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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

A study of the pressure drop accompanying flow of a flashing fluid in a circular pipe

Gollobin, Leonard Paul January 2011 (has links)
Typescript, etc. / Digitized by Kansas State University Libraries
2

Holdup and pressure drop in vertical two and three phase flow.

Bhaga, Dahya January 1970 (has links)
No description available.
3

Holdup and pressure drop in vertical two and three phase flow.

Bhaga, Dahya January 1970 (has links)
No description available.
4

Visualization and mathematical modelling of horizontal multiphase slug flow

Gopal, Madan. January 1994 (has links)
Thesis (Ph. D.)--Ohio University, August, 1994. / Title from PDF t.p.
5

Measurement of two-phase flows by phase separation

Whitaker, T. S. January 1992 (has links)
No description available.
6

Modelling of gas-powder-liquid-solid multiphase flow in a blast furnace

Dong, Xuefeng, Materials Science & Engineering, Faculty of Science, UNSW January 2004 (has links)
The ironmaking blast furnace (BF) is a complex reaction vessel involving counter-, coand/ or cross-current flows of gas, powder, liquid, and solids. However, the interactions of these multiphase flows have not been completely understood. The objective of this thesis is to develop a suitable model to simulate the powder flow and accumulation in packed beds and then extend it to numerically investigate the multiphase flow in the furnace. Gas-powder flow in a slot type packed bed has been experimentally studied in order to understand the flow and accumulation behaviour of powder in systems like an ironmaking blast furnace. A variety of variables including gas flowrate, powder flowrate and packing properties have been taken into consideration. It is found that a clear and stable accumulation region can form in the low gas-powder velocity zone at the bottom of the bed. The accumulation region is stable and shows strong hysteresis. The distribution of softening-melting layers in the blast furnace known as the cohesive zone (CZ) is modelled by inserting solid blocks into the bed. The results indicate that the inverse-V cohesive zone shape leads to low powder accumulation within the CZ and at the corner of the bed. A mathematical model is proposed to describe gas-powder flow in a bed packed with particles. The model is the same as the two fluid model developed on the basis of the space-averaged theorem in terms of the governing equations but extended to consider the interactions between gas, powder and packed particles, as well as the static and dynamic holdups of powder. In particular, a method is proposed to determine the boundary between dynamic and stagnant zones with respect to powder phase, i.e. the profile of the powder accumulation zone. The validity of numerical modelling is examined by comparing the predicted and measured distributions of powder flow and accumulation under various flow conditions. With high PCI rate operations, a large quantity of unburned coal/char fines flow together with the gas into the blast furnace. Under some operating conditions, the holdup of fines results in deterioration of furnace permeability and lower production efficiency. Therefore, the proposed model is applied to simulate the powder (unburnt coal/char) flow and accumulation inside the blast furnace when operating with different cohesive zone (CZ) shapes. The results indicate that powder is likely to accumulate at the lower part of W-shaped CZs and the upper part of V- and inverse V-shaped CZs. In addition, for the same CZ shape, a thick cohesive layer can lead to a large pressure drop while the resistance of narrow cohesive layers to gas-powder flow is found to be relatively small. Gas-powder flow in moving beds of solid particles has been numerically investigated, under conditions related to the ironmaking blast furnace and high rate pulverized coal injection. A new correlation, which is formulated to describe static powder holdup in a moving packed bed, is incorporated into the previous mathematical model and applied to a description of gas-powder flow in a blast furnace. Compared with the results of fixed beds, the results show that the solids descent due to the consumption of ore, coke and unburnt char in various regions, together with the non-uniform structural distribution, significantly affects powder flow and accumulation in a blast furnace. Finally, liquid flow is simulated through force balance approach and numerical results are compared with the different liquid inlet distribution under the iron-making blast furnace conditions with gas flow. The results show that the effect of inlet distribution on liquid flow is significant in the upper part of coke region in BF and possible loading and dry zone can be numerically identified. Then, this part of work is incorporated to the developed gas-powder-solid modelling system to investigate the influence of liquid phase on other phases flow in the blast furnace although heat transfer and chemistry are not considered in the model.
7

Pore-scale observations of three-fluid-phase transport in porous media

Brown, Kendra I. 23 August 2012 (has links)
Understanding the transport of three fluid phases through porous media has important applications in subsurface contaminant remediation, oil and gas recovery, and geological CO��� sequestration. Existing transport models may be improved by including physical phenomena that govern fluid flow at the pore scale. In particular, thermodynamic arguments suggest that hysteresis in the capillary pressure-saturation (P[subscript c]-S) relationship may be resolved by including an additional parameter, fluid-fluid interfacial area per volume (a[subscript nw]). Synchrotron-based Computed X-ray Microtomography (CMT) is a method that allows observation of fluid interfaces. Flow experiments were conducted using CMT to investigate uniqueness of the P[subscript c]-S[subscript w]-a[subscript nw] relationship in a porous media system containing three immiscible fluid phases. Drainage and imbibition surfaces were fit to P[subscript c]-S[subscript w]-a[subscript nw] data collected over a limited range of water saturations. The root-mean-square error (RMSE) between the drainage and imbibition surfaces was negligible, indicating that the P[subscript c]-S[subscript w]-a[subscript nw] relationship is unique. These results are a first step in validating the P[subscript c]-S[subscript w]-a[subscript nw] relationship for three-phase porous media systems. In addition, spreading intermediate-phase layers were observed to bring oil and solid into contact, which in the presence of X-rays changed the solid wettability within a relatively short time period. These observations confirm a proposed theoretical scenario that three-phase systems are more susceptible to wettability changes than to two-phase systems due to intermediate-phase spreading behavior. / Graduation date: 2013
8

Multiphase flow in homogeneous and bedded porous media

Schroth, Martin H. 02 February 1996 (has links)
Graduation date: 1996
9

A theoretical and experimental investigation of multi-phase interactions in pure and multicomponent droplet evaporation

Bonuccelli, Courtney Leigh Herring, January 2006 (has links) (PDF)
Thesis (M.S.)--Washington State University, December 2006. / Includes bibliographical references (p. 176-181).
10

A parallel multi-block/multi-physics approach for multi-phase flow in porous media /

Lu, Qin, January 2000 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 144-155). Available also in a digital version from Dissertation Abstracts.

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