirl flow in straight pipe
behind axial fans is based on the latest experimental researches. In this
sense, modern measurement systems that include classical probes, stereo
particle image velocimetry (SPIV), high speed SPIV (TR PIV), laser Doppler
anemometry (LDA) – one- and two-component and original hot-wire anemometers
(HWA) were all applied. Measurements and measurement principles are discussed
along with sophisticated numerical-measurement methods for data acquisition
and statistical processing of measured data and together with calibration and
error analysis and measurement uncertainty. Numerous experiments were carried
out in the modified existing test rig and in the entire newly built
experimental test rig. Based on the original measurement results, the PhD
thesis examines in detail the influence of the type and operating regime of
axial fan on turbulence structure and turbulent transfer mechanism. In
particular, the phenomenon of the vortex core precession as well as the
phenomenon of non-local turbulent transfer and non-gradient turbulent
diffusion is studied. In addition, the effects of Reynolds and swirl number,
and the effects of rotation speed and blade angle on these phenomena are
investigated. The physical interpretation of experimental data indicates
significant structural properties of a turbulent vortex core and a shear
layer. Experimental and correlation analysis examines the evolution of
statistical characteristics and correlation moments, which is the basis for
drawing conclusions about the extreme turbulence non-homogeneity and
anisotropy. The measured distributions of turbulent stresses enabled the
formation of anisotropy invariant maps for various fan blade angles, so the
important conclusions about the influence of fan duty point on anisotropy and
turbulence structure in the core, shear layer and sound flow region were
obtained. Additional pieces of information on turbulent structure physics
were obtained on the basis of experimentally determined autocorrelation
functions and turbulence integral scales, and also by the analysis of
spectral functions of circumferential velocity fluctuations. Impacts of the
fan types on the statistical moments of the third and fourth order, and on
the generation of the vorticity field and vortex core precession movement,
are determined. Joint experimental and theoretical-numerical analysis allowed
for meaningful and important conclusions about various effects of various
axial fan impellers on the turbulent vortex core and turbulence structure.
U disertaciji se istražuje struktura turbulentnog vihornog strujanja koje je
generisano obrtnim kolom aksijalnog ventilatora. Kompleksnost trodimenzijskog
nehomogenog anizotropnog turbulentnog brzinskog polja zahtevala je složen
eksperimentalni i teorijski pristup, sjedinjen sa kompleksnim numeričkim
postupcima. Primenom korelaciono-spektralne teorije turbulencije izložena je
matematička interpretacija strukturalne analize turbulencije. Ovakvim
teorijskim razmatranjem data su fizička tumačenja složenih međudejstava
srednjeg i fluktuacionog brzinskog polja koja karakterišu procese
turbulentnog prenosa. Analiza vrtložnog jezgra i statističkih karakteristika
turbulentnog vihornog strujanja u cevi iza kola aksijalnih ventilatora
zasniva se na najsavremenijim eksperimentalnim istraživanjima. U tom smislu
primenjeni su savremeni merni sistemi koji obuhvataju klasične merne sonde,
stereo PIV anemometriju, stereo PIV sa brzim kamerama i laserima (TR PIV),
laser Dopler anemometriju (LDA) i to jednokomponentnu i dvokomponentnu, kao i
originalne anemometarske sonde sa zagrejanim vlaknima (HWA). Merenja i
principi merenja su zajedno razmatrani sa sofisticiranim merno-numeričkim
metodama za akviziciju i statističku obradu merenih podataka, kao i za
kalibraciju i analizu grešaka i merne nesigurnosti. Brojni eksperimenti su
realizovani kako na instalaciji koja je dobijena modifikacijama postojećeg
mernog štanda, tako i na celokupno novoj izgrađenoj eksperimentalnoj
instalaciji.Na osnovu originalnih rezultata merenja u radu se detaljno
istražuje uticaj tipa i režima rada aksijalnog ventilatora na strukturu
turbulencije i mehanizam turbulentnog prenosa. Posebno se proučava fenomen
precesije vrtložnog jezgra, kao i fenomeni nelokalnog turbulentnog prenosa i
negradijentne turbulentne difuzije. Pri tome se analiziraju uticaji
Rejnoldsovog i vihornog broja, kao i broja obrtaja i uglova lopatica kola na
ove pojave. Fizička interpretacija eksperimentalnih podataka ukazuje na
značajna strukturalna svojstva vrtložnog turbulentnog jezgra i smicajnog
sloja. Eksperimentalno-korelacionom analizom istražuje se evolucija
statističkih karakteristika i korelacionih momenata, na osnovu čega se
zaključuje o izrazitoj nehomogenosti i anizotropnosti turbulencije. Izmerene
raspodele turbulentnih napona omogućile su formiranje invarijantnih mapa
anizotropnosti za različite uglove lopatica kola, tako da su dobijeni
značajni zaključci o uticaju režima rada ventilatora na anizotropnost i
strukturu turbulencije u jezgru, smicajnom sloju i osnovnom strujanju.
