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A Novel Approach To Evaluating Compact Finite Differences And Similar Tridiagonal Schemes On Gpu-Accelerated Clusters, Ashwin Trikuta Srinath Dec 2015

A Novel Approach To Evaluating Compact Finite Differences And Similar Tridiagonal Schemes On Gpu-Accelerated Clusters, Ashwin Trikuta Srinath

All Theses

Compact finite difference schemes are widely used in the direct numerical simulation of fluid flows for their ability to better resolve the small scales of turbulence. However, they can be expensive to evaluate and difficult to parallelize. In this work, we present an approach for the computation of compact finite differences and similar tridiagonal schemes on graphics processing units (GPUs). We present a variant of the cyclic reduction algorithm for solving the tridiagonal linear systems that arise in such numerical schemes. We study the impact of the matrix structure on the cyclic reduction algorithm and show that precomputing forward reduction …


An Analysis Of Partial-Depth, Floating, Impermeable Guidance Structures For Downstream Fish Passage At Hydroelectric Facilities, Kevin Mulligan Nov 2015

An Analysis Of Partial-Depth, Floating, Impermeable Guidance Structures For Downstream Fish Passage At Hydroelectric Facilities, Kevin Mulligan

Doctoral Dissertations

Partial-depth, impermeable guidance structures (or guide walls) are used to enhance downstream passage effectiveness at a hydroelectric facility by actively guiding fish to a safe passage route (i.e. the bypass). Guide walls have been installed in a variety of ways and, like many fish passage devices, have resulted in variable efficiency rates. Currently, the most common type of installment is a steel panel guide wall attached to a floating boom. While less utilized than other guidance structure options (e.g. louvers and bar racks), guide walls have been gaining popularity, particularly within the Northwest United States. The aim of this dissertation …


Using Star-Ccm+ To Evaluate Multi-User Collaboration In Cfd, Kasey Johnson Webster Oct 2015

Using Star-Ccm+ To Evaluate Multi-User Collaboration In Cfd, Kasey Johnson Webster

Theses and Dissertations

The client-server architecture of STAR-CCM+ allows multiple users to collaborate on a simulation set-up. The effectiveness of collaboration with this architecture is tested and evaluated on five models. The testing of these models is a start to finish set-up of an entire simulation excluding computational time for generating mesh and solving the solution. The different models have distinct differences which test every operation that would be used in a general CFD simulation. These tests focus on reducing the time spent preparing the geometry to be meshed, including setting up for a conformal mesh between multiple regions in conjugate heat transfer …


Model Of A Tubular Perfusion Bioreactor Using Computational Fluid Dynamics., Matthew James Robeson 1991- Jul 2015

Model Of A Tubular Perfusion Bioreactor Using Computational Fluid Dynamics., Matthew James Robeson 1991-

Electronic Theses and Dissertations

Through recent years, many novel bioreactor designs for tissue engineering have emerged. The Tubular Perfusion System (TPS) is one such bioreactor for bone and cartilage tissue engineering. The TPS is a perfusion type bioreactor, in which media flows through a bed of scaffold beads. The advantage of this system over similar designs is that it requires no special fabrication techniques and operates at low pressure. Experimental trials have shown increased osteoblastic differentiation and mineralization of bone tissue grown using the TPS versus static culture. The effectiveness of the TPS in promoting osteoblastic differentiation is believed to be due to enhanced …


Three Dimensional Simulations Of Tornado Sheltering Effect Of Man-Made Structures, Piotr Gorecki May 2015

Three Dimensional Simulations Of Tornado Sheltering Effect Of Man-Made Structures, Piotr Gorecki

Graduate Theses and Dissertations

A three dimensional computational fluid dynamics (CFD) model was utilized to investigate tornado-like vortex interactions with wide man-made structures. The tornado-like wind profile was approximated using Rankine vortex model. By utilizing the CFD model, it was explained why tornadoes exhibit less damage on leeward side of large structures. During the preliminary stage of this study, a perpendicular vortex-prism interaction was analyzed. The prism height and the length were equal to the vortex core radius. The prism was also 12 times wider than the vortex core radius. During the vortex-prism interaction, the near-ground portion of the vortex was blocked by the …


Disinfection And Advanced Oxidation Of Highly Absorbing Fluids By Uv/Vuv Light: Process Modeling And Validation, Ferdinando Crapulli Apr 2015

Disinfection And Advanced Oxidation Of Highly Absorbing Fluids By Uv/Vuv Light: Process Modeling And Validation, Ferdinando Crapulli

