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Computational Engineering Commons

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2013

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Articles 1 - 30 of 60

Full-Text Articles in Computational Engineering

Experimental Investigation Of Mist Film Cooling And Feasibility Study Of Mist Transport In Gas Turbines, Reda M. Ragab Dec 2013

Experimental Investigation Of Mist Film Cooling And Feasibility Study Of Mist Transport In Gas Turbines, Reda M. Ragab

University of New Orleans Theses and Dissertations

In the modern advanced gas turbines, the turbine inlet temperature may exceed 1500°C as a requirement to increase power output and thermal efficiency. Therefore, it is imperative that the blades and vanes are cooled so they can withstand these extreme temperatures. Film cooling is a cooling technique widely used in high-performance gas turbines. However, the film cooling effectiveness has almost reached plateau, resulting in a bottleneck for continuous improvement of gas turbines' efficiency.

In this study, an innovative cooling scheme, mist film cooling is investigated through experiments. A small amount of tiny water droplets with an average diameter about ...


Numerical Modelling Of Downburst Interaction With Bluff Body, Aditi Jog Dec 2013

Numerical Modelling Of Downburst Interaction With Bluff Body, Aditi Jog

Electronic Thesis and Dissertation Repository

The objective of this study is to investigate the interaction of a bluff body with a downburst flow. Numerical investigation of the flow field using CFD analysis was carried out for three different downburst sizes (h/d=1, 2, 4) under suitable boundary conditions subjected to constant jet velocity. The downburst-structure interaction study was conducted for two jet diameters (h/d=1 and 4) and two radial locations from the downburst center.

The results showed that the downburst size greatly dominates the intensity of the flow. The largest downburst resulted in the highest velocity magnitude near the ground and also ...


Improving Safety In Medical Devices From Concept To Retirements, Martin Mchugh, Fergal Mccaffery, Silvana Macmahon, Anita Finnega Dec 2013

Improving Safety In Medical Devices From Concept To Retirements, Martin Mchugh, Fergal Mccaffery, Silvana Macmahon, Anita Finnega

Books/Book Chapters

No abstract provided.


Adsorption And Diffusion Of Gases In Nano-Porous Materials, Nethika Sahani Suraweera Dec 2013

Adsorption And Diffusion Of Gases In Nano-Porous Materials, Nethika Sahani Suraweera

Doctoral Dissertations

In this work, a systematic computational study directed toward developing a molecular-level understanding of gas adsorption and diffusion characteristics in nano-porous materials is presented. Two different types of porous adsorbents were studied, one crystalline and the other amorphous. Physisorption and diffusion of hydrogen in ten iso-reticular metal-organic frameworks (IRMOFs) were investigated. A set of nine adsorbents taken from a class of novel, amorphous nano-porous materials composed of spherosilicate building blocks and isolated metal sites was also studied, with attention paid to the adsorptive and diffusive behavior of hydrogen, methane, carbon dioxide and their binary mixtures. Both classes of materials were ...


Bayesian Dictionary Learning For Single And Coupled Feature Spaces, Li He Dec 2013

Bayesian Dictionary Learning For Single And Coupled Feature Spaces, Li He

Doctoral Dissertations

Over-complete bases offer the flexibility to represent much wider range of signals with more elementary basis atoms than signal dimension. The use of over-complete dictionaries for sparse representation has been a new trend recently and has increasingly become recognized as providing high performance for applications such as denoise, image super-resolution, inpaiting, compression, blind source separation and linear unmixing. This dissertation studies the dictionary learning for single or coupled feature spaces and its application in image restoration tasks. A Bayesian strategy using a beta process prior is applied to solve both problems.

Firstly, we illustrate how to generalize the existing beta ...


Effects Of Data Resolution And Human Behavior On Large Scale Evacuation Simulations, Wei Lu Dec 2013

Effects Of Data Resolution And Human Behavior On Large Scale Evacuation Simulations, Wei Lu

Doctoral Dissertations

Traffic Analysis Zones (TAZ) based macroscopic simulation studies are mostly applied in evacuation planning and operation areas. The large size in TAZ and aggregated information of macroscopic simulation underestimate the real evacuation performance. To take advantage of the high resolution demographic data LandScan USA (the zone size is much smaller than TAZ) and agent-based microscopic traffic simulation models, many new problems appeared and novel solutions are needed. A series of studies are conducted using LandScan USA Population Cells (LPC) data for evacuation assignments with different network configurations, travel demand models, and travelers’ compliance behavior.