Dodatne fizičke informacije o strukturi turbulencije dobijene su iz
eksperimentalno određenih autokorelacionih funkcija i integralnih razmera
turbulencije, kao i pomoću analize spektralne funkcije obimskih fluktuacionih
brzina. Utvrđeni su uticaji vrste ventilatora na raspodelu statističkih
momenata trećeg i četvrtog reda, kao i na generisanje polja vrtložnosti i
precesiono kretanje vrtložnog jezgra. Združenom eksperimentalnom i
teorijsko-numeričkom analizom dobijeni su značajni zaključci o različitim
uticajima obrtnih kola aksijalnih ventilatora na turbulentno vrtložno jezgro
i strukturu turbulencije.</description><language>srp</language><publisher>University of Belgrade, Faculty of Mechanical Engineering</publisher><subject>aksijalni ventilator ; anisotropy ; anizotropnost ; axial fan ; invariants ; invarijante ; LDA ; PIV ; swirl ; turbulence ; turbulencija ; vihor ; vortex core ; vrtložno jezgro</subject><creationdate>2012</creationdate><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktohtml>$$Uhttps://data.europeana.eu/item/9200447/BibliographicResource_3000095543323$$EHTML$$P50$$Geuropeana$$Hfree_for_read</linktohtml><link.rule.ids>311,780,38515,75946</link.rule.ids><linktorsrc>$$Uhttps://data.europeana.eu/item/9200447/BibliographicResource_3000095543323$$EView_record_in_Europeana$$FView_record_in_$$GEuropeana$$Hfree_for_read</linktorsrc></links><search><creatorcontrib>Čantrak Đorđe</creatorcontrib><title>Analysis of the vortex core and turbulence structure behind axial fans in a straight pipe using PIV, LDA and HWA methods</title><description>The dissertation investigates the structure of turbulent swirl flow generated
by the axial fan impellers. The complexity of three-dimensional,
non-homogeneous, anisotropic turbulent velocity fields required complex
experimental and theoretical approach, associated with the complex numerical
procedures. Mathematical interpretation of the structural analysis of
turbulence is presented using the correlation-spectral theory of turbulence.
This theoretical consideration provides adequate physical interpretation of
complex interactions between the average and fluctuating velocity fields that
characterize the processes of turbulent transfer. Analysis of the vortex core
and the statistical characteristics of turbulent swirl flow in straight pipe
behind axial fans is based on the latest experimental researches. In this
sense, modern measurement systems that include classical probes, stereo
particle image velocimetry (SPIV), high speed SPIV (TR PIV), laser Doppler
anemometry (LDA) – one- and two-component and original hot-wire anemometers
(HWA) were all applied. Measurements and measurement principles are discussed
along with sophisticated numerical-measurement methods for data acquisition
and statistical processing of measured data and together with calibration and
error analysis and measurement uncertainty. Numerous experiments were carried
out in the modified existing test rig and in the entire newly built
experimental test rig. Based on the original measurement results, the PhD
thesis examines in detail the influence of the type and operating regime of
axial fan on turbulence structure and turbulent transfer mechanism. In
particular, the phenomenon of the vortex core precession as well as the
phenomenon of non-local turbulent transfer and non-gradient turbulent
diffusion is studied. In addition, the effects of Reynolds and swirl number,
and the effects of rotation speed and blade angle on these phenomena are
investigated. The physical interpretation of experimental data indicates
significant structural properties of a turbulent vortex core and a shear
layer. Experimental and correlation analysis examines the evolution of
statistical characteristics and correlation moments, which is the basis for
drawing conclusions about the extreme turbulence non-homogeneity and
anisotropy. The measured distributions of turbulent stresses enabled the
formation of anisotropy invariant maps for various fan blade angles, so the
important conclusions about the influence of fan duty point on anisotropy and
turbulence structure in the core, shear layer and sound flow region were
obtained. Additional pieces of information on turbulent structure physics
were obtained on the basis of experimentally determined autocorrelation
functions and turbulence integral scales, and also by the analysis of
spectral functions of circumferential velocity fluctuations. Impacts of the
fan types on the statistical moments of the third and fourth order, and on
the generation of the vorticity field and vortex core precession movement,
are determined. Joint experimental and theoretical-numerical analysis allowed
for meaningful and important conclusions about various effects of various
axial fan impellers on the turbulent vortex core and turbulence structure.
U disertaciji se istražuje struktura turbulentnog vihornog strujanja koje je
generisano obrtnim kolom aksijalnog ventilatora. Kompleksnost trodimenzijskog
nehomogenog anizotropnog turbulentnog brzinskog polja zahtevala je složen
eksperimentalni i teorijski pristup, sjedinjen sa kompleksnim numeričkim
postupcima. Primenom korelaciono-spektralne teorije turbulencije izložena je
matematička interpretacija strukturalne analize turbulencije. Ovakvim
teorijskim razmatranjem data su fizička tumačenja složenih međudejstava
srednjeg i fluktuacionog brzinskog polja koja karakterišu procese
turbulentnog prenosa. Analiza vrtložnog jezgra i statističkih karakteristika
turbulentnog vihornog strujanja u cevi iza kola aksijalnih ventilatora
zasniva se na najsavremenijim eksperimentalnim istraživanjima. U tom smislu
primenjeni su savremeni merni sistemi koji obuhvataju klasične merne sonde,
stereo PIV anemometriju, stereo PIV sa brzim kamerama i laserima (TR PIV),
laser Dopler anemometriju (LDA) i to jednokomponentnu i dvokomponentnu, kao i
originalne anemometarske sonde sa zagrejanim vlaknima (HWA). Merenja i
principi merenja su zajedno razmatrani sa sofisticiranim merno-numeričkim
metodama za akviziciju i statističku obradu merenih podataka, kao i za
kalibraciju i analizu grešaka i merne nesigurnosti. Brojni eksperimenti su
realizovani kako na instalaciji koja je dobijena modifikacijama postojećeg
mernog štanda, tako i na celokupno novoj izgrađenoj eksperimentalnoj
instalaciji.Na osnovu originalnih rezultata merenja u radu se detaljno
istražuje uticaj tipa i režima rada aksijalnog ventilatora na strukturu
turbulencije i mehanizam turbulentnog prenosa. Posebno se proučava fenomen
precesije vrtložnog jezgra, kao i fenomeni nelokalnog turbulentnog prenosa i
negradijentne turbulentne difuzije. Pri tome se analiziraju uticaji
Rejnoldsovog i vihornog broja, kao i broja obrtaja i uglova lopatica kola na
ove pojave. Fizička interpretacija eksperimentalnih podataka ukazuje na
značajna strukturalna svojstva vrtložnog turbulentnog jezgra i smicajnog
sloja. Eksperimentalno-korelacionom analizom istražuje se evolucija
statističkih karakteristika i korelacionih momenata, na osnovu čega se
zaključuje o izrazitoj nehomogenosti i anizotropnosti turbulencije. Izmerene
raspodele turbulentnih napona omogućile su formiranje invarijantnih mapa
anizotropnosti za različite uglove lopatica kola, tako da su dobijeni
značajni zaključci o uticaju režima rada ventilatora na anizotropnost i
strukturu turbulencije u jezgru, smicajnom sloju i osnovnom strujanju.
