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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.
11

Mechanism and analysis of multiphase flow through soil

Elmonayeri, Diaa S. (Diaa Salah), 1950- January 1983 (has links)
Multiphase flow in porous media is a wide-ranging phenomenon, covering such topics as the motion of immiscible fluids, where the interaction with the medium is by exchange of heat and/or mass between phases, to fluid-solid phase flow accompanied by clogging and leaching. The present study is limited to the flow of immiscible fluids (oil and surfactant), where fine solids (clay) migration occurs during the motion. It is divided into two parts: (a) experimental and (b) theoretical. / The experimental investigations have been performed in order to evaluate: (a) the factors (e.g., porosity, temperature and injection pressure) that affect the injected surfactant flow rate through oil/soil mixtures, (b) the role of clay mineral concentration on the uptake and displacement of oil by the injected surfactant, (c) the portion of the oil displaced by the injected surfactant in the medium, under the testing conditions, (d) the effect of injection head on the rate of oil uptake during the injection process. / The theoretical analysis leads to a new diffusion model which accounts for the simultaneous movement of oil, fines and surfactant. The conclusion to be drawn from this part is that the new simplified model, together with further refinement, lead to a better understanding of the behaviour and prediction of the multiphase flow through a porous medium.
12

Multiphase flow in packed beds with special reference to ironmaking blast furnace

Chen, Matthew Lidong, Materials Science & Engineering, Faculty of Science, UNSW January 2008 (has links)
Multi-phase flows can be found in a range of processes in vanous industries. Ironrnaking blast furnace is one of the typical examples. With high pulverized coal injection rates, complete combustion within the raceway of blast furnace becomes difficult, giving rise to a large amount of powder flow together with gases into the furnace. Thus, the performance of a modern blast furnace with high PCI strongly depends on the characteristics of a multiphase system which involves gas, powder, and liquid superimposed on the motion of solid particles. For this multiphase flow system, the solid (coke, sinter/pellets, etc) movement and liquids (hot metal and slag) and powders (unbumt coal and coke ash) accumulation in the lower region of the furnace are believed to play an important role. This thesis presents an experimental study focus on quantifying the hydrodynamics of gas-powder and gas-powder-liquid flows through packed beds with special reference to blast furnace. The effects of process variables including fluid flowrate and some material properties on powder hold-up, pressure gradient and phase interaction are examined. An experimental study of the hydrodynamics of gas-powder flow in packed beds has been carried out. Glass powder and spherical/non-spherical particles are used to simulate pulverized coal and coke particle respectively. It is found that solid motion, powder flowrate and particle spericity affect powder hold-up and pressure gradient significantly. New correlations are proposed for static and dynamic powder hold-ups to account for these effects based on experimental results. A hydrodynamic model is proposed for gas-powder flow in packed beds with spherical and non-spherical particles. Incorporation these correlations and porosity function into the existed Fanning and Ergun equations, the pressure gradients in fixed and moving beds can be reasonably estimated. The gas-powder-liquid flow through the moving beds is studied. The effects of fluid variables and some material properties on total powder hold-up and pressure gradients have been examined experimentally within the so-called operational regime. The normal and non-wetting treated glass beads, glass powder and water or mixture of water and glycerin are used to simulate coke, pulverized coal and hot metal/slag in a blast furnace. The results indicates that steady-state gas-powder-liquid flow in moving packed beds can be achieved under certain flow conditions since particle motion gives main contribution while it provides a higher bed porosity, enhances powder and liquid flow and removes the accumulation of the powder. The fluid variables and liquid viscosity significantly affect the total powder hold-up and hence pressure gradient but the wettability does not. Based on the experimental results, new correlations for powder hold-up and pressure gradient are proposed for blast furnace modelling in terms of dimensionless number of flowrates for different phases. Incorporation of these correlations and the existed empirical correlations of phase interactions, a hydrodynamic model is proposed to quantify the interaction force between liquid and powder. The results show that this force plays an important role for stable gas-powder-liquid flow in moving beds though it is ignored by most of the previous researchers.
13

History matching by simultaneous calibration of flow functions

Barrera, Alvaro Enrique, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.
14

Time-dependent boundary conditions for multiphase flow

Olsen, Robert, January 1900 (has links)
Diss., 2004 / Title from document title page. Includes bibliographical references. Available in PDF format via the World Wide Web.
15

Direct numerical simulation of swirling flows using the front tracking method

Terdalkar, Rahul J. January 2007 (has links)
Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: evolution of bubble, spinning drop tensiometer, front tracking. Includes bibliographical references (leaves 47-49 ).
16

Effect of a drag reducing agent on pressure drop and flow regime transitions in multiphase horizontal low pressure pipelines

Vancko, Robert M. January 1997 (has links)
Thesis (M.S.)--Ohio University, March, 1997. / Title from PDF t.p.
17

A study of slug flow characteristics in large diameter horizontal multiphase pipelines

Maley, Lisa. January 1997 (has links)
Thesis (M.S.)--Ohio University, June, 1997. / Title from PDF t.p.
18

Experimental study of corrosion rate and slug flow characteristics in horizontal, multiphase pipeline

Zhou, Xianling. January 1993 (has links)
Thesis (M.S.)--Ohio University, August, 1993. / Title from PDF t.p.
19

Study of two and three-phase flows in large diameter horizontal pipelines

Malhotra, Ajay. January 1995 (has links)
Thesis (M.S.)--Ohio University, November, 1995. / Title from PDF t.p.
20

Study and modeling of sweet corrosion of multiphase mixtures in horizontal pipelines

Kanwar, Sumeet. January 1994 (has links)
Thesis (M.S.)--Ohio University, June, 1994. / Title from PDF t.p.

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