{"?xml":{"@version":"1.0"},"edm:RDF":{"@xmlns:dc":"http://purl.org/dc/elements/1.1/","@xmlns:edm":"http://www.europeana.eu/schemas/edm/","@xmlns:wgs84_pos":"http://www.w3.org/2003/01/geo/wgs84_pos","@xmlns:foaf":"http://xmlns.com/foaf/0.1/","@xmlns:rdaGr2":"http://rdvocab.info/ElementsGr2","@xmlns:oai":"http://www.openarchives.org/OAI/2.0/","@xmlns:owl":"http://www.w3.org/2002/07/owl#","@xmlns:rdf":"http://www.w3.org/1999/02/22-rdf-syntax-ns#","@xmlns:ore":"http://www.openarchives.org/ore/terms/","@xmlns:skos":"http://www.w3.org/2004/02/skos/core#","@xmlns:dcterms":"http://purl.org/dc/terms/","edm:WebResource":[{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-KQ6JQ45J/5581c061-091d-4aca-aabc-9664b44a2dcd/PDF","dcterms:extent":"566 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-KQ6JQ45J/0107adc9-3f14-4d46-af12-fdc17a5e8e61/TEXT","dcterms:extent":"36 KB"}],"edm:TimeSpan":{"@rdf:about":"1999-2025","edm:begin":{"@xml:lang":"en","#text":"1999"},"edm:end":{"@xml:lang":"en","#text":"2025"}},"edm:ProvidedCHO":{"@rdf:about":"URN:NBN:SI:doc-KQ6JQ45J","dcterms:isPartOf":[{"@rdf:resource":"https://www.dlib.si/details/URN:NBN:SI:spr-6QOUKQ9A"},{"@xml:lang":"sl","#text":"Strojniški vestnik"}],"dcterms:issued":"2016","dc:creator":["Ahmadi, Ahmad","Keramat, Alireza","Majd, Ali"],"dc:format":[{"@xml:lang":"sl","#text":"letnik:62"},{"@xml:lang":"sl","#text":"številka:nr. 2"},{"@xml:lang":"sl","#text":"str. 105-115"}],"dc:identifier":["ISSN:0039-2480","COBISSID_HOST:14485275","URN:URN:NBN:SI:doc-KQ6JQ45J"],"dc:language":"en","dc:publisher":{"@xml:lang":"sl","#text":"Zveza strojnih inženirjev in tehnikov Slovenije etc."},"dc:subject":[{"@xml:lang":"sl","#text":"časovna zgodovina tlaka"},{"@xml:lang":"sl","#text":"porazdelitev viskoznosti"},{"@xml:lang":"sl","#text":"posplošena newtonska tekočina"},{"@xml:lang":"sl","#text":"prehodni tok v cevi"},{"@xml:lang":"sl","#text":"profil hitrosti"},{"@xml:lang":"sl","#text":"tekočine s strižno odvisnim upadom viskoznosti"}],"dcterms:temporal":{"@rdf:resource":"1999-2025"},"dc:title":{"@xml:lang":"sl","#text":"Investigation of non-Newtonian fluid effects during transient flows in a pipeline|"},"dc:description":[{"@xml:lang":"sl","#text":"A sudden change in the flow rate brings about significant pressure oscillations in the piping system, known as water hammer (fluid hammer). Unsteady flow of a non-Newtonian fluid due to instantaneous valve closure is studied. Power law and Cross models are used to simulate non- Newtonian effects. Firstly, the appropriate governing equations are derived and then, they are solved by a numerical approach. A fourth-order Runge-Kutta scheme is used for the time integration, and the central difference scheme is employed for the spatial derivatives discretization. To verify the proposed mathematical model and numerical solution, a comparison with corresponding experimental results from the literature are made. The results reveal a remarkable deviation in pressure history and velocity profile with respect to the water hammer in Newtonian fluids. The significance of the non-Newtonian fluid behaviour is manifested in terms of the drag reduction and line packing effect observed in the pressure history results. A detailed discussion regarding the fluid viscosity and its shear-stress diagrams are also included"},{"@xml:lang":"sl","#text":"Nenadna sprememba pretoka v cevovodu povzroči velika tlačna nihanja, ki so znana pod imenom vodni (hidravlični) udar. V predstavljeni študiji je bil preučen laminarni prehodni tok nenewtonske tekočine, ki se pojavi zaradi hipnega zapiranja ventila. Za simulacijo nenewtonskih vplivov so bili uporabljeni Crossovi modeli in potenčni zakon. Delo podaja razširitev klasičnega modela vodnega udara, ki se uporablja za preučevanje prehodnih pojavov v newtonski tekočini v ravni elastični cevi, podprti pri ventilu in z zadostnim številom podpor vzdolž cevovoda za preprečitev interakcij med tekočino in konstrukcijo. V ta namen so bile izpeljane kvazidvodimenzionalne enačbe vodnega udara za nenewtonske tekočine in razrešene s primernim numeričnim postopkom na podlagi metode končnih razlik. Za integracijo sistema enačb v času je bila uporabljena shema Runge-Kutta četrtega reda. Prostorski odvodi so bili diskretizirani s centralno diferenčno shemo. Za odpravo numeričnih nihanj so bili dodani disipativni členi drugega reda. Ti členi učinkujejo samo v območju velikih gradientov, v gladkih območjih pa so praktično izključeni"}],"edm:type":"TEXT","dc:type":[{"@xml:lang":"sl","#text":"znanstveno časopisje"},{"@xml:lang":"en","#text":"journals"},{"@rdf:resource":"http://www.wikidata.org/entity/Q361785"}]},"ore:Aggregation":{"@rdf:about":"http://www.dlib.si/?URN=URN:NBN:SI:doc-KQ6JQ45J","edm:aggregatedCHO":{"@rdf:resource":"URN:NBN:SI:doc-KQ6JQ45J"},"edm:isShownBy":{"@rdf:resource":"http://www.dlib.si/stream/URN:NBN:SI:doc-KQ6JQ45J/5581c061-091d-4aca-aabc-9664b44a2dcd/PDF"},"edm:rights":{"@rdf:resource":"http://rightsstatements.org/vocab/InC/1.0/"},"edm:provider":"Slovenian National E-content Aggregator","edm:intermediateProvider":{"@xml:lang":"en","#text":"National and University Library of Slovenia"},"edm:dataProvider":{"@xml:lang":"sl","#text":"Univerza v Ljubljani, Fakulteta za strojništvo"},"edm:object":{"@rdf:resource":"http://www.dlib.si/streamdb/URN:NBN:SI:doc-KQ6JQ45J/maxi/edm"},"edm:isShownAt":{"@rdf:resource":"http://www.dlib.si/details/URN:NBN:SI:doc-KQ6JQ45J"}}}}