Dodatne fizičke informacije o strukturi turbulencije dobijene su iz
eksperimentalno određenih autokorelacionih funkcija i integralnih razmera
turbulencije, kao i pomoću analize spektralne funkcije obimskih fluktuacionih
brzina. Utvrđeni su uticaji vrste ventilatora na raspodelu statističkih
momenata trećeg i četvrtog reda, kao i na generisanje polja vrtložnosti i
precesiono kretanje vrtložnog jezgra. Združenom eksperimentalnom i
teorijsko-numeričkom analizom dobijeni su značajni zaključci o različitim
uticajima obrtnih kola aksijalnih ventilatora na turbulentno vrtložno jezgro
i strukturu turbulencije.</description><subject>aksijalni ventilator</subject><subject>anisotropy</subject><subject>anizotropnost</subject><subject>axial fan</subject><subject>invariants</subject><subject>invarijante</subject><subject>LDA</subject><subject>PIV</subject><subject>swirl</subject><subject>turbulence</subject><subject>turbulencija</subject><subject>vihor</subject><subject>vortex core</subject><subject>vrtložno jezgro</subject><fulltext>true</fulltext><rsrctype>dissertation</rsrctype><creationdate>2012</creationdate><recordtype>dissertation</recordtype><sourceid>1GC</sourceid><recordid>eNqtjEFqwzAQRb3JIqS9wxygARM5hCzdJMWBLkoJ7dKMlbE1oGiMRiru7euWHiF_8_m8z1sWUx3QfysrSA_JEXxJTDSBlUiA4Qopxy57CpZAU8x23gQdOZ4ZToweegwKHAB_D8iDSzDySJCVwwBv548neD3Wf7Lms4YbJSdXfSgWPXqlx_9eFc3L6XJo1pSjjIQBWyvek00sQdv9piyratc-c-dZhoijY_tOKjlaak05Z7_dVsZsjLmj6gcyE2Cl</recordid><startdate>20120730</startdate><enddate>20120730</enddate><creator>Čantrak Đorđe</creator><general>University of Belgrade, Faculty of Mechanical Engineering</general><scope>1GC</scope></search><sort><creationdate>20120730</creationdate><title>Analysis of the vortex core and turbulence structure behind axial fans in a straight pipe using PIV, LDA and HWA methods</title><author>Čantrak Đorđe</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-europeana_collections_9200447_BibliographicResource_30000955433233</frbrgroupid><rsrctype>dissertations</rsrctype><prefilter>dissertations</prefilter><language>srp</language><creationdate>2012</creationdate><topic>aksijalni ventilator</topic><topic>anisotropy</topic><topic>anizotropnost</topic><topic>axial fan</topic><topic>invariants</topic><topic>invarijante</topic><topic>LDA</topic><topic>PIV</topic><topic>swirl</topic><topic>turbulence</topic><topic>turbulencija</topic><topic>vihor</topic><topic>vortex core</topic><topic>vrtložno jezgro</topic><toplevel>online_resources</toplevel><creatorcontrib>Čantrak Đorđe</creatorcontrib><collection>Europeana Collections</collection></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext_linktorsrc</fulltext></delivery><addata><au>Čantrak Đorđe</au><format>dissertation</format><genre>dissertation</genre><ristype>THES</ristype><Advisor>Lečić Milan</Advisor><Advisor>Nedeljković Miloš</Advisor><Advisor>Vukoslavčević Petar</Advisor><Advisor>Ristić Slavica</Advisor><Advisor>Benišek Miroslav</Advisor><btitle>Analysis of the vortex core and turbulence structure behind axial fans in a straight pipe using PIV, LDA and HWA methods</btitle><date>2012-07-30</date><risdate>2012</risdate><abstract>The dissertation investigates the structure of turbulent swirl flow generated
by the axial fan impellers. The complexity of three-dimensional,
non-homogeneous, anisotropic turbulent velocity fields required complex
experimental and theoretical approach, associated with the complex numerical
procedures. Mathematical interpretation of the structural analysis of
turbulence is presented using the correlation-spectral theory of turbulence.