First, a new Multiple-Source-Nearest-Destination Shortest Path ...


Action Potential Simulation Of The Hirudo Medicinalis's Retzius Cell In Matlab, Zechari Ryan Tempesta Dec 2013

Action Potential Simulation Of The Hirudo Medicinalis's Retzius Cell In Matlab, Zechari Ryan Tempesta

Master's Theses and Project Reports

Modification of Hodgkin and Huxley’s experimentally derived set of nonlinear differential equations was implemented to accurately simulate the action potential of the Hirudo Medicinalis’s Retzius cell in MATLAB under analogous conditions to those found in the Retzius cell environment. The voltage-gated sodium and potassium channel responses to changes in membrane potential, as experimentally determined by Hodgkin and Huxley, were manipulated to suit simulation parameters established by electrophysiological Retzius cell recordings. Application of this methodology permitted additional accurate simulation of the Hirudo Medicinalis’s P cell under analogous conditions to those found in the P cell environment. Further refinement ...


Higher-Order Petrov-Galerkin Methods For Analysis Of Antennas, Xueying Zhang Dec 2013

Higher-Order Petrov-Galerkin Methods For Analysis Of Antennas, Xueying Zhang

Masters Theses and Doctoral Dissertations

A temporally and spatially high-order accurate Petrov-Galerkin finite-element method is applied to the analysis of several antenna configurations. The method obtains numerical solutions of Maxwell's equations in the time domain using implicit time stepping and introduces energy into the domain using a Gaussian pulse to allow frequency-domain parameters to be computed over a range of frequencies with a single time-dependent solution. Verification cases for a monopole antenna and a microstrip patch antenna are used to examine the accuracy of the algorithm. Effects of varying antenna parameters on subsequent performance metrics are discussed based on the results from the simulations ...


A New Software Framework For Unstructured Mesh Representation And Manipulation, Craig R. Tanis Dec 2013

A New Software Framework For Unstructured Mesh Representation And Manipulation, Craig R. Tanis

Masters Theses and Doctoral Dissertations

This research presents a unique new software framework for representing and manipulating unstructured meshes in parallel, for use in modern scientific simulation codes. Due to the central nature of the unstructured mesh, this framework provides a variety of functionality, desirable throughout the lifecycle of an application, such as IO, parallel partitioning, phantom node data updates, adaptive refinement, derefinement and load balancing. What makes the framework unique is a focus on generality: like a database, the user provides a programmatic schema defining the structure of the mesh, including topological descriptions of the valid mesh entities. The system extracts adjacency information from ...


Validation Of Interpolative Interfaces For Rotorcraft Applications, Adam L. Cofer Dec 2013

Validation Of Interpolative Interfaces For Rotorcraft Applications, Adam L. Cofer

Masters Theses and Doctoral Dissertations

The study uses computational methods to simulate fluid flow on the NASA ROBIN helicopter model and on a simplified rotor geometry previously tested at Mississippi State. The ROBIN model and the rotor are run using an unstructured grid. Results from the Tenasi flow solver are compared against both simulated and wind tunnel data. Tenasi is an unstructured, Reynolds Averaged Navier-Stokes (RANS) solver developed at the SimCenter: National Center for Computational Engineering, located at the University of Tennessee at Chattanooga. Steady-state results for the isolated ROBIN fuselage and unsteady results for both fuselage and rotor systems are computed. In the unsteady ...


Stabilized Finite Elements For Compressible Turbulent Navier-Stokes, Jon Taylor Erwin Dec 2013

Stabilized Finite Elements For Compressible Turbulent Navier-Stokes, Jon Taylor Erwin

Masters Theses and Doctoral Dissertations

In this research a stabilized finite element approach is utilized in the development of a high-order flow solver for compressible turbulent flows. The Reynolds averaged Navier-Stokes (RANS) equations and modified Spalart-Almaras (SA) turbulence model are discretized using the streamline/upwind Petrov-Galerkin (SUPG) scheme. A fully implicit methodology is used to obtain steady state solutions or to drive unsteady problems at each time step. Order of accuracy is assessed for inviscid and viscous flows in two and three dimensions via the method of manufactured solutions. Proper treatment of curved surface geometries is of vital importance in high-order methods, especially when high ...


Extension Of A High-Order Petrov-Galerkin Implementation Applied To Non-Radiating And Radar Cross Section Geometries, William L. Shoemake Dec 2013

Extension Of A High-Order Petrov-Galerkin Implementation Applied To Non-Radiating And Radar Cross Section Geometries, William L. Shoemake

Masters Theses and Doctoral Dissertations

Capabilities of a high-order Petrov-Galerkin solver are expanded to include N-port systems. Tait-Bryan angles are employed to launch electro-magnetic waves in arbitrary directions allowing off axis ports to be driven. The transverse-electric (TE) formulation is added allowing waveguide geometries to be driven directly. A grid convergence study is performed on a coax-driven waveguide system. Physical data are matched to a hybrid-T junction (magic-T) electromagnetic waveguide structure to verify the TE driving formulation along with the Tait-Bryan angles and modified post-processing routines. A simple sphere case is used to exercise the radar cross section (RCS) routines and to examine the benefits ...


2-D Cfd Design Of The Cross-Sectional Shape Of Arterial Stents, Kristen Karman Dec 2013

2-D Cfd Design Of The Cross-Sectional Shape Of Arterial Stents, Kristen Karman

Masters Theses and Doctoral Dissertations

An approach for desigining arterial stents to maximize wall shear stress is presented. A cost equation to maximize wall shear stress is derived and then inverted into a minimization problem for the optimizer. A 2-D mixed-element finite-volume scheme for solving the compressible Navier-Stokes equations is implemented. A paramaterization of the cross- sectional shape of the stent wire using Hicks-Henne functions is described. The strategies used in the commercial optimization software, DAKOTA, to minimize the cost equation are described. The solver is validated using well known fluid flow test cases and is shown to match other published computed results for bloodflow ...


Physics-Based Point Placement By Particle Dynamics Simulation, Philip Wesley Fackler Dec 2013

Physics-Based Point Placement By Particle Dynamics Simulation, Philip Wesley Fackler

Masters Theses and Doctoral Dissertations

A physics-based approach to point cloud distribution for mesh generation is investigated using inter-nodal attraction and repulsion forces based on the Lennard-Jones pair potential and a simplified particle dynamics simulation. This method produces smooth distributions of points which accurately correspond to desired scalar spacing fields. Resulting point distributions are triangulated using Lawson's algorithm and the quality of these resulting meshes is measured, demonstrating the effectiveness of the approach. Several features planned for future development for increasing the robustness and versatility of the proposed method are discussed.


Artist-Driven Fracturing Of Polyhedral Surface Meshes, Tyler Casella Dec 2013

Artist-Driven Fracturing Of Polyhedral Surface Meshes, Tyler Casella

Master's Theses and Project Reports

This paper presents a robust and artist driven method for fracturing a surface polyhedral mesh via fracture maps. A fracture map is an undirected simple graph with nodes representing positions in UV-space and fracture lines along the surface of a mesh. Fracture maps allow artists to concisely and rapidly define, edit, and apply fracture patterns onto the surface of their mesh.

The method projects a fracture map onto a polyhedral surface and splits its triangles accordingly. The polyhedral mesh is then segmented based on fracture lines to produce a set of independent surfaces called fracture components, containing the visible surface ...


