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Experimental Validation Data For Cfd Of Steady And Transient Mixed Convection On A Vertical Flat Plate, Blake W. Lance

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Simulations are becoming increasingly popular in science and engineering. One type of simulation is Computation Fluid Dynamics (CFD) that is used when closed forms solutions are impractical. The field of Verification & Validation emerged from the need to assess simulation accuracy as they often contain approximations and calibrations.

Validation involves the comparison of experimental data with simulation outputs and is the focus of this work. Errors in simulation predictions may be assessed in this way. Validation requires highly-detailed data and description to accompany these data, and uncertainties are very important.

The purpose of this work is to provide highly complete …

Buckling Instability Of Crown Sealing, J. O. Marston, Mohammad M. Mansoor, Tadd T. Truscott, S. T. Thoroddsen

Mechanical and Aerospace Engineering Faculty Publications

Despite the scholarly fascination with water entry of spheres for well over a century,¹ we present a new observation, namely, the crown-buckling instability. This instability is characterized by striations appearing near the top of the crown walls just prior to the surface seal, as shown in Fig. 1(a). The crown wall collapses inward due to the pressure differential across the wall created by the moving air in the wake of the sphere and surface tension within the crown. Since the rate of collapse is faster than that at which fluid drains out from the neck region, fluid collects into …

High Regression Rate Hybrid Rocket Fuel Grains With Helical Port Structures, Stephen A. Whitmore, Sean D. Walker, Daniel P. Merkley, Mansour Sobbi

Mechanical and Aerospace Engineering Faculty Publications

Results froma development campaign, where modern additive manufacturing methods are used to fabricate hybrid rocket fuel grains with embedded helical ports, are presented. The fuel grains were constructed from acrlyonitrile butadiene styrene using commercially available three-dimensional printer feedstockmaterial.Gaseous oxygen is used as the oxidizer for this test campaign.When compared to cylindrical fuel ports, significant increases in fuel regression rates were observed, and these increases in regression rate diminished with time as the helical fuel port burns to become progressivelymore cylindrical. Comparisons to the helical pipe flow skin friction correlation developed by Mishra and Gupta indicate that increased skin friction only …

Matryoshka Cavity, Randy Craig Hurd, T. Fanning, Zhao Pan, C. Maybey, Kyle G. Bodily, Kip Schafer Hacking, Nathan B. Spiers, Tadd T. Truscott

Mechanical and Aerospace Engineering Faculty Publications

When a water droplet impacts a free surface with sufficient velocity, the momentum transfer results in the formation of a hemispherical cavity expanding radially from the point of impact.¹ This cavity continues to expand until the kinetic energy is completely converted to potential energy (Fig. 1(a)).² Pumphrey and Elmore equated the potential energy of this subsurface cavity with the kinetic energy of the impacting droplet, concluding that the magnitude of the cavity radius is proportional to impact velocity and droplet diameter.³

Experimental Validation Data For Cfd Of Mixed Convection On A Vertical Flat Plate, Blake W. Lance, Jeff R. Harris, Barton L. Smith

Mechanical and Aerospace Engineering Faculty Publications

Model validation for Computational Fluid Dynamics(CFD), where experimental data and model outputs are com-pared, is a key tool for assessing model uncertainty. In this work, mixed convection is studied experimentally for the purpose of providing validation data for CFD models with a high level of completeness. Experiments are performed in a facility built specifically for validation with a vertical, flat,heated wall. Data were acquired for both buoyancy-aided and buoyancy-opposed flows. Measured boundary conditions include as-built geometry, inflow mean and fluctuating velocity profiles, and inflow and wall temperatures. Additionally, room air temperature, pressure, and relative humidity are measured to provide fluid …

The Study Of Frequency-Scan Photothermal Reflectance Technique For Thermal Diffusivity Measurement, Zilong Hua, Heng Ban, David H. Hurley

Mechanical and Aerospace Engineering Faculty Publications

A frequency scan photothermal reflectance technique to measure thermal diffusivity of bulk samples is studied in this manuscript. Similar to general photothermal reflectance methods, an intensity-modulated heating laser and a constant intensity probe laser are used to determine the surface temperature response under sinusoidal heating. The approach involves fixing the distance between the heating and probe laser spots, recording the phase lag of reflected probe laser intensity with respect to the heating laser frequency modulation, and extracting thermal diffusivity using the phase lag–(frequency)^1/2 relation. The experimental validation is performed on three samples (SiO₂, CaF₂, and …

Design And Testing Of A Nanosatellite Simulator Reaction Wheel Attitude Control System, Fredric William Long