This theoretical consideration provides adequate physical interpretation of
complex interactions between the average and fluctuating velocity fields that
characterize the processes of turbulent transfer. Analysis of the vortex core
and the statistical characteristics of turbulent swirl flow in straight pipe
behind axial fans is based on the latest experimental researches. In this
sense, modern measurement systems that include classical probes, stereo
particle image velocimetry (SPIV), high speed SPIV (TR PIV), laser Doppler
anemometry (LDA) – one- and two-component and original hot-wire anemometers
(HWA) were all applied. Measurements and measurement principles are discussed
along with sophisticated numerical-measurement methods for data acquisition
and statistical processing of measured data and together with calibration and
error analysis and measurement uncertainty. Numerous experiments were carried
out in the modified existing test rig and in the entire newly built
experimental test rig. Based on the original measurement results, the PhD
thesis examines in detail the influence of the type and operating regime of
axial fan on turbulence structure and turbulent transfer mechanism. In
particular, the phenomenon of the vortex core precession as well as the
phenomenon of non-local turbulent transfer and non-gradient turbulent
diffusion is studied. In addition, the effects of Reynolds and swirl number,
and the effects of rotation speed and blade angle on these phenomena are
investigated. The physical interpretation of experimental data indicates
significant structural properties of a turbulent vortex core and a shear
layer. Experimental and correlation analysis examines the evolution of
statistical characteristics and correlation moments, which is the basis for
drawing conclusions about the extreme turbulence non-homogeneity and
anisotropy. The measured distributions of turbulent stresses enabled the
formation of anisotropy invariant maps for various fan blade angles, so the
important conclusions about the influence of fan duty point on anisotropy and
turbulence structure in the core, shear layer and sound flow region were
obtained. Additional pieces of information on turbulent structure physics
were obtained on the basis of experimentally determined autocorrelation
functions and turbulence integral scales, and also by the analysis of
spectral functions of circumferential velocity fluctuations. Impacts of the
fan types on the statistical moments of the third and fourth order, and on
the generation of the vorticity field and vortex core precession movement,
are determined. Joint experimental and theoretical-numerical analysis allowed
for meaningful and important conclusions about various effects of various
axial fan impellers on the turbulent vortex core and turbulence structure.
