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Full-Text Articles in Engineering
Modeling, Numerical Analysis, And Predictions For The Detonation Of Multi-Component Energetic Solids, Michael Wayne Crochet
Modeling, Numerical Analysis, And Predictions For The Detonation Of Multi-Component Energetic Solids, Michael Wayne Crochet
LSU Doctoral Dissertations
Metal powders are often used as an additive to conventional high explosives to enhance the post-detonation blast wave. Piston-impact simulations are commonly utilized to predict performance metrics such as detonation speed and strength, as well as assessing the impact and shock sensitivity of these materials. The system response is strongly influenced by the initial particle size distribution and material composition. Multiphase continuum models have been routinely applied at the macroscale to characterize the detonation of solid high explosives over engineering length scales. Current models lack a description of the physically permissible constitutive relations for mass transfer due to general chemical …
Flow And Distribution Of Water In Fractional Wettability Unsaturated Porous Media, Zaydoun Turkey Abusalem
Flow And Distribution Of Water In Fractional Wettability Unsaturated Porous Media, Zaydoun Turkey Abusalem
LSU Doctoral Dissertations
In recent years, interest in fluid flow and transport in the unsaturated zone has gained more attention, due to growing concerns that the quality of the subsurface environment is adversely affected by agricultural, industrial, and municipal activities. The wettability properties (e.g., water repellency) of soil in the unsaturated zone play an important role in determining fluid movement and ultimate distributions. A number of studies have shown that preferential flow and spatially variable moisture content is likely to occur in water repellant soils. Development of appropriate constitutive relations for numerical modeling becomes even more difficult in systems that contain water repellant …
Modeling The Flow Of Non-Newtonian Fluids In Packed Beds At The Pore Scale, Matthew Balhoff
Modeling The Flow Of Non-Newtonian Fluids In Packed Beds At The Pore Scale, Matthew Balhoff
LSU Doctoral Dissertations
Flow and transport in porous media are important in many science and engineering applications such as composite materials, subsurface water contamination, packed-bed reactors, and enhanced oil recovery. The general approach to modeling such processes is at the continuum scale. Semi-empirical expressions, such as Darcy's law, are substituted for velocity in the continuity equation, which is then coupled with a momentum, mass, and energy balance. While a continuum approach is acceptable in some cases, additional modeling is required for certain non-linear flows, such as multi-phase flows, inertial flows, non-Newtonian flows, and reactive flows. Pore-scale modeling is a first-principles approach to modeling …
Stability, Transport And Applications Of Polyaphrons In Porous Media, Le Yan
Stability, Transport And Applications Of Polyaphrons In Porous Media, Le Yan
LSU Doctoral Dissertations
Polyaphrons are a kind of macroemulsion. The most distinctive feature of polyaphrons is their high stability. On the other hand, certain polyaphrons can be effectively destabilized by multivalent ions. In this dissertation, we devise a novel procedure that utilizes the fact that polyaphrons can be destabilized by certain ions to deliver light chemicals to lower the density of dense non-aqueous phase liquid (DNAPL) contaminants in situ. We first investigate how the stability of diluted polyaphrons is affected by the properties of the continuous phase. We find that polyaphrons can be destabilized by a low concentration of Al3+ or Ca2+ in …
The Effects Of Local Hydrodynamics On Mass Transfer In Disordered Porous Media, Gang Guo
The Effects Of Local Hydrodynamics On Mass Transfer In Disordered Porous Media, Gang Guo
LSU Doctoral Dissertations
Interfacial mass transfer in disordered media was studied experimentally and numerically. The dissolution of solid benzoic acid spheres in packed columns showed the existence of spatial variations in mass transfer coefficients in monodisperse and polydisperse packings at the same overall Peclet number. The concept of a local Peclet number (single-particle average) was introduced to quantify the effect of local hydrodynamics on local mass transfer. Correlations between Sherwood number and Peclet number having the form Shi=A·(xiPe)m were used to quantify data from various sites in each packing. These experiments also showed that the exponent m varies …
Extraction Of Physically-Realistic Pore Network Properties From Three-Dimensional Synchrotron Microtomography Images Of Unconsolidated Porous Media, Riyadh Ibrahim Al-Raoush
Extraction Of Physically-Realistic Pore Network Properties From Three-Dimensional Synchrotron Microtomography Images Of Unconsolidated Porous Media, Riyadh Ibrahim Al-Raoush
LSU Doctoral Dissertations
Algorithms were implemented to obtain high resolution three-dimensional images using synchrotron microtomography. Morphological algorithms were developed to extract physically-realistic pore-network structure from unconsolidated porous media systems imaged using synchrotron microtomography. The structure can be used to correlate pore-scale phenomena with the pore structure and can also be incorporated into a pore-network model to verify existing models, understand, or predict transport and flow processes and phenomena in complex porous media systems. The algorithms are based on the three-dimensional skeletonization of the pore space in the form of nodes connected to paths. Dilation algorithms were developed to generate inscribed spheres on the …