Leveraging Apple Remote Desktop To Facilitate Classroom Critiques Of Digital Projects, Jerry C. Schnepp Nov 2013

Leveraging Apple Remote Desktop To Facilitate Classroom Critiques Of Digital Projects, Jerry C. Schnepp

Visual Communication and Technology Education Faculty Publications

Classroom critiquing of visual projects is an essential exercise to help students refine their work. Usually, instructors display student work on a large screen so that the class can offer comments and suggestions. However, problems arise because critiques are often mired by ambiguous or misunderstood language. Sometimes students are better shown than told. This presentation demonstrates how Apple Remote Desktop (ARD) can be used to project the display of any lab computer while the instructor and student share control. The student’s work can be interactively modified during a critique session, resulting in an engaging experience for the entire class.


Towards The Prediction Of Mutations In Genomic Sequences, Juan Carlos Martinez Nov 2013

Towards The Prediction Of Mutations In Genomic Sequences, Juan Carlos Martinez

FIU Electronic Theses and Dissertations

Bio-systems are inherently complex information processing systems. Furthermore, physiological complexities of biological systems limit the formation of a hypothesis in terms of behavior and the ability to test hypothesis. More importantly the identification and classification of mutation in patients are centric topics in today’s cancer research.

Next generation sequencing (NGS) technologies can provide genome-wide coverage at a single nucleotide resolution and at reasonable speed and cost. The unprecedented molecular characterization provided by NGS offers the potential for an individualized approach to treatment. These advances in cancer genomics have enabled scientists to interrogate cancer-specific genomic variants and compare them with ...


Development Of An Enhanced Hydro-Geochemical Model To Address Mercury-Speciation Fate And Transport In Aquatic Environments, Nantaporn Noosai Nov 2013

Development Of An Enhanced Hydro-Geochemical Model To Address Mercury-Speciation Fate And Transport In Aquatic Environments, Nantaporn Noosai

FIU Electronic Theses and Dissertations

An awareness of mercury (Hg) contamination in various aquatic environments around the world has increased over the past decade, mostly due to its ability to concentrate in the biota. Because the presence and distribution of Hg in aquatic systems depend on many factors (e.g., pe, pH, salinity, temperature, organic and inorganic ligands, sorbents, etc.), it is crucial to understand its fate and transport in the presence of complexing constituents and natural sorbents, under those different factors. An improved understanding of the subject will support the selection of monitoring, remediation, and restoration technologies.

The coupling of equilibrium chemical reactions with ...


Computer Simulation Study Of Slipper Lubrication In Hydraulic Machines, Jordyn B. Miller, Monika Ivantysynova Oct 2013

Computer Simulation Study Of Slipper Lubrication In Hydraulic Machines, Jordyn B. Miller, Monika Ivantysynova

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hydraulic pumps and motors are vital components used in many applications today. Specifically, the axial piston pump is important because it is reliable, relatively compact, and has a high horsepower-to-weight ratio. These features make this type of pump very advantageous in hydraulic systems. Maintaining proper lubrication between surfaces in an axial pump, such as the slipper and swashplate, is imperative in order to have smooth operation of the system and prevent metal-to-metal contact. The aim of this research is to find the optimal slipper design and fluid film thickness to simultaneously maintain a balanced pressure and decrease power loss in ...


Direct Simulation Monte Carlo Simulation Toolkit For Equilibrium (0d) And Planar Couette Flow (1d), Austin I. Saragih, Alina A. Alexeenko Oct 2013

Direct Simulation Monte Carlo Simulation Toolkit For Equilibrium (0d) And Planar Couette Flow (1d), Austin I. Saragih, Alina A. Alexeenko

The Summer Undergraduate Research Fellowship (SURF) Symposium

Visualized simulation tool of Direct Simulation Monte Carlo (DSMC) is essential in aeronautical engineering and gas dynamics, by presenting information that can educate engineers and scientists to preliminarily understand the molecular gas dynamics and direct simulation of gas flows. Two educational tools and models are described for rarified gas flows and simulated particle collisions. A 0-Dimensional DSMC in approach to translational equilibrium was developed to simulate the speed distribution over time and the comparison between the final distribution and the Maxwell-Boltzmann distribution. A 1-Dimensional DSMC for Planar Couette flow was also developed to calculate the number of strikes of the ...


Data Workflow In Large Scale Simulations Of Blood Flow In Aneurysms, Paolo Di Achille, Jay D. Humphrey Oct 2013

Data Workflow In Large Scale Simulations Of Blood Flow In Aneurysms, Paolo Di Achille, Jay D. Humphrey

Yale Day of Data

Aneurysms are responsibile for significant morbidity and mortality, and there is a need for an increased understanding of all the aspects of the natural history of these lesions. We are currently working to extend our analyses with the goal of creating models of aneurysmal progression that are able to predict rupture risk through the description of the evolving geometry, structure, properties, and loads.

Realization of patient specific models of the blood circulation necessitates a complex computationally and data intensive procedure that starts from the collection of medical images in a clinical setting and encompasses several stages of data processing on ...


Service Oriented Solution Modeling And Variation Propagation Analysis Based On Architectural Building Blocks, Liang-Jie Zhang, Jia Zhang Sep 2013

Service Oriented Solution Modeling And Variation Propagation Analysis Based On Architectural Building Blocks, Liang-Jie Zhang, Jia Zhang

Jia Zhang

In spite of the widely recognized benefits of applying Service Oriented Architecture (SOA) to design enterprise-scale software systems, its actual application practice is not always a success. One major reason is the lack of a systematic engineering process and tool supported by reusable architectural artifacts. Toward this ultimate goal, this paper proposes a new method of architectural building blocks (ABB)-based SOA solution design and it is applicable to any layered or tiered infrastructure. We present the modeling of solution-level architectural artifacts and their relationships, whose formalization enables event-based variation notification and propagation analysis. The goal is to provide architecture-level ...


Bionano Electronics: Magneto-Electric Nanoparticles For Drug Delivery, Brain Stimulation And Imaging Applications, Rakesh Guduru Sep 2013

Bionano Electronics: Magneto-Electric Nanoparticles For Drug Delivery, Brain Stimulation And Imaging Applications, Rakesh Guduru

FIU Electronic Theses and Dissertations

Nanoparticles are often considered as efficient drug delivery vehicles for precisely dispensing the therapeutic payloads specifically to the diseased sites in the patient’s body, thereby minimizing the toxic side effects of the payloads on the healthy tissue. However, the fundamental physics that underlies the nanoparticles’ intrinsic interaction with the surrounding cells is inadequately elucidated. The ability of the nanoparticles to precisely control the release of its payloads externally (on-demand) without depending on the physiological conditions of the target sites has the potential to enable patient- and disease-specific nanomedicine, also known as Personalized NanoMedicine (PNM). In this dissertation, magneto-electric nanoparticles ...


Binaural Spatialization For 3d Immersive Audio Communication In A Virtual World, Davide Andrea Mauro, Rufael Mekuria, Michele Sanna Sep 2013

Binaural Spatialization For 3d Immersive Audio Communication In A Virtual World, Davide Andrea Mauro, Rufael Mekuria, Michele Sanna

Weisberg Division of Computer Science Faculty Research

Realistic 3D audio can greatly enhance the sense of presence in

a virtual environment. We introduce a framework for capturing,

transmitting and rendering of 3D audio in presence of other

bandwidth savvy streams in a 3D Tele-immersion based virtual

environment. This framework presents an efficient implementation

for 3D Binaural Spatialization based on the positions of current

objects in the scene, including animated avatars and on the fly

reconstructed humans. We present a general overview of the

framework, how audio is integrated in the system and how it can

exploit the positions of the objects and room geometry to render

realistic ...


Adaptive Co-Scheduler For Highly Dynamic Resources, Kartik Vedalaveni Aug 2013

Adaptive Co-Scheduler For Highly Dynamic Resources, Kartik Vedalaveni

Theses, Dissertations, & Student Research in Computer Electronics & Engineering

There are many kinds of scientific applications that run on high throughput computational (HTC) grids. HTC may utilize clusters opportunistically, only running on a given cluster when it is otherwise idle. These widely dispersed HTC clusters are heterogeneous in terms of capability and availability, but can provide significant computing power in aggregate. The scientific algorithms run on them also vary greatly. Some scientific algorithms might use high rates of disk I/O and some might need large amounts of RAM. Most schedulers only consider cpu availability, but unchecked demand on these associated resources that aren’t managed by resource managers ...


Creating A Package In R, Brit Schneiders, Eric Archer Aug 2013

Creating A Package In R, Brit Schneiders, Eric Archer

STAR (STEM Teacher and Researcher) Presentations

In a time of increasingly efficient technology and data production, scientists are producing data faster than it can be analyzed. Therefore, user accessibility to data analysis is becoming more and more critical. In general, researchers have a set of raw data and want an efficient means to their final analysis. A package serves as that means by creating a set of functions and making them accessible to the user. Often, a user has a small piece of code to run (a single R script, for example), and that script requires the use of certain functions, which are contained in a ...


Network Dynamics Of Visual Naming, Christopher R. Conner Aug 2013

Network Dynamics Of Visual Naming, Christopher R. Conner

UT GSBS Dissertations and Theses (Open Access)

Recognition and naming of objects and actions are fundamental components of language. They involve several different systems working in coordination to accomplish a complex behavior. During visual naming, sensory and semantic processing are carried out by dedicated cortical substrates in the temporal and occipital lobes, while response selection and articulatory planning are handled by prefrontal cortex. Despite decades of research using lesion analysis, functional MRI and electro-encephalography, the precise dynamics involved remain unknown due to the inadequate spatio-temporal resolution of these methodologies. Of particular interest is the organization of semantic knowledge and the degree of serial and parallel organization of ...


Essentially Analytical Theory Closure For Space Filtered Thermal-Incompressible Navier-Stokes Partial Differential Equation System On Bounded Domains, Mikhail Alexandrovich Sekachev Aug 2013

Essentially Analytical Theory Closure For Space Filtered Thermal-Incompressible Navier-Stokes Partial Differential Equation System On Bounded Domains, Mikhail Alexandrovich Sekachev

Doctoral Dissertations

Numerical simulation of turbulent flows is identified as one of the grand challenges in high-performance computing. The straight forward approach of solving the Navier-Stokes (NS) equations is termed Direct Numerical Simulation (DNS). In DNS the majority of computational effort is spent on resolving the smallest scales of turbulence, which makes this approach impractical for most industrial applications even on present-day supercomputers. A more feasible approach termed Large Eddy Simulation (LES) has evolved over the last five decades to facilitate turbulent flow predictions for reasonable Reynolds (Re) numbers and domain sizes. LES theory uses the concept of convolution with a spatial ...


Quantifying Organic Solar Cell Morphology: A Computational Study Of Three-Dimensional Maps, Olga Wodo, John D. Roehling, Adam J. Moulé, Baskar Ganapathysubramanian Aug 2013

Quantifying Organic Solar Cell Morphology: A Computational Study Of Three-Dimensional Maps, Olga Wodo, John D. Roehling, Adam J. Moulé, Baskar Ganapathysubramanian

Mechanical Engineering Publications

Establishing how fabrication conditions quantitatively affect the morphology of organic blends opens the possibility of rationally designing higher efficiency materials; yet such a relationship remains elusive. One of the major challenges stems from incomplete three-dimensional representations of morphology, which is due to the difficulties of performing accurate morphological measurements. Recently, three-dimensional measurements of mixed organic layers using electron tomography with high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) provided maps of morphology with high resolution and detail. Using a simple, yet powerful, computational tool kit, these complex 3D datasets are converted into a set of physically meaningful morphology descriptors. These ...


Computational Investigation Of The Effects Of Casing Treatments On The Performance Of A Turbofan, Weiyang Lin Aug 2013

Computational Investigation Of The Effects Of Casing Treatments On The Performance Of A Turbofan, Weiyang Lin

Masters Theses and Doctoral Dissertations

A computational survey focused on modifications to the casing near the rotor blade tip is carried out for the purpose of enhancing the performance and increasing the stall margin of a model turbofan stage in transonic operating conditions. The study is divided into three phases. During the first phase two types of casing treatments, inward protruding rings and circumferential grooves, were tested with relatively coarse grids. In the second phase, a grid resolution study is carried out with the results from this phase influencing the choices for the third stage. In the third phase, a comprehensive study is performed to ...