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Full-Text Articles in Mechanical Engineering

Analysis Of Inlet Distortion Patterns On Distortion Transfer And Generation Through A Highly Loaded Fan Stage, Andrew Dallin Orme Aug 2020

Analysis Of Inlet Distortion Patterns On Distortion Transfer And Generation Through A Highly Loaded Fan Stage, Andrew Dallin Orme

Theses and Dissertations

Characterization of distortion transfer and generation through fans with distorted inlet conditions enables progress towards designs with improved distortion tolerance. The abruptness of transition from undistorted to distorted total pressure regions at the inlet impacts the induced swirl profile and therefore the distortion transfer and generation. These impacts are characterized using URANS simulations of PBS Rotor 4 geometry under a variety of inlet distortion profiles. A 90° and a 135° sector, both of 15% total pressure distortion, are considered. Variants of each sector size, with decreasing levels of distortion transition abruptness, are each applied to the fan. Fourier-based distortion descriptors ...


On Creases And Curved Links: Design Approaches For Predicting And Customizing Behaviors In Origami-Based And Developable Mechanisms, Jared J. Butler Aug 2020

On Creases And Curved Links: Design Approaches For Predicting And Customizing Behaviors In Origami-Based And Developable Mechanisms, Jared J. Butler

Theses and Dissertations

This work develops models and tools to help designers address the challenges associated with designing origami-based and developable mechanisms. These models utilize strain energy, kinematics, compliant mechanisms, and graphical techniques to make the design of origami-based and developable mechanisms approachable and intuitive. Origami-based design tools are expanded through two methods. First presented is a generalized approach for identifying single-output mechanical advantage for a multiple-input compliant mechanism, such as many origami-based mechanisms. The model is used to predict the force-deflection behavior of an origami-based mechanism (Oriceps) and is verified with experimental data from magnetic actuation of the mechanism. Second is a ...


High-Fidelity Modeling Of Multirotor Aerodynamic Interactions For Aircraft Design, Eduardo Alvarez, Andrew Ning Aug 2020

High-Fidelity Modeling Of Multirotor Aerodynamic Interactions For Aircraft Design, Eduardo Alvarez, Andrew Ning

Faculty Publications

Electric aircraft technology has enabled the use of multiple rotors in novel concepts for urban air mobility. However, multirotor configurations introduce strong aerodynamic and aeroacoustic interactions that are not captured through conventional aircraft design tools. In this paper we explore the capability of the viscous vortex particle method (VPM) to model multirotor aerodynamic interactions at a computational cost suitable for conceptual design. A VPM-based rotor model is introduced along with recommendations for numerical stability and computational efficiency. Validation of the individual rotor is presented in both hovering and forward-flight configurations at low, moderate, and high Reynolds numbers. Hovering multirotor predictions ...


A Derivation Of Scattered Intensity (Radiance) For Use In Optical Particle Counters, Brady S. Hales, Matthew R. Jones, Randy S. Lewis Jul 2020

A Derivation Of Scattered Intensity (Radiance) For Use In Optical Particle Counters, Brady S. Hales, Matthew R. Jones, Randy S. Lewis

Student Works

Mie scattering theory is often used to calculate the flux of light scattered off of small particles whose diameter is approximately the same order of magnitude as the wavelength of incident light. In many equations for the calculation of this flux, it is assumed that the area of interest is perpendicular to the ray of scattered light. This assumption does not apply to all cases such as low-cost (


Tracking Joint Angles During Whole-Arm Movements Using Electromagnetic Sensors, Ryan Clark, Taylor Dickinson, Johnfredy Loaiza, Daniel W. Geiger, Steven Knight Charles Jul 2020

Tracking Joint Angles During Whole-Arm Movements Using Electromagnetic Sensors, Ryan Clark, Taylor Dickinson, Johnfredy Loaiza, Daniel W. Geiger, Steven Knight Charles

Faculty Publications

Electromagnetic (EM) motion tracking systems are suitable for many research and clinical applications, including in-vivo measurements of whole-arm movements. Unfortunately, the methodology for in vivo measurements of whole-arm movements using EM sensors is not well described in the literature, making it difficult to perform new measurements and all but impossible to make meaningful comparisons between studies. The recommendations of the International Society of Biomechanics (ISB) have provided a great service, but by necessity they do not provide clear guidance or standardization on all required steps. The goal of this paper was to provide a comprehensive methodology for using EM sensors ...


New Policies Give Solar Users An Economic Boost, Olivia Fowler May 2020

New Policies Give Solar Users An Economic Boost, Olivia Fowler

Marriott Student Review

The future looks bright for Solar Energy, as more States and Territories in the United States commit to moving to 100% renewable energy. What are the different states and territories committing to exactly, and what economic incentives are they bringing? Find out in this article by author Olivia Fowley.


3.8 Mm Thick Aluminum 5754-O Friction Stir Weld Data, Johnathon Hunt, Yuri Hovanski, Brian A. Mazzeo, Carl Sorensen Jan 2020

3.8 Mm Thick Aluminum 5754-O Friction Stir Weld Data, Johnathon Hunt, Yuri Hovanski, Brian A. Mazzeo, Carl Sorensen

ScholarsArchive Data

The data sets that are included are the following:

1) Raw measured data for 30 friction stir welds made from 5754-O aluminum alloy. (matlab .m file)

2) Radiographic images of the same welds.

(.tiff images)

3) Cross sectional images at certain location from some of the welds

(.jpeg)

4) An excel spread sheet that has a key to the data


Stainless-Steel Column For Robust High Temperature Microchip Gas Chromatography, Abhijit Ghosh, Austin R. Foster, Jacob C. Johnson, Carlos R. Vilorio, Luke T. Tolley, Brian D. Iverson, Aaron R. Hawkins, H. Dennis Tolley, Milton L. Lee Dec 2019

Stainless-Steel Column For Robust High Temperature Microchip Gas Chromatography, Abhijit Ghosh, Austin R. Foster, Jacob C. Johnson, Carlos R. Vilorio, Luke T. Tolley, Brian D. Iverson, Aaron R. Hawkins, H. Dennis Tolley, Milton L. Lee

Faculty Publications

This paper reports the first results of a robust, high performance, stainless-steel microchip gas chromatography (GC) column that is capable of analyzing complex real world mixtures as well as operating at very high temperatures. Using a serpentine design, a 10 m column with an approximately semicircular cross section with a 52 µm hydraulic diameter (Dh) was produced in a 17 cm x 6.3 cm x 0.1 cm rectangular steel chip. The channels were produced using a multilayer chemical etch and diffusion bonding process, and metal nuts were brazed onto the inlet and outlet ports allowing for column ...


Takeoff And Performance Tradeoffs Of Retrofit Distributed Electric Propulsion For Urban Transport, Kevin Moore, Andrew Ning Aug 2019

Takeoff And Performance Tradeoffs Of Retrofit Distributed Electric Propulsion For Urban Transport, Kevin Moore, Andrew Ning

Faculty Publications

While vertical takeoff and landing aircraft have shown promise for urban air transport, distributed electric propulsion on existing aircraft may offer immediately implementable alternatives. Distributed electric propulsion could potentially decrease takeoff distances enough to enable thousands of potential inter-city runways. This conceptual study explores the effects of a retrofit of open-bladed electric propulsion units. To model and explore the design space we use blade element momentum method, vortex lattice method, linear-beam finite element analysis, classical laminate theory, composite failure, empirically-based blade noise modeling, motor and motor-controller mass models, and gradient-based optimization. With liftoff time of seconds and the safe total ...


Simulated Tremor Propagation In The Upper Limb: From Muscle Activity To Joint Displacement, Thomas Corie, Steven Knight Charles Aug 2019

Simulated Tremor Propagation In The Upper Limb: From Muscle Activity To Joint Displacement, Thomas Corie, Steven Knight Charles

Faculty Publications

Although tremor is the most common movement disorder, there are few non-invasive treatment options. Creating effective tremor suppression devices requires a knowledge of where tremor originates mechanically (which muscles) and how it propagates through the limb (to which degrees of freedom, DOF).

To simulate tremor propagation, we created a simple model of the upper limb, with tremorogenic activity in the 15 major superficial muscles as inputs and tremulous joint displacement in the 7 major DOF as outputs. The model approximated the muscle excitation-contraction dynamics, musculoskeletal geometry, and mechanical impedance of the limb.

From our simulations, we determined fundamental principles for ...


Influence Of Micro-Structured Superhydrophobic Surfaces On Nucleation And Natural Convection In A Heated Pool, Adam Cowley, Daniel Maynes, Julie Crockett, Brian D. Iverson Feb 2019

Influence Of Micro-Structured Superhydrophobic Surfaces On Nucleation And Natural Convection In A Heated Pool, Adam Cowley, Daniel Maynes, Julie Crockett, Brian D. Iverson

Faculty Publications

This word experimentally explores sub-boiling pool nucleation on micro-structured superhydrophobic surfaces. All surfaces tested were submerged in a 20 mm deep pool of water and heated from below to maintain a constant surface temperature, while the side walls of the pool were insulated, and the top was covered. Three thermocouples positioned in the pool obtain the average pool temperature. A heat flux sensor is placed directly beneath the surface to measure the heat flux supplied to the pool. Free convection heat transfer coefficients are obtained for the sub-boiling temperature range of 40 – 90 ºC. Six surface types are studied: smooth ...


Optimization Of Turbine Design In Wind Farms With Multiple Hub Heights, Using Exact Analytic Gradients And Structural Constraints, Andrew P.J. Stanley, Andrew Ning, Katherine Dykes Jan 2019

Optimization Of Turbine Design In Wind Farms With Multiple Hub Heights, Using Exact Analytic Gradients And Structural Constraints, Andrew P.J. Stanley, Andrew Ning, Katherine Dykes

Faculty Publications

Wind farms are generally designed with turbines of all the same hub height. If wind farms were designed with turbines of different hub heights, wake interference between turbines could be reduced, lowering the cost of energy (COE). This paper demonstrates a method to optimize onshore wind farms with two different hub heights using exact, analytic gradients. Gradient-based optimization with exact gradients scales well with large problems and is preferable in this application over gradient-free methods. Our model consisted of the following: a version of the FLOw Redirection and Induction in Steady-State wake model that accommodated three- dimensional wakes and calculated ...


The Design, Construction, And Thermal Diffusivity Measurements Of The Fluorescent Scanning Thermal Microscope (Fstm), Samuel Hunter Hayden Dec 2018

The Design, Construction, And Thermal Diffusivity Measurements Of The Fluorescent Scanning Thermal Microscope (Fstm), Samuel Hunter Hayden

Theses and Dissertations

Over the life of nuclear fuel, inhomogeneous structures develop, negatively impacting thermal properties. New fuels are under development, but require more accurate knowledge of how the properties change to model performance and determine safe operational conditions. Measurement systems capable of small–scale, pointwise thermal property measurements and low cost are necessary to measure these properties and integrate into hot cells where electronics are likely to fail during fuel investigation. This project develops a cheaper, smaller, and easily replaceable Fluorescent Scanning Thermal Microscope (FSTM) using the blue laser and focusing circuitry from an Xbox HD-DVD player. The FSTM also incorporates novel ...


Investigation Of An Isotruss Structure As A Compliant Member Used In Bending And Torsion, Jens Garret Jacobson Dec 2018

Investigation Of An Isotruss Structure As A Compliant Member Used In Bending And Torsion, Jens Garret Jacobson

Theses and Dissertations

An investigation of IsoTruss structures in bending and torsion was conducted. A model was developed in ANSYS APDL where bay length and longitudinal member to helical member cross-sectional area ratio could be varied while holding the diameter constant. The model was validated using previously reported values from analytical models and empirical data. The model was used to make predictions of a specific geometry that was manufactured, tested and compared against the model. 12 specimens were built and tested. In flexure, empirical data had a percent error with respect to the model ranging from 10.9 to 65.4% with one ...


Origami-Based Design Of Fold States And Stability, Alex Avila Dec 2018

Origami-Based Design Of Fold States And Stability, Alex Avila

Theses and Dissertations

Origami is a potentially elegant and powerful source of inspiration for many engineering designs. The viable shapes (fold states) of a single device allow it to perform multiple, seemingly contradictory, functions. The fold state is a large factor in the device's performance, but there are challenges in selecting and maintaining those fold states. In this thesis we analyze existing concepts for overcoming these challenges. Those concepts are compared with those that occur in origami-based devices. From this analysis fundamental gaps were identified, specifically, shortcoming in the terminology used to refer to (1) non-flat origami states and (2) sets of ...


Estimation Of Knee Kinematics Using Non-Monotonic Nanocomposite High-Deflection Strain Gauges, Adin Douglas Martineau Dec 2018

Estimation Of Knee Kinematics Using Non-Monotonic Nanocomposite High-Deflection Strain Gauges, Adin Douglas Martineau

Theses and Dissertations

Human knee kinematics, especially during gait, are an important analysis tool. The current "gold standard" for kinematics measurement is a multi-camera, marker-based motion capture system with 3D position tracking. These systems are accurate but expensive and their use is limited to a confined laboratory environment. High deflection strain gauges (HDSG) are a novel class of sensors that have the potential to measure kinematics and can be inexpensive, low profile, and are not limited to measurements within a calibrated volume. However, many HDSG sensors can have a non-linear and non-monotonic response. This thesis explores using a nanocomposite HDSG sensor system for ...


Examining The Mechanics Responsible For Strain Delocalization In Metallic Glass Matrix Composites, Casey Owen Messick Dec 2018

Examining The Mechanics Responsible For Strain Delocalization In Metallic Glass Matrix Composites, Casey Owen Messick

Theses and Dissertations

Metallic glass matrix composites (MGMCs) have been developed to improve upon the ductility of monolithic metallic glass. These composites utilize a secondary crystalline phase that is grown into an amorphous matrix as isolated dendritic trees. This work seeks to understand the mechanisms underlying strain delocalization in MGMCs in order to better direct efforts for continual progress in this class of material. A mesoscale modelling technique based on shear transformation zone (STZ) dynamics is used to do so. STZ dynamics is a coarse grained technique that can provide insight into the microscopic processes that control macroscopic behavior, but which can be ...


Distributed Electric Propulsion Conceptual Design Applied To Traditional Aircraft Take Off Distance Through Multidisciplinary Design, Kevin Ray Moore Nov 2018

Distributed Electric Propulsion Conceptual Design Applied To Traditional Aircraft Take Off Distance Through Multidisciplinary Design, Kevin Ray Moore

Theses and Dissertations

While vertical takeoff and landing aircraft show promise for urban air transport, distributed electric propulsion on existing aircraft may offer an immediately implementable alternative. Dis- tributed electric propulsion has the potential of increasing the aircraft thrust-to-weight ratio and lift coefficient high enough to enable takeoff distances of less than 100 meters. While fuel based propulsion technologies generally increase in specific power with increasing size, electric propul- sion typically can be decreased in size without a decrease in specific power. The smaller but highly power-dense propulsion units enable alternative designs including many small units, optionally powered units, and vectored thrust from ...


Cip2a Immunosensor Comprised Of Vertically-Aligned Carbon Nanotube Interdigitated Electrodes Towards Point-Of-Care Oral Cancer Screening, Shaowei Ding, Suprem R. Das, Benjamin J. Brownlee, Kshama Parate, Taylor Davis, Loreen R. Stromberg, Edward K.L. Chan, Joseph Katz, Brian D. Iverson, Jonathan C. Claussen Oct 2018

Cip2a Immunosensor Comprised Of Vertically-Aligned Carbon Nanotube Interdigitated Electrodes Towards Point-Of-Care Oral Cancer Screening, Shaowei Ding, Suprem R. Das, Benjamin J. Brownlee, Kshama Parate, Taylor Davis, Loreen R. Stromberg, Edward K.L. Chan, Joseph Katz, Brian D. Iverson, Jonathan C. Claussen

Faculty Publications

Vertically aligned carbon nanotube array (VANTA) coatings have recently garnered much attention due in part to their unique material properties including light absorption, chemical inertness, and electrical conductivity. Herein we report the first use of VANTAs grown via chemical vapor deposition in a 2D interdigitated electrode (IDE) footprint with a high height-to-width aspect ratio (3:1 or 75:25 µm). The VANTA-IDE is functionalized with an antibody (Ab) specific to the human cancerous inhibitor PP2A (CIP2A)—a alivary oncoprotein that is associated with a variety of malignancies such as oral, breast, and multiple myeloma cancers. The resultant immunosensor is capable ...


Coordinated, Multi-Arm Manipulation With Soft Robots, Dustan Paul Kraus Oct 2018

Coordinated, Multi-Arm Manipulation With Soft Robots, Dustan Paul Kraus

Theses and Dissertations

Soft lightweight robots provide an inherently safe solution to using robots in unmodeled environments by maintaining safety without increasing cost through expensive sensors. Unfortunately, many practical problems still need to be addressed before soft robots can become useful in real world tasks. Unlike traditional robots, soft robot geometry is not constant but can change with deflation and reinflation. Small errors in a robot's kinematic model can result in large errors in pose estimation of the end effector. This error, coupled with the inherent compliance of soft robots and the difficulty of soft robot joint angle sensing, makes it very ...


Deep Rc: Enabling Remote Control Through Deep Learning, Jaron Ellingson, Gary Ellingson, Tim Mclain Sep 2018

Deep Rc: Enabling Remote Control Through Deep Learning, Jaron Ellingson, Gary Ellingson, Tim Mclain

Student Works

Human remote-control (RC) pilots have the ability to perceive the position and orientation of an aircraft using only third-person-perspective visual sensing. While novice pilots often struggle when learning to control RC aircraft, they can sense the orientation of the aircraft with relative ease. In this paper, we hypothesize and demonstrate that deep learning methods can be used to mimic the human ability to perceive the orientation of an aircraft from monocular imagery.

This work uses a neural network to directly sense the aircraft attitude. The network is combined with more conventional image processing methods for visual tracking of the aircraft ...


Thermal Transport At Superhydrophobic Surfaces In Impinging Liquid Jets, Natural Convection, And Pool Boiling, Matthew Clark Searle Sep 2018

Thermal Transport At Superhydrophobic Surfaces In Impinging Liquid Jets, Natural Convection, And Pool Boiling, Matthew Clark Searle

Theses and Dissertations

This dissertation focuses on the effects of superhydrophobic (SHPo) surfaces on thermal transport. The work is divided into two main categories: thermal transport without phase change and thermal transport with phase change. Thermal transport without phase change is the topic of four stand-alone chapters. Three address jet impingement at SHPo surfaces and the fourth considers natural convection at a vertical, SHPo wall. Thermal transport with phase change is the topic of a single stand-alone chapter exploring pool boiling at SHPo surfaces. Two chapters examining jet impingement present analytical models for thermal transport; one considered an isothermal wall and the other ...


Visual Servoing For Multirotor Precision Landing In Varying Light Conditions, Jesse Wynn, Tim Mclain Aug 2018

Visual Servoing For Multirotor Precision Landing In Varying Light Conditions, Jesse Wynn, Tim Mclain

Faculty Publications

The problem of performing a precision landing of an autonomous multirotor UAV in various lighting conditions is studied. A vision-based approach is proposed and consists of varying degree-of-freedom image-based visual servoing (VDOF-IBVS), and a specialized landing marker. The proposed approach is validated through extensive flight testing outdoors in both lighted and dark conditions, and is done using a standard off-the-shelf autopilot system.


Developable Compliant-Aided Rolling-Contact Mechanisms, Todd G. Nelson, Just L. Herder Aug 2018

Developable Compliant-Aided Rolling-Contact Mechanisms, Todd G. Nelson, Just L. Herder

Student Works

Rolling-contact mechanisms can provide low-friction motion with unique kinematic paths. We show that developable surfaces can be used as a design tool for rolling-contact mechanisms joined with compliant bands. These mechanisms can exhibit 3D motion paths, couple rotational and translational motions into a single degree of freedom, and can be designed to exhibit various tailored kinetic responses. We set forth developable surface parametrizations well suited to the creation of rolling contacts. We highlight how the geodesic and principal curvatures of the non-ruling principal curves of a developable surface are meaningful design quantities for rolling contacts. We provide kinematic and kinetic ...


Methods And Metrics To Measure And Predict The Social Impact Of Engineered Products, Phillip Douglas Stevenson Aug 2018

Methods And Metrics To Measure And Predict The Social Impact Of Engineered Products, Phillip Douglas Stevenson

Theses and Dissertations

More than ever before, engineers are creating products for developing countries. One of the purposes of these products is to improve the consumer's quality of life. Currently, there is no established method of measuring the social impact of these types of products. As a result, engineers have used their own metrics to assess their product's impact, if at all. Some of the common metrics used include products sold and revenue, which measure the financial success of a product without recognizing the social successes or failures it might have. In this thesis I introduce a potential metric, the Product ...


Efficient Incorporation Of Fatigue Damage Constraints In Wind Turbine Blade Optimization, Bryce Taylor Ingersoll Aug 2018

Efficient Incorporation Of Fatigue Damage Constraints In Wind Turbine Blade Optimization, Bryce Taylor Ingersoll

Theses and Dissertations

Improving the wind turbine blade design has a significant effect on the efficiency of the wind turbine. This is a challenging multi-disciplinary optimization problem. During the blade design process, the aerodynamic shapes, sizing of the structural members, and material composition must all be determined and optimized. Some previous blade design methods incorporate the wind turbine's static response with an added safety factor to account for neglected dynamic effects. Others incorporate the dynamic response, but in general is limited to a few design cases. By not fully incorporating the dynamic response of the wind turbine, the final turbine ...


Electrochemical Glucose Sensors Enhanced By Methyl Viologen And Vertically Aligned Carbon Nanotube Channels, Benjamin J. Brownlee, Meisam Bahari, John H. Harb, Jonathan C. Claussen, Brian D. Iverson Aug 2018

Electrochemical Glucose Sensors Enhanced By Methyl Viologen And Vertically Aligned Carbon Nanotube Channels, Benjamin J. Brownlee, Meisam Bahari, John H. Harb, Jonathan C. Claussen, Brian D. Iverson

Faculty Publications

Free-standing, vertically aligned carbon nanotubes (VACNTs) were patterned into 16 μm diameter microchannel arrays for flow-through electