Mechanical Engineering Commons^™

Structure Functions, Scaling Exponents And Intermittency In The Wake Of A Wind Turbine Array, Naseem Ali, Aleksandr Sergeyevich Aseyev, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Hot-wire measurements obtained in a 3 × 3 wind turbine array boundary layer are utilized to analyze high order structure functions, intermittency effects as well as the probability density functions of velocity increments at different scales within the energy cascade. The intermittency exponent is found to be greater in the far-wake region in comparison with the near-wake. At hub height, the intermittency exponent is found to be null. Extended self-similarity scaling exponents of the second, fourth, and fifth order structure functions remain relatively constant as a function of height in the far-wake; whereas in the near-wake, these are highly affected …

Sound Attenuation In Amorphous Silica At Frequencies Near The Boson Peak, Zhi Liang, Pawel Keblinski

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We Use Molecular Dynamics Phonon Wave Packet (WP) Simulations to Study Acoustic Propagation and Attenuation in Amorphous Silica (A-SiO₂) at Frequencies Near the Boson Peak (BP) Position and Compare Them with the Results of Equilibrium Molecular Dynamics (EMD) Simulations. the Sound Attenuation Coefficients Obtained from WP Simulations Are Generally Consistent with Those from EMD Predictions and Have Reasonable Agreement with the Existing Experimental Data. Near the BP Position, We Found the Frequency-Dependent Sound Attenuation Coefficients for Longitudinal and Transverse Modes Both Follow the Rayleigh-Scattering Fourth Power Law. above the BP Frequency, However, the Propagating Phonon is Essentially Attenuated …

The Bambow: A Bamboo-Cored Carbon-Fiber Composite Bow, Ezekiel G. Merriam

Student Works

Archery is a sport that has benefited from thousands of years of development. Starting with primitive stick-bows, ancient people found they could propel projectiles larger distances and with more effectiveness than by hand or with other mechanical aids. Over the centuries different cultures adopted and advanced different aspects of the technology, including materials, geometry, and manufacturing methods. In the Mechanical Engineering Department at BYU, Nephi's Steel Bow Competition is held annually to challenge engineering students to test their knowledge of mechanics and materials. As a past participant in this competition, I felt building an advanced composite bow would be an …

Phased Retrofits In Existing Homes In Florida Phase I: Shallow And Deep Retrofits (February 2016), Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The U.S. Department of Energy's Building America research team Building America Partnership for Improved Residential Construction is collaborating with Florida Power & Light (FPL) to conduct a phased residential energy-efficiency retrofit program. This research seeks to establish impacts on annual energy and peak energy reductions from the technologies applied at two levels of retrofit--shallow and deep--with savings levels that approach the Building America program goal of reducing whole-house energy use by 40%.

Implementation Of Space-Time Finite Element Formulation In Elastodynamics, Sidharth Ramesh

Graduate Theses - Mechanical Engineering

Elastodynamics is an academic field that is involved in solving problems related to the field of wave propagation in continuous solid medium. Finite element methods have long been an accepted way of solving elastodynamics problems in the spatial dimension. Considerable thought has been given to ways of implementing finite element discretization in the temporal dimension as well. A particular method of finite element solving called space-time finite element formulation is explored in this thesis, which is a relatively recent technique for discretization in spatial and temporal dimensions. The present thesis explores the implementation of the Space-Time finite element formulation in …

Design Live Load Factor Calibration For Michigan Highway Bridges, Christopher D. Eamon, Valid Kamjoo, Kazuhiko Shinki

Civil and Environmental Engineering Faculty Research Publications

In this study, a reliability-based calibration of live load factors for bridge design specific to the State of Michigan was conducted. Two years of high frequency WIM data from 20 representative state-wide sites were analyzed, and load effects were generated for bridge spans from 6 to 122 m (20 to 400 ft), considering simple and continuous moments and shears, as well as single lane and two lane effects. Seventy-five year statistics for maximum live load were then estimated with probabilistic projection. Bridge girders considered for the calibration included composite steel, prestressed concrete, side-by-side and spread box beams, as well as …

Analysis And Simulation Of Small Scale Microwave Interferometer Experiments On Non-Ideal Explosives, David E. Kittell