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Attitude control of a satellite is required for the pointing of communications antennas and other instruments. For this reason, a control algorithm capable of precision pointing is important. Because the process of sending a satellite into space is time consuming and costly, ground-based methods of testing are paramount. A simulator is a low-cost, groundbased system made to mimic the conditions of a weightless satellite in space. The simulator used in this project controls attitude through applying torque to reaction wheels. The objective of this project is to derive and test a control algorithm for the attitude control of a satellite …

Control Of The Diffracted Response Of A Metallic Wire Array With Double Period: Experimental Demonstration, Nicholas A. Roberts, D. C. Skigin, J. D. Fowlkes, L. B. Scaffardi, D. C. Schinca, M. Lester

Mechanical and Aerospace Engineering Faculty Publications

In recent papers, it has been theoretically shown that by using dual-period wire gratings, it is possible to control the relative efficiencies of the diffracted orders, regardless of the wires’ material, incident polarization and wavelength. In this Letter, we experimentally demonstrate, for the first time, that by appropriately choosing the geometrical parameters of a nanometric periodic structure, it is possible to control the optical response in the visible range. We show examples of nanostructures designed to cancel out or to intensify a particular diffraction order. Such nanostructures allow a broad control over the directionality and the intensity of the diffracted …

Retrofitting Two Solar Hot Water Systems For Year Round Operation, Zachary A. Cook

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Solar energy in a variety of applications is again becoming more widely used. Solar collectors have been installed during the construction of two Utah State University buildings: Wetlands Discovery located in Kaysville, Utah and Swaner Nature Preserve located in Park City, Utah. While these systems are capable of capturing a significant amount of solar energy, problems have been encountered when the demand is less than the system’s capacity. This project report documents the problems encountered while operating the two solar water heating systems and how the systems were modified to be operational year round under typical operating conditions. The peak …

Spacecraft Guidance Techniques For Maximizing Mission Success, Shane B. Robinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Traditional spacecraft guidance techniques have the objective of deterministically minimizing fuel consumption. These traditional approaches to guidance are developed independently of the navigation system, and without regard to stochastic effects. This work presents and demonstrates a new approach to guidance design. This new approach seeks to maximize the probability of mission success by minimizing the variance of trajectory dispersions subject to a fuel consumption constraint. The fuel consumption constraint is imposed by formulating the dynamics in terms of a steering command, and placing a constraint on the final time. Stochastic quadratic synthesis is then used to solve for the nominal …

Personal Vacuum Assisted Climber, Jacob Monroe Whittle

Undergraduate Honors Capstone Projects

The Personal Vacuum Assisted Climber (PVAC) system built in 2012 by the Ascending Aggies at Utah State University which was designed using vacuum motors to provide suction to pads to allow the user to climb various surfaces, needs to be further developed before being fully marketable. The current system does not have a user-friendly interface and is very loud (approx. 90 dB). These issues were addressed to answer the following question: how can the current PV AC system be optimized to decrease noise and produce a user friendly interface while maintaining current run time? To obtain the sound reduction desired …

Pvc Pipe Longevity Report: Affordability And The 100+ Year Benchmark Standard, Steven Folkman

Mechanical and Aerospace Engineering Faculty Publications

In the United States and Canada, underground water infrastructure was installed during three main time periods because of population growth in the 1800s, 1900–1945, and post 1945. Pipes made of iron constructed in each of these three eras will all start to fail at nearly the same time over the next couple of decades due to the corrosion of the iron pipes. Additionally, the life span of the materials used since the 1960's has changed. Grey cast iron pipes are no longer manufactured and the new ductile iron material has been made thinner to reduce costs, but as a result, …

Global Evaluation Of Biofuel Potential From Microalgae, Jeffrey W. Moody

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of the proposed work is to determine the productivity potential of microalgae around the world based on the current large uncertainty of the productivity
potential found in literature. To achieve this objective, a validated thermal and biological growth model was utilized coupled with weather data files from weather stations around the world. This enabled a realistic assessment of the productivity potential based on actual climatic variables. Sensitivity of microalgae lipid productivity to biomass production, temperature, and variability was performed illustrating the importance of biological and temporal resolution. Results from modeling work were leveraged for a scalability assessment based …

The Design And Testing Of A Three-Degree-Of-Freedom Small Satellite Simulator Using A Linear Controller With Feedback Linearization And Trajectory Generation, Marina A. Samuels

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A small satellite simulator with attitude determination and control was designed and implemented in hardware. The simulator consists of inertial sensors for attitude determination and a pyramidal four-wheel momentum exchange system as the control actuators. A linearized PV controller with trajectory generation and feedback linearization was implemented, with the focus on controlling yaw. The simulator was tested on a spherical air bearing platform to allow three-degree-of-freedom operation. The simulator software was developed to read measurements from the sensors, apply the control algorithm, and send commands to the actuators. A data processing routine was developed. Electromechanical testing for the system as …

A Computational Fluid Dynamics Validation Experiment For Forced And Mixed Convection On A Vertical Heated Plate, Jeff Robert Harris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A computational fluid dynamics (CFD) validation experiment is conducted for flow over a heated vertical plate. The design of the experiment to meet CFD validation standards is described. Many experiments and simulations have been completed in past studies, but none measure or present the necessary boundary conditions to define the simulation. Experimental measurements of heated flow are presented, along with corresponding boundary conditions sufficient to define the simulation's boundary conditions. Some simulation results are described, but a complete validation study is not included. The simulations are conducted by the experimentalist to ensure all necessary boundary conditions are being measured. This …

System Identification Of A Small Low-Cost Unmanned Aerial Vehicle Using Flight Data From Low-Cost Sensors, Nathan V. Hoffer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Remote sensing has usually been done with satellites and manned aircraft. While they can be useful, satellites and manned aircraft have issues in how quickly you can get data, process it, and go back to get more data. Small low-cost unmanned aerial vehicles (UAVs) overcome these issues. To collect precise data a precise model of the UAV is needed to develop the autopilot, make sure the aircraft flies well, and does not break. One method of making a model is system identification (system ID). In this thesis system ID of a small low-cost fixed-wing T-tail UAV is done. The equations …

Uncertainty Analysis Of Mechanical Properties From Miniature Tensile Testing Of High Strength Steels, Deepthi Rao Malpally

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This Miniature mechanical testing study is concerned with the use of miniature specimens to identify the mechanical properties of stainless steel Type 304, sensitized Type 304 and SA516 Grade 70 carbon steel as a viable replacement for the standard sized mechanical testing. The study aims at obtaining suitable specimen geometry and tensile testing procedure for miniature mechanical testing whose mechanical properties are comparable to that of conventional specimens of ASTM A370-10 of the same steel. All specimens are at and the gauge length cross section will be varied to obtain suitable geometry. The miniature tensile testing results are further validated …

The Analysis And Manufacturing Of The Personal Vacuum Assisted Climber Ii, Rhet B. Astle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Personal Vacuum Assisted Climber or PVAC for short (as shown in Fig 2) is a new means for climbing walls. Unlike ordinary climbing methods used today, the PVAC scales walls via suction. This suction is produced by three spinning impellers within each vacuum motor, which removes air from a sealed area. A climber pulls down on a vacuum pressure release mechanism to release the vacuum. Foot stirrups are used by the climber to climb to the next higher step. This allows the strength of the climber's legs to lift his/her body reducing arm fatigue, allowing rapid ascension of any …

Experimental Studies Of Delta Wing Parameters In Open Channel Raceway Determined Via Validated Computational Fluid Dynamics, Cole David Blakely

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A promising feedstock for biofuels is microalgae. The most economical means of cultivating microalgae is via open raceway ponds. However, a large gap in economic feasibility exists between algae-based biofuels and traditional petroleum fuels. Recent research at Utah State University has focused on increasing biomass growth by implementing Delta Wings (DWs). DWs are placed facing the incoming flow, with a 40 degree angle of attack to create large vortices which travel downstream. The trailing vortices increase vertical mixing, which in turn increases algal growth.

Past researchers at USU quantified vertical mixing with new metrics, optimized various raceway operating conditions, and …

Bridging The Nano- And Macro-Worlds: Thermal Property Measurement Using Thermal Microscopy And Photothermal Radiometry – Application To Particle-Irradiation Damage Profile In Zirconium Carbide, Colby Bruce Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multiscaled experimental investigations of heat transfer from nanoscales to macroscales are requisite to progress in energy technologies. In nuclear applications, material properties can undergo significant alteration due to destructive interaction with irradiating particles at microstructural levels that affect bulk properties. This study expands the current knowledge base regarding thermal transport in ion-irradiated materials through the use of a multiscaled experimental approach using four complementary thermal wave methods. For the first time, the in-depth thermal conductivity profile of an ion-irradiated sample is measured directly.

Numerical Examination Of Flux Correction For Solving The Navier-Stokes Equations On Unstructured Meshes, Dalon G. Work

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work examines the feasibility of a novel high-order numerical method, which has been termed Flux Correction. This is accomplished by comparing it against another high-order method called Flux Reconstruction. These numerical methods are used to solve the Navier-Stokes equations, which govern the motion of fluid flow. High-order numerical methods, or those that demonstrate a third-order and higher solution error convergence rate, are rarely used on unstructured meshes when solving fluid problems. Flux Correction intends to make high-order accuracy available to the larger world of Computational Fluid Dynamics in a simple and effective manner. The advantages and disadvantages of the …

The Influence Of Mesa Activities On Underrepresented Students Nsf Dr K-12 Proposal 1020019, C. Hailey, Chandra Austin Stallworth, Cameron Denson, Daniel L. Householder

Mechanical and Aerospace Engineering Faculty Publications

Mathematics, Engineering, Science Achievement (MESA) outreach programs are partnerships between K-12 schools and higher education in nine states. MESA efforts introduce integrated experiences in science, mathematics and engineering to K-12 students from groups that are traditionally underrepresented in the STEM disciplines. This exploratory study examined the influence of selected MESA activities on students' self-efficacy, their perceptions of engineering, and their interest in engineering and other STEM fields. Field trips, guest lecturers, design competitions, hands-on activities and student career and academic advisement were of specific interest in this survey. The project also investigated the relationship between student engagement in MESA and …

Design And Construction Of An Omni-Directional Soccer Ball Thrower, Andrew James Marquette

Undergraduate Honors Capstone Projects

Introduction

We are ODST the Omni-Directional Soccer Ball Thrower team which designed the soccer ball launching machine. Working in direct correlation with the project sponsor John Meade from Athlonic Sports this is the report outlining the soccer ball thrower. John from Athlonic Sports came up with the overall project and initial project vision. There are soccer ball launching machines on the market but lacking mobility, not amiable and are heavy. The design needed to be mobile, amiable, lightweight, and have a soccer ball capacity incorporated into the machine. This will allow coaches to repeatability place the soccer ball in certain …

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 …

Lifting-Line Predictions For Induced Drag And Lift In Ground Effect, W. F. Phillips, Doug F. Hunsaker

Mechanical and Aerospace Engineering Faculty Publications

Closed-form relations are presented for estimating ratios of the induced-drag and lift coefficients acting on a wing in ground effect to those acting on the same wing outside the influence of ground effect. The closed-form relations for these ground-effect influence ratios were developed by correlating results obtained from numerical solutions to Prandtl’s lifting-line theory. Results show that these influence ratios are not unique functions of the ratio of wing height to wingspan, as is sometimes suggested in the literature. These ground-effect influence ratios also depend on the wing planform, aspect ratio, and lift coefficient.

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 …

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 …

Lifting-Line Predictions For Induced Drag And Lift In Ground Effect, W. F. Phillips, Doug F. Hunsaker

Mechanical and Aerospace Engineering Faculty Publications

Closed-form relations are presented for estimating ratios of the induced-drag and lift coefficients acting on a wing in ground effect to those acting on the same wing outside the influence of ground effect. The closed-form relations for these ground-effect influence ratios were developed by correlating results obtained from numerical solutions to Prandtl's lifting-line theory. Results show that these influence ratios are not unique functions of the ratio of wing height to wingspan, as is sometimes suggested in the literature. These ground-effect influence ratios also depend on the wing planform, aspect ratio, and lift coefficient.

Momentum Theory With Slipstream Rotation Applied To Wind Turbines, Doug F. Hunsaker, W. F. Phillips

Mechanical and Aerospace Engineering Faculty Publications

A momentum theory which includes the effects of slipstream rotation for wind turbines is presented. The theory accounts for the axial and radial pressure gradients within the slipstream as well as the wake expansion caused by wake rotation. Because of the limiting approximations of previous methods, the effects of slipstream rotation have not been accurately realized. The method included here, which does not suffer from the unrealistic approximations of previous methods, predicts that the effects of slipstream rotation are manifest entirely through an increase in the turbine thrust coefficient. The method predicts, as previous methods do, that the Lanchester-Betz-Joukowski limit …

Decomposed Lifting-Line Predictions And Optimization For Propulsive Efficiency Of Flapping Wings, W. F. Phillips, R. A. Miller, Doug F. Hunsaker

Mechanical and Aerospace Engineering Faculty Publications

A decomposed Fourier series solution to Prandtl's classical lifting-line theory is used to predict the lift, induced-thrust, and power coefficients developed by a flapping wing. A significant advantage of this quasi-steady analytical solution over commonly used numerical methods is the utility provided for optimizing wing flapping cycles. The analytical solution involves five time-dependent functions that could all be optimized to maximize thrust, propulsive efficiency, and/or other performance measures. Results show that by optimizing only two of these five functions, propulsive efficiencies exceeding 97% can be obtained. Results are presented for untwisted rectangular wings in pure plunging, rectangular wings with linear …