U disertaciji se istražuje struktura turbulentnog vihornog strujanja koje je
generisano obrtnim kolom aksijalnog ventilatora. Kompleksnost trodimenzijskog
nehomogenog anizotropnog turbulentnog brzinskog polja zahtevala je složen
eksperimentalni i teorijski pristup, sjedinjen sa kompleksnim numeričkim
postupcima. Primenom korelaciono-spektralne teorije turbulencije izložena je
matematička interpretacija strukturalne analize turbulencije. Ovakvim
teorijskim razmatranjem data su fizička tumačenja složenih međudejstava
srednjeg i fluktuacionog brzinskog polja koja karakterišu procese
turbulentnog prenosa. Analiza vrtložnog jezgra i statističkih karakteristika
turbulentnog vihornog strujanja u cevi iza kola aksijalnih ventilatora
zasniva se na najsavremenijim eksperimentalnim istraživanjima. U tom smislu
primenjeni su savremeni merni sistemi koji obuhvataju klasične merne sonde,
stereo PIV anemometriju, stereo PIV sa brzim kamerama i laserima (TR PIV),
laser Dopler anemometriju (LDA) i to jednokomponentnu i dvokomponentnu, kao i
originalne anemometarske sonde sa zagrejanim vlaknima (HWA). Merenja i
principi merenja su zajedno razmatrani sa sofisticiranim merno-numeričkim
metodama za akviziciju i statističku obradu merenih podataka, kao i za
kalibraciju i analizu grešaka i merne nesigurnosti. Brojni eksperimenti su
realizovani kako na instalaciji koja je dobijena modifikacijama postojećeg
mernog štanda, tako i na celokupno novoj izgrađenoj eksperimentalnoj
instalaciji.Na osnovu originalnih rezultata merenja u radu se detaljno
istražuje uticaj tipa i režima rada aksijalnog ventilatora na strukturu
turbulencije i mehanizam turbulentnog prenosa. Posebno se proučava fenomen
precesije vrtložnog jezgra, kao i fenomeni nelokalnog turbulentnog prenosa i
negradijentne turbulentne difuzije. Pri tome se analiziraju uticaji
Rejnoldsovog i vihornog broja, kao i broja obrtaja i uglova lopatica kola na
ove pojave. Fizička interpretacija eksperimentalnih podataka ukazuje na
značajna strukturalna svojstva vrtložnog turbulentnog jezgra i smicajnog
sloja. Eksperimentalno-korelacionom analizom istražuje se evolucija
statističkih karakteristika i korelacionih momenata, na osnovu čega se
zaključuje o izrazitoj nehomogenosti i anizotropnosti turbulencije. Izmerene
raspodele turbulentnih napona omogućile su formiranje invarijantnih mapa
anizotropnosti za različite uglove lopatica kola, tako da su dobijeni
značajni zaključci o uticaju režima rada ventilatora na anizotropnost i
strukturu turbulencije u jezgru, smicajnom sloju i osnovnom strujanju.
Dodatne fizičke informacije o strukturi turbulencije dobijene su iz
eksperimentalno određenih autokorelacionih funkcija i integralnih razmera
turbulencije, kao i pomoću analize spektralne funkcije obimskih fluktuacionih
brzina. Utvrđeni su uticaji vrste ventilatora na raspodelu statističkih
momenata trećeg i četvrtog reda, kao i na generisanje polja vrtložnosti i
precesiono kretanje vrtložnog jezgra. Združenom eksperimentalnom i
teorijsko-numeričkom analizom dobijeni su značajni zaključci o različitim
uticajima obrtnih kola aksijalnih ventilatora na turbulentno vrtložno jezgro
i strukturu turbulencije.</abstract><pub>University of Belgrade, Faculty of Mechanical Engineering</pub><oa>free_for_read</oa></addata></record> |
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| language | srp |
| recordid | cdi_europeana_collections_9200447_BibliographicResource_3000095543323 |
| source | Europeana Collections |
| subjects | aksijalni ventilator anisotropy anizotropnost axial fan invariants invarijante LDA PIV swirl turbulence turbulencija vihor vortex core vrtložno jezgro |
| title | Analysis of the vortex core and turbulence structure behind axial fans in a straight pipe using PIV, LDA and HWA methods |
| url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-01-14T13%3A46%3A25IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-europeana_1GC&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft.genre=dissertation&rft.btitle=Analysis%20of%20the%20vortex%20core%20and%20turbulence%20structure%20behind%20axial%20fans%20in%20a%20straight%20pipe%20using%20PIV,%20LDA%20and%20HWA%20methods&rft.au=%C4%8Cantrak%20%C4%90or%C4%91e&rft.date=2012-07-30&rft_id=info:doi/&rft_dat=%3Ceuropeana_1GC%3E9200447_BibliographicResource_3000095543323%3C/europeana_1GC%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_id=info:pmid/&rfr_iscdi=true |