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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Drag reduction in cocurrent horizontal natural gas-hexane pipe flow /

Dowling, Russell Hugh. January 1976 (has links)
Thesis (Ph.D.)--University of Tulsa, 1976. / Bibliography: leaves 85-87.
2

Velocity profile in confined elliptic fractures

Pack, Stephen Ronald, January 1900 (has links)
Thesis (M.S.)--West Virginia University, 1998. / Title from document title page. "December 1998." Document formatted into pages; contains x, 78 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 57-58).
3

The design of skin friction gages for measurements in high-speed, short-duration flows /

Busic, John F., January 1992 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaf 113). Also available via the Internet.
4

The measurement of skin friction and static pressure in subsonic flow

White, J. K. January 1965 (has links)
No description available.
5

Dilute solution molecular characterization and drag reducation studies of high molecular weight polyethylene oxide

Jones, Brian Dion 13 December 2001 (has links)
The molecular weight distributions of two high molecular weight (M[subscript w]>>1 million) polyethylene polymers, WSR-308 and WSR-301, were characterized with gel permeation chromatography (GPC) coupled with a multi-angle laser light scattering detector (MALLS). The M[subscript w] of the WSR-308 was found to be 5.10x10⁶ g/mol with a molecular weight range from about 1 million g/mol to as high as 10 million g/mol. The M[subscript w] of the WSR-301 was found to be 3.16x10⁶ g/mol with the lowest molecular weight about 400,000 g/mol while the highest molecular weight component may have been as high as 8 million g/mol. Attempts to measure the M[subscript w] of the two polymers using static light scattering (SLS) techniques proved to be difficult. In conjunction with these studies, drag reduction and shear degradation studies of the two polymers in water were also conducted. Solutions of the two polymers, ranging from 1 to 10 ppm including mixtures of the two, were tested in a pipe-flow apparatus to obtain friction factor and %DR data. In every case, the greater the concentration and/or the molecular weight of the polymer, the greater the drag reduction effects. Additionally, the higher molecular weight polymer and mixtures with a greater weight percentage of the higher molecular weight polymer were found to shear degrade less quickly than otherwise. A unique point along the maximum drag reduction asymptote (MDA) termed the "divergence point" was a focus of this study and an energy model based on frictional losses correlates well to the data. The correlation developed here relates the difference in frictional losses between the solvent by itself and the polymer solution directly to the mass concentration and molecular weight of the polymer. This frictional difference was proportional to the product of the mass concentration and molecular weight where both quantities were to approximately the first power. / Graduation date: 2002
6

Analysis of viscous drag reduction and thermal transport effects for microengineered ultrahydrophobic surfaces /

Davies, Jason W., January 2006 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2006. / Includes bibliographical references (p. 105-106).
7

Investigation of relationships among microstructure, rheology, drag reduction and heat transfer of drag reducing surfactant solutions /

Qi, Yunying January 2002 (has links)
No description available.
8

Flow resistance of large-scale roughness in mountain rivers of the Western Cape

Malan, Jan Gottlieb 12 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: This investigation arose out of the pressing need for alternatives to ineffective existing methodologies for low flow measurement in boulder bed rivers, with particular focus on the mountain streams in the Western Cape. Both empirical and mathematical verification were regarded as important if progress was to be made towards identifying a suitable approach. Historically the inability to determine the frictional effect of the streambed on the flow rate has been a major obstacle limiting the accuracy of flow calculations. From literature, the most likely relationship appears to be a power function, utilising hydraulic variables derived from physical parameters characteristic of a section of stream. Local Western Cape data was thus collected from various typical mountain streams, so that relevant analysis could be done. Testing of existing equations from literature sources on this set of data revealed limited applicability. Subsequent empirical experimentation has shown that particle size is a dominant variable in determining boulder bed flow resistance under low flow conditions. A mathematical approach was sought to provide a more suitable base for a locally applicable formula. Sediment transport theory, based on simple power conservation laws, was successfully implemented, partially bridging the gap between the applications for sand bed and boulder bed flow conditions respectively. After a certain degree of empirical adjustment, an equation form was finalised that is believed to be the most suitable for Western Cape mountain streams, with definite potential for wider application, provided further research is done. / AFRIKAANSE OPSOMMING: Hierdie ondersoek spruit uit die dringende behoefte aan bruikbare alternatiewe vir bestaande laagvloei meetmetodes in riviere met bodems bestaande uit spoelklip, met spesifieke klem op die bergstrome van die Wes Kaap. Dit is as belangrik beskou om beide empiriese en wiskundige bevestiging te vind vir 'n verbeterde metode. Histories is die akkuraatheid van vloeitempo berekeninge hoofsaaklik beperk deur die onvoorspelbaarheid van die ruheidseffek van die rivierbodem op die vloei. Uit bestaande literatuur blyk dit dat die mees geskikte verwantskap waarskynlik 'n magsfunksie is, wat saamgestel is uit hidrouliese veranderlikes verkry vanaf fisiese parameters kenmerkend aan die spesifieke riviersnit. Plaaslike Wes-Kaapse data is dus versamelop verskeie tipiese bergstrome in die gebied sodat geskikte ontledings gedoen kon word. Verskeie bestaande formules is getoets teen hierdie stel data en ongeskik gevind vir direkte aanwending. Empiriese toetse het gevolg en getoon dat partikel grootte 'n dominante invloed het op die vloeiweerstand van spoelklip bodems onder laagvloei omstandighede. 'n Wiskundige benadering is daarna gevolg om 'n beter basis te verskaf waaruit 'n plaaslik bruikbare vergelyking kon volg. Sedimentvervoer beginsels, wat gebaseer is op basiese drywingsteorie, is suksesvol aangewend vir hierdie doel, en het in 'n mate die gaping tussen aanwending op sand en klip bodems oorbrug. Na afloop van empiriese verstelling is 'n formule gefinaliseer wat beskou word as die mees geskikte vir Wes-Kaapse bergstrome, maar wat ook die potensiaal besit vir wyer aanwending, mits verdere navorsing gedoen sou word.
9

Investigating flow resistance for uniform and random rough surfaces. / 均勻和隨機粗糙表面的水流阻力研究 / CUHK electronic theses & dissertations collection / Jun yun he sui ji cu cao biao mian de shui liu zu li yan jiu

January 2011 (has links)
Qin, Jie. / "November 2010." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 162-173). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
10

effects of polymer concentration on turbulent drag reduction. / 聚合物濃度對湍流減阻的影響 / The effects of polymer concentration on turbulent drag reduction. / Ju he wu nong du dui tuan liu jian zu de ying xiang

January 2011 (has links)
Leung, Chung Yin = 聚合物濃度對湍流減阻的影響 / 梁頌賢. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 106-108). / Abstracts in English and Chinese. / Leung, Chung Yin = Ju he wu nong du dui tuan liu jian zu de ying xiang / Liang Songxian. / Abstract --- p.i / 概要 --- p.iii / Acknowledgements --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The phenomenon of polymer drag reduction --- p.1 / Chapter 1.2 --- The Phenomenology of drag reduction --- p.9 / Chapter 1.3 --- A recent theory --- p.19 / Chapter 2 --- Review of a recent theory of drag reduction --- p.21 / Chapter 2.1 --- The balance equations --- p.21 / Chapter 2.2 --- Estimating the average terms --- p.26 / Chapter 2.2.1 --- Average terms for flexible polymers --- p.27 / Chapter 2.2.2 --- Average terms for rodlike polymers --- p.32 / Chapter 2.3 --- Solving the balance equations --- p.34 / Chapter 3 --- Behavior near the maximum drag reduction asymptote --- p.42 / Chapter 4 --- Reduction of drag at small concentrations --- p.57 / Chapter 5 --- Velocity profiles and friction factor relations --- p.61 / Chapter 5.1 --- Newtonian flow without polymer --- p.61 / Chapter 5.2 --- Flow at high polymer concentration --- p.63 / Chapter 5.3 --- Flow at intermediate concentration --- p.68 / Chapter 6 --- The Reynolds stress profile --- p.88 / Chapter 7 --- Percentage drag reduction --- p.95 / Chapter 8 --- Conclusion and future work --- p.104 / Bibliography --- p.106

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