Engineering Commons^™

Development Of A Coupled Fluid And Colloidall Particle Transport Model, Scott Ripplinger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A colloidal system usually refers to when very small particles are suspended within a solution. The study of these systems encompasses a variety of cases including bacteria in ground water, blood cells and platelets in blood plasma, and river silt transport. Taking a look at these kinds of systems using computer simulation can provide a great deal of insight into how they work. Most approaches to date do not look at the details of the system, however, and are specific to given system. In this study a program called OpenFOAM is used as a basis to build a computer simulation …

Linear Covariance Analysis For Gimbaled Pointing Systems, Randall S. Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Linear covariance analysis has been utilized in a wide variety of applications. Historically, the theory has made significant contributions to navigation system design and analysis. More recently, the theory has been extended to capture the combined effect of navigation errors and closed-loop control on the performance of the system. These advancements have made possible rapid analysis and comprehensive trade studies of complicated systems ranging from autonomous rendezvous to vehicle ascent trajectory analysis. Comprehensive trade studies are also needed in the area of gimbaled pointing systems where the information needs are different from previous applications. It is therefore the objective of …

Nutrient And Carbon-Dioxide Requirements For Large-Scale Microalgae Biofuel Production, Benjamin K. Shurtz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ever-increasing fuel prices and a limited supply of oil worldwide are threatening our economy and way of life in both the near and distant future. In order to reduce oil
dependence, the US Department of Energy (DOE) has established a goal that by the year 2030, 30% of the US transportation fuel will be renewable. The goal equates to
approximately 60 billion gallons per year of renewable fuel.

In an effort to reach the DOE renewable fuel goal, numerous types of plants are being studied, whose oil can be harvested and refined to serve as replacement fuel.
Among the various …

Analysis Of Star Identification Algorithms Due To Uncompensated Spatial Distortion, Steven Paul Brätt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the evolution of spacecraft systems, we see the growing need for smaller, more affordable, and robust spacecrafts that can be jettisoned with ease and sent to sites to perform a myriad of operations that a larger craft would prohibit, or that can be quickly manipulated from performing one task into another. The developing requirements have led to the creation of Nano-Satellites, or CubeSats. The question then remains, how to navigate the expanse of space with such a minute spacecraft? A solution to this is using the stars themselves as a means of navigation. This can be accomplished by measuring …

Verification And Validation Of The Spalart-Allmaras Turbulence Model For Strand Grids, Oisin Tong

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The strand-Cartesian grid approach is a unique method of generating and computing fluid dynamic simulations. The strand-Cartesian approach provides highly desirable qualities of fully-automatic grid generation and high-order accuracy. This thesis focuses on the implementation of the Spalart-Allmaras turbulence model to the strand-Cartesian grid framework. Verification and validation is required to ensure correct implementation of the turbulence model.

Mathematical code verification is used to ensure correct implementation of new algorithms within the code framework. The Spalart-Allmaras model is verified with the Method of Manufactured Solutions (MMS). MMS shows second-order convergence, which implies that the new algorithms are correctly implemented.

Validation …

The Dynamic Analysis Of A Composite Overwrapped Gun Barrel With Constrained Viscoelastic Damping Layers Using The Modal Strain Energy Method, Braydon Day Hall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

By using composite materials and rubber overwrapped onto a steel liner, a new design for a gun barrel is investigated. Multiple configurations are analyzed and compared using the Finite Element Method and analytical solutions. By alternating layers of composite material and rubber over the steel liner, different reactions in the barrel are obtained when subjected to identical internal pressures from a projectile being fired. The ideal reaction desired from creating this new gun barrel is to dissipate energy more effectively than gun barrels made entirely of steel or overwrapped with just a composite material. The analyses show that multiple thin …

Thermo-Piezo-Electro-Mechanical Simulation Of Algan (Aluminum Gallium Nitride) / Gan (Gallium Nitride) High Electron Mobility Transistor, Lorin E. Stevens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to the current public demand of faster, more powerful, and more reliable electronic devices, research is prolific these days in the area of high electron mobility transistor (HEMT) devices. This is because of their usefulness in RF (radio frequency) and microwave power amplifier applications including microwave vacuum tubes, cellular and personal communications services, and widespread broadband access. Although electrical transistor research has been ongoing since its inception in 1947, the transistor itself continues to evolve and improve much in part because of the many driven researchers and scientists throughout the world who are pushing the limits of what modern …

Experimental Studies Of Vertical Mixing Patterns In Open Channel Flow Generated By Two Delta Wings Side-By-Side, Garrett Vaughan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Algae-derived biofuels is a hot topic of research interest when it comes to renewable energy applications. Algae can be grown in open systems that are low-cost, easy to maintain, and open to the environment. However, algae does not grow very dense in these systems. Mixing is an important factor in growing algae. If mixing were to be improved in open systems, the algae may be able to grow more dense. Certain studies show that placing a mechanical device such as an airfoil or airplane wing in the water will be able to increase the capability of mixing in the open …

Computational Fluid Dynamics Validation Of Buoyant Turbulent Flow Heat Transfer, Jared M. Iverson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Computational fluid dynamics (CFD) is commonly used to visualize and understand complicated fluid flow and heat transfer in many industries. It is imperative to validate the CFD computer models in order to avoid costly design choices where experimentation cannot be used to ratify the predictions of computer models. Assessments of CFD computer models in the literature conclude that significant errors occur in computer model predictions of fluid flow influenced by buoyancy forces.

The Experimental Fluid Dynamics Laboratory at Utah State University constructed a wind tunnel with which to perform experiments on buoyancy induced fluid flow. The experiments measured the heat …

Variational Asymptotic Method For Unit Cell Homogenization Of Thermomechanical Behavior Of Composite Materials, Chong Teng

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To seek better material behaviors, the research of material properties has been massively carried out in both industrial and academic fields throughout the twentieth century. Composite materials are known for their abilities of combining constituent materials in or- der to fulfill the desirable overall material performance. One of the advantages of composite materials is the adjustment between stiffness and lightness of materials in order to meet the needs of various engineering designs. Even though the finite element analysis is mature, composites are heterogeneous in nature and can present difficulties at the structural level with the acceptable computational time. A way …

Hybrid Photothermal Technique For Microscale Thermal Conductivity Measurement, Zilong Hua

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In nuclear reactors, the thermal energy generated from the nuclear reactions needs to be transferred all the way through the core of the fuels to the surrounding steam to be utilized. Therefore, thermal conductivity is considered an important thermophysical property of the fuel which needs to be measured. The nuclear fuel microstructure is known to be damaged by neutronirradiation, which can result in sharp, local changes of thermal conductivity. However, most existing thermal conductivity measurement techniques of nuclear fuel are not able to make high spatial-resolution measurements. The objective of this study was to develop a non-contact thermal conductivity measurement …