Electronic Thesis and Dissertation Repository

One of the limitations in treating highly absorbing fluids with ultraviolet photoreactors is the short light penetration into the fluid leading to the following issues: (a) if not engineered properly, ultraviolet photoreactors dealing with highly absorbing fluids are likely to be energy-inefficient due to a non-ideal use of emitted photons and non-uniform dose distribution (b) the quantification of photo-chemical rate constants could be a challenging task due to the severe mixing-limited conditions of the experimental apparatus used during the investigation. As a result, new lab-scale apparatus (alternative to the conventional collimated beam system) and modeling approaches are needed in order …


Meshless Direct Numerical Simulation Of Turbulent Incompressible Flows, Andres Vidal Urbina Jan 2015

Meshless Direct Numerical Simulation Of Turbulent Incompressible Flows, Andres Vidal Urbina

Electronic Theses and Dissertations

A meshless direct pressure-velocity coupling procedure is presented to perform Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES) of turbulent incompressible flows in regular and irregular geometries. The proposed method is a combination of several efficient techniques found in different Computational Fluid Dynamic (CFD) procedures and it is a major improvement of the algorithm published in 2007 by this author. This new procedure has very low numerical diffusion and some preliminary calculations with 2D steady state flows show that viscous effects become negligible faster that ever predicted numerically. The fundamental idea of this proposal lays on several important inconsistencies …


Analytical And Numerical Validation Of Nozzle Spray Measurement Data Obtained From A Newly Developed Production System, Iddrisu Seidu Jan 2015

Analytical And Numerical Validation Of Nozzle Spray Measurement Data Obtained From A Newly Developed Production System, Iddrisu Seidu

ETD Archive

A newly developed production test stand for measuring the spray angle of a pressure swirl atomizer was constructed and used to measure a product line of these pressure swirl atomizers -- the macrospray atomizer. This new test stand, utilizing constant temperature hot wire anemometers, captures the spray angle data based on the voltage drop the hot wire probes see as they traverse the spray cone of the atomizer and as fluid droplets impinge upon the wire. Datasets acquired from the experiments are compared and correlated with computational fluid dynamics (CFD) simulation data. In addition, angles obtained from another type of …


Air Flow And Rain Water Penetration Analysis On Generator Enclosures Using Cfd Simulations, Sasanka Andawatta Kankanamge Jan 2015

Air Flow And Rain Water Penetration Analysis On Generator Enclosures Using Cfd Simulations, Sasanka Andawatta Kankanamge

All Graduate Theses, Dissertations, and Other Capstone Projects

Rain water penetration testing on power generator units requires a number of complicated procedures, requiring many resources. As such, a Computational Fluid Dynamics (CFD) tool, "FloEFD for Creo" is used to study the water penetration behavior on a OM924 diesel power generator enclosure in a computational environment. First, the three governing equations in fluid dynamics are derived and explained using simple methods. Next, behavior of rain water droplets upon impact is briefly discussed. Air velocity, volumetric flow rate and static pressure drop were measured physically in the OM924 generator enclosure. Then, a CFD model for the OM924 enclosure was developed …


Investigating Wave Forces On Coastal Bridge Decks, Guoji Xu Jan 2015

Investigating Wave Forces On Coastal Bridge Decks, Guoji Xu

LSU Doctoral Dissertations

Tsunamis and hurricane induced waves are responsible for many coastal bridge failures, especially in the last decade. In the current study, three countermeasures (reducing the entrapped air, elevating the structures and rigidifying the structures) are considered, two wave types (solitary wave theory and Stokes wave theory) are chosen, and two bridge types (single bridge deck and twin bridge decks) are taken into account. Parametric studies are conducted based on Computational Fluid Dynamics (CFD) software ANSYS Fluent. This dissertation comprises two broad themes according to the wave types adopted. The first one is to make a great effort to investigate solitary …


Developing Co-Current And Counter-Current Spray Drying Computational Fluid Dynamics (Cfd) Simulation Studies To Predict The Quality Of Microencapsulated Fish Oil With Egg White Hydrolysates Powders, Kevin Estuardo Mis Solval Jan 2015

Developing Co-Current And Counter-Current Spray Drying Computational Fluid Dynamics (Cfd) Simulation Studies To Predict The Quality Of Microencapsulated Fish Oil With Egg White Hydrolysates Powders, Kevin Estuardo Mis Solval

LSU Doctoral Dissertations

Eggs are an excellent source of high quality protein containing all essential amino acids (EAA) including leucine. Food-grade protein hydrolysates can enhance the growth of lactic acid bacteria (LAB). Thermal degradation of bioactives normally occurs during microencapsulation by spray drying. Spray drying modeling using computational tools is essential to engineer new food powders and to minimize and thermal degradation of bioactives. The first chapter of this work discusses the optimization of an enzymatic process in terms of reaction temperature, pH, enzyme:substrate ratio, and reaction time using a response surface methodology (RSM) to produce food-grade protein hydrolysates from egg whites (EWH). …