Open Access Dissertations

Small scale experiments for non-ideal and homemade explosives (HMEs) were investigated, analyzed, and subsequently modeled in an attempt to develop more predictive capabilities for the threat assessment of improvised explosive devices (IEDs), as well as to provide new analysis capabilities for other investigators in the field. Non-ideal explosives and HMEs are challenging to characterize because of the nearly limitless parameter space (e.g. sample composition, density, particle morphology, etc.) which gives rise to a broad range of explosive sensitivity and performance. Large scale tests, such as rate stick and gap tests, are not feasible for characterizing every HME of interest due …

Wind Plant System Engineering Through Optimization Of Layout And Yaw Control, Paul Fleming, Andrew Ning, Pieter Gebraad, Katherine Dykes

Faculty Publications

Recent research has demonstrated exciting potential for wind plant control systems to improve the cost of energy of wind plants. Wind plant controls seek to improve global wind plant performance over control systems in which each turbine optimizes only its individual performance by accounting for the way wind turbines interact through their wakes. Although these technologies can be applied to existing wind plants, it is probable that the maximum benefit would be derived by designing wind plants with these capabilities in mind. In this paper, we use system engineering approaches to perform coupled wind plant controls and position layout optimizations …

Error-Compensation Method For Inclination Measurement Under The Influence Of The Dynamic Interference, Yanshun Zhang, Yajing Guo, Kui Li, Chaoying Pei, Ming Li

Mechanical and Aerospace Engineering Faculty Research & Creative Works

To deal with the problem of the inclination measurement errors caused by the dynamic motions, such as rotational and accelerated rectilinear components, this paper puts forward an effective inclination measurement scheme and the corresponding error-compensation method based on one accelerometer and two gyroscopes. In addition, the principal prototype of the dynamic inclination measurement apparatus is set up to conduct experiments of turntable rotation test, trolley test, and the turntable sway test at different inclined angles, thus verifying the feasibility of the error-compensation method under the effects of the rotational motion, accelerated rectilinear motion or both motions at the same time. …

Inversion Characteristics Of A Buoyant Cylindrical Puck During Oblique Water Impact, Zachary Crawford Smith

Theses and Dissertations

The Apollo Command Module had a tendency to flip over upon impact with the ocean surface after returning from space (9/19 times). In an effort to better characterize the inversion process for future water landing vehicles, experimental results for a simplified buoyant cylindrical puck impacting the water surface are presented. This study focuses on the dependence of inversion upon vertical velocity, horizontal velocity, and the pitch angle of the puck relative to the free surface. High-speed images reveal an asymmetric cavity that forms upon water impact. The asymmetric cavity then collapses, applying a moment, which can be sufficient to invert …

Theory, Fabrication, And Experimentation Of Phononic Crystals In Mems At Micro/Nano Scale: Engineering Of Thermal And Rf Phonons To Applications In Thermoelectrics And Microresonators, Seyedhamidreza Alaie

Mechanical Engineering ETDs

Phononic Crystals (PnCs) are novel materials comprised of a periodic structure of inclusions in a matrix. This periodic arrangement creates phononic bandgaps, and modifies phononic bandstructures of a material. Such a property offers promising applications at the micro and nano scales to engineer acoustic filters, high Q-factor resonators, and thermoelectric properties of materials. Studying PnCs at the micro/nano scale requires specific characterization techniques, which rely on Micro Electro Mechanical Structures (MEMS). This work focuses on the study, and characterization of PnCs using MEMS in view of their prospective applications in thermoelectric materials, microresonators and acoustic filters, and also the prospective …

Shock Wave Interaction With A Fluid Filled Cylinder Experimental Methods, Praveen Kumar Baba Siddabattuni

Theses

In the recent wars of Iraq and Afghanistan, many soldiers sustained bTBI (blast-induced traumatic brain injury). The blasts are created by extensive use of improvised explosive devices (IED’s). Whether pure blast-shock waves cause TBI or what is the mechanism of injury are not fully known. Research efforts are underway to find answers to these questions.

The primary objective of this project is to understand how the shockwave interacts with a fluid-filled cylinder of different thicknesses. Here, the cylinder is idealized as head and the fluid filled inside it as the brain material. The primary interest here is, how the pure …

Performance Metrics For Depth-Based Signal Separation Using Deep Vertical Line Arrays, Gabriel Paul Kniffin, John Kenneth Boyle, Lisa Zurk, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

A recent publication by McCargar and Zurk [(2013). J. Acoust. Soc. Am. 133(4), EL320–EL325] introduced a modified Fourier transform-based method for passive source depth estimation using vertical line arrays deployed below the critical depth in the deep ocean. This method utilizes the depth-dependent modulation caused by the interference between the direct and surface-reflected acoustic arrivals, the observation of which is enhanced by propagation through the reliable acoustic path. However, neither the performance of this method nor its limits of applicability have yet been thoroughly investigated. This paper addresses both of these issues; the first by identifying and analyzing the factors …

Relationship Between The Home Energy Score (Hes) And The Home Energy Rating System (Hers), Florida Solar Energy Center, Philip W. Fairey

FSEC Energy Research Center®

A significant cohort of approximately 2,900 registered home energy ratings using the REM/Rate HERS software tool, as reported to RESNET, are subjected to statistical analysis by the Dillon Group, Inc. The statistical analysis determines the distribution of HES results as a function of home energy efficiency as measured by the minimum standards of the 2009 IECC and by EPA’s ENERGY STAR program.

In addition, a parametric simulation analysis is conducted by the Florida Solar Energy Center using EnergyGauge® USA version 5.0, a RESNET-accredited HERS software tool, to determine the relationship between HES scores and the HERS Index. The parametric analysis …

Multimodal, Biomaterial-Focused Anticoagulation Via Superlow Fouling Zwitterionic Functional Groups Coupled With Anti-Platelet Nitric Oxide Release, Kagya Amoako, Harihara S. Sundaram, Ahmed Suhaib, Shaoyi Jiang, Keith E. Cook

Mechanical and Industrial Engineering Faculty Publications

The functions of anti-fouling, zwitterionic polycarboxybetaine (pCB) and anti-platelet nitric oxide (NO) release replicate key anticoagulant properties of the endothelium. The two approaches, only tested separately thus far, were paired on gas permeable polydimethylsiloxane (PDMS) membranes and evaluated for anti-coagulation. Uncoated PDMS (control) and PDMS coated with pCB were screened for fibrinogen (Fg) fouling followed by platelet adsorption testing to evaluate the effects of coating and/or NO using bioreactors. Bare or coated PDMS membranes separated sheep plasma (108 platelets/ml) and gas flow chambers within the bioreactors. Either 100 or 0 ppm of NO/N2 flowed through the gas chamber for NO …

Life Cycle Assessment And Optimization-Based Decision Analysis Of Construction Waste Recycling For A Leed-Certified University Building, Murat Kucukvar, Gokhan Egilmez, Omer Tatari

Mechanical and Industrial Engineering Faculty Publications

The current waste management literature lacks a comprehensive LCA of the recycling of construction materials that considers both process and supply chain-related impacts as a whole. Furthermore, an optimization-based decision support framework has not been also addressed in any work, which provides a quantifiable understanding about the potential savings and implications associated with recycling of construction materials from a life cycle perspective. The aim of this research is to present a multi-criteria optimization model, which is developed to propose economically-sound and environmentally-benign construction waste management strategies for a LEED-certified university building. First, an economic input-output-based hybrid life cycle assessment model …

Impacts Of Bias Correction Of Wind Forecasts On Hydrodynamic And Wave Model Predictions, Robert J. Weaver, Peyman Taeb, Bryan P. Holman, Steven M. Lazarus, Michael E. Splitt, Atousa Saberi, Jeff Colvin

Ocean Engineering and Marine Sciences Faculty Publications

High-resolution hydrodynamic models are forced by surface wind output from operational met. models. Current suite of operational met. models do not have the spatial resolution needed to resolve the fine scale processes associated with complex estuarine wind-driven circulation nor a detailed land-water mask. Goal: improve forecast wind forcing in most efficient manner as possible

The Relationship Between Intermittent Limit Cycles And Postural Instability Associated With Parkinson’S Disease, James R. Chagdes, Jessica E. Huber, Meredith Saletta, Meghan Darling-White, Arvind Raman, Shirley Rietdyk, Howard N. Zelaznik, Jeffrey M. Haddad

School of Mechanical Engineering Faculty Publications

Background: Many disease-specifc factors such as muscular weakness, increased muscle stiffness, varying postural strategies, and changes in postural refexes have been shown to lead to postural instability and fall risk in people with Parkinson’s disease (PD). Recently, analytical techniques, inspired by the dynamical systems perspective on movement control and coordination, have been used to examine the mechanisms underlying the dynamics of postural declines and the emergence of postural instabilities in people with PD. Methods: A wavelet-based technique was used to identify limit cycle oscillations (LCOs) in the anterior–posterior (AP) postural sway of people with mild PD (n = 10) compared …

Method For Hyper-Polarizing Nuclear Spns At Arbtrary Magnetic Felds, Carlos A. Meriles, Daniela Pagliero, Abdelghani Laraoui

Department of Mechanical and Materials Engineering: Faculty Publications

A method of dynamically polarizing the nuclear spin host of nitrogen-vacancy (NV) centers in diamond is provided. The method uses optical, microwave and radio-frequency pulses to recursively transfer spin polarization from the NV electronic spin. Nitrogen nuclear spin initialization approaching 80% at room temperature is demonstrated both in ensemble and single NV centers without relying on level anti-crossings. This makes the method applicable at arbitrary magnetic fields.

Field Tests Of Two Prestressed Concrete Girder Bridges For Live Load Distribution And Moment Continuity, Christopher D. Eamon, Alaa Chehab, Gustavo Parra-Montesinos

Civil and Environmental Engineering Faculty Research Publications

Two similar bridges constructed with a live load continuous connection were tested for live load distribution and joint continuity. Girder distribution factors (GDFs) were compared to AASHTO equivalent values. For positive moments on all girders as for negative moments on interior girders, results using AASHTO equivalent GDFs were found to be generally conservative. However, for negative moments on exterior girders, test results exceeded AASHTO values, with 2-lane results significantly so. GDF results were verified with a FEA model, which produced similar behavior to the field tests. With respect to joint continuity, it is estimated that a simple span would produce …

Reversible Plastic Events During Oscillatory Deformation Of Amorphous Solids, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

The effect of oscillatory shear strain on nonaffine rearrangements of individual particles in a three-dimensional binary glass is investigated using molecular dynamics simulations. The amorphous material is represented by the Kob-Andersen mixture at the temperature well below the glass transition. We find that during periodic shear deformation of the material, some particles undergo reversible nonaffine displacements with amplitudes that are approximately power-law distributed. Our simulations show that particles with large amplitudes of nonaffine displacement exhibit a collective behavior; namely, they tend to aggregate into relatively compact clusters that become comparable with the system size near the yield strain. Along with …

The Effects Of Thermal Procedure On Transformation Temperature, Crystal Structure And Microstructure Of Cu-Al-Co Shape Memory Alloy, Y. Aydoğdu, M. Kök, F. Dağdelen, A. Aydoğdu, Ali S. Turabi, Haluk E. Karaca

Mechanical Engineering Faculty Publications

The purpose of this study is to investigate the effects of different thermal procedures of the Cu-Al-Co shape memory alloy on its crystal structure, transformation temperature and microstructure. The alloys were subjected to a heat treatment and then cooling was applied at four different conditions. After the thermal process, XRD, DSC, optical microscopy and micro-hardness measurements were carried out. The experimental studies showed that crystal structure, microstructure and transformation temperature of Cu-Al-Co alloy were changed from the cooling conditions.

Assessment Of Force Coordination And Neuromuscular Quickness In Healthy Adults, Karen L. Haberland

Theses and Dissertations

Throughout daily life, it is necessary to handle and control innumerable objects. To do so, one’s hands must be precisely regulated. To ensure that an object is effectively manipulated, an individual must apply a grip force (GF) perpendicular to the object’s surface to overcome load force (LF), which acts tangential to the surface to counteract the object’s weight and inertia. Previous studies have shown an elaborate coordination between GF and LF in a variety of object manipulation tasks in healthy populations. This kinetic analysis is clinically important because the GF-LF coordination is shown to deteriorate in aging and neurologically impaired …

System And Method For Identifying Electrical Properties Of Integrate Circuits, Mary Y. Lanzerotti

AFIT Patents

A new method for displaying electrical properties for integrated circuit (IC) layout designs provides for improved human visualization of those properties and comparison of as designed layout design parameters to as specified layout design parameters and to as manufactured layout parameters. The method starts with a circuitry as designed layout in a first digital format, extracts values for electrical properties from that circuitry as designed layout then annotates those values back into the first digital format. The annotated circuitry as designed layout is then converted from the first digital format to a second digital format that can be converted to …

A Simulation Study Of A Radiofrequency Localization System For Tracking Patient Motion In Radiotherapy, Mark Ostyn, Siyong Kim, Woon-Hong Yeo

Mechanical and Nuclear Engineering Publications

One of the most widely used tools in cancer treatment is external beam radiotherapy. However, the major risk involved in radiotherapy is excess radiation dose to healthy tissue, exacerbated by patient motion. Here, we present a simulation study of a potential radiofrequency (RF) localization system designed to track intrafraction motion (target motion during the radiation treatment). This system includes skin-wearable RF beacons and an external tracking system. We develop an analytical model for direction of arrival measurement with radio frequencies (GHz range) for use in a localization estimate. We use a Monte Carlo simulation to investigate the relationship between a …

Effect Of Spalled Particles Thermal Degradation On A Hypersonic Flow Field Environment, Raghava S. C. Davuluri, Huaibao Zhang, Alexandre Martin

Mechanical Engineering Faculty Publications

Two-way coupling is performed between a spallation code and a hypersonic aerothermodynamics CFD solver to evaluate the effect of spalled particles on the flow field. Time accurate solutions are computed in argon and air flow fields. A single particle simulations and multiple particles simulations are performed and studied. The results show that the carbon vapor released by spalled particles tend to change the composition of the flow field, particularly the upstream region of the shock.

Orchard Bin Atv Trailer, Neil F. Leitz

All Undergraduate Projects

A local orchardist was experiencing a problem that was being caused by their lack of apple picking bin moving equipment. The orchardist needed a well-engineered solution to this lack of equipment. The solution arrived at was a five bin trailer. There were multiple design requirements for this trailer, including the device needing to be able to interface with an ATV, be able to be loaded by hand, be able to carry five bins, and not exceed a budget of $750. While perfecting the design of the trailer, a number of different disciplines were utilized, which included dynamics, kinematics, static loading …

Grant County Public Utilities District - Rotor Pole Lifting Device, Baylie Johnson

All Undergraduate Projects

Grant County Public Utilities District is planning a rehabilitation of all turbine and generator units at Priest Rapids Dam beginning in August 2016. After the generator rotor is removed from the unit, the rotor poles must be removed from the rotor. They are oriented vertically in the rotor and horizontally on the floor and in shipping containers. The objective of this project is to design, manufacture and test a lifting and a turning device for Priest Rapids Dam’s generator rotor poles. The lifting device was designed to attach a 3500 pound rotor pole to a crane and lift it. The …

Solar Water Heater: Mobile Stand, Tyson Nakamura

All Undergraduate Projects

During the course of this project, a solar thermal collector and supporting stand were designed and manufactured to be used during Mechanical Engineering Technology labs. Students will be able to use the collector to heat water, with the sun being the only heat source. The collector was designed by calculating surface area limitations, estimated solar input, and desired efficiency, to find the required water flow rate. From there, the necessary pipe lengths and diameters were determined, and the solar thermal collector was constructed. Two pipe paths were manufactured: a curved path, and a manifold path. Students will be able to …

Jeep Wj Multipurpose Oversize Spare Tire Carrier, Caleb J. Marrs

All Undergraduate Projects

OEM spare-tire wells have size limitations that only allow up to a certain size tire. However, the OEM tire well is not effective for the off-road enthusiast that needs an extra over size tire in case of an emergency. While off-roading it is important to be equipped with all the necessary tools and parts to get out safely because there is no roadside assistance off-road. The Jeep WJ is not a popular off road vehicle which means aftermarket accessories are not common. In order to optimize the space inside and out of the vehicle, a device is needed that will …