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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.
71

The orientation state of semi-dilute rigid fibre suspensions in a linearly contracting channel

Krochak, Paul Joseph 05 1900 (has links)
This work investigates the effects of long range hydrodynamic fibre-fibre interactions on the orientation state of a semi-dilute, rigid fibre suspension flowing through a linear contracting channel under laminar flow conditions. The effects of fibre-fibre interactions are modeled mathematically, the governing equations solved numerically and the predicted results compared with experimental observations. The theoretical model is based on the assumption that the orientation state of the suspension can be completely described by a probability distribution function and that fibre-fibre interactions are random in nature, thus giving rise to a diffusion-type process. The orientation distribution evolves spatially according to a Fokker-Plank type equation using closure equations for the rotary diffusion coefficient advanced by either (i) Folgar and Tucker (J. Reinforced Plast. Comp. 3 98–119 1984) or (ii) Koch (Phys. Fluids 7(8) 2086–2088 1995). Each of these two closure models for the rotary diffusion coefficient contains an unknown empirical constant that must be determined from experiments. These were fit to experimental data along the central streamline of the contraction as a function of fibre concentration. The diffusion coefficient was found to first increase with increasing suspension concentration up to a maximum, and then decrease with concentration above this point. This non-monotonic behavior was attributed to fibre flocculation, a mechanism not considered in the relationships for the rotary diffusion coefficient. The theoretical model is then extended to predict fibre orientation over the entire plane of the contraction and the two-way momentum coupling between the fluid and fibre phases were investigated numerically. The results show that the structure of the flow field within the contraction is significantly altered when the fibre phase is considered, demonstrating the non-negligible effect of the momentum exchange between the two phases. Comparison is made between the predicted orientation state of the suspension with experimental observations over the contraction plane. Good agreement was found between the model predictions and the experimental observations except in a small region near the solid boundaries. These near wall discrepancies were attributed to an inability to correctly handle the wall boundary conditions in the fibre orientation model.
72

The orientation state of semi-dilute rigid fibre suspensions in a linearly contracting channel

Krochak, Paul Joseph 05 1900 (has links)
This work investigates the effects of long range hydrodynamic fibre-fibre interactions on the orientation state of a semi-dilute, rigid fibre suspension flowing through a linear contracting channel under laminar flow conditions. The effects of fibre-fibre interactions are modeled mathematically, the governing equations solved numerically and the predicted results compared with experimental observations. The theoretical model is based on the assumption that the orientation state of the suspension can be completely described by a probability distribution function and that fibre-fibre interactions are random in nature, thus giving rise to a diffusion-type process. The orientation distribution evolves spatially according to a Fokker-Plank type equation using closure equations for the rotary diffusion coefficient advanced by either (i) Folgar and Tucker (J. Reinforced Plast. Comp. 3 98–119 1984) or (ii) Koch (Phys. Fluids 7(8) 2086–2088 1995). Each of these two closure models for the rotary diffusion coefficient contains an unknown empirical constant that must be determined from experiments. These were fit to experimental data along the central streamline of the contraction as a function of fibre concentration. The diffusion coefficient was found to first increase with increasing suspension concentration up to a maximum, and then decrease with concentration above this point. This non-monotonic behavior was attributed to fibre flocculation, a mechanism not considered in the relationships for the rotary diffusion coefficient. The theoretical model is then extended to predict fibre orientation over the entire plane of the contraction and the two-way momentum coupling between the fluid and fibre phases were investigated numerically. The results show that the structure of the flow field within the contraction is significantly altered when the fibre phase is considered, demonstrating the non-negligible effect of the momentum exchange between the two phases. Comparison is made between the predicted orientation state of the suspension with experimental observations over the contraction plane. Good agreement was found between the model predictions and the experimental observations except in a small region near the solid boundaries. These near wall discrepancies were attributed to an inability to correctly handle the wall boundary conditions in the fibre orientation model.
73

A coupled wellbore/reservoir simulator to model multiphase flow and temperature distribution

Pourafshary, Peyman, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.
74

Low differential pressure and multiphase flow measurements by means of differential pressure devices

Ruiz, Justo Hernandez. January 1900 (has links)
Thesis (Ph.D.)--Texas A & M University, 2004. / Title from caption (viewed on Feb. 8, 2008). Title from document title page. Includes bibliographical references. Available in PDF format via the World Wide Web.
75

A study of drag reducing agents in multiphase flow in large diameter horizontal pipelines

Tullius, Lisa. January 2000 (has links)
Thesis (Ph. D.)--Ohio University, June, 2000. / Title from PDF t.p.
76

Inhibition mechanisms of corrosion inhibitors in multiphase flow conditions using electrochemical techniques

Chen, Yue. January 2000 (has links)
Thesis (Ph. D.)--Ohio University, March, 2000. / Title from PDF t.p.
77

CO₂ corrosion mechanistic modeling in horizontal slug low

Wang, Hongwei. January 2002 (has links)
Thesis (Ph. D.)--Ohio University, 2002. / Title from PDF t.p.
78

Development of multiphase flow metering set-up utilizing coriolis meters

Al-Taweel, Ahmed Baqer. January 1997 (has links) (PDF)
Thesis (M.S.)--King Fahd University of Petroleum and Minerals, 1997 / Title from document title page. Includes bibliographical references. Available in PDF format via the World Wide Web.
79

Effect of gas density on corrosion in horizontal multiphase slug flow at high temperatures and pressures

Krishnamoorthy, Vijay. January 1997 (has links)
Thesis (M.S.)--Ohio University, November, 1997. / Title from PDF t.p.
80

Study of carbon dioxide corrosion of carbon steel pipes in multiphase systems

Vuppa, Anil Kumar. January 1994 (has links)
Thesis (M.S.)--Ohio University, August, 1994. / Title from PDF t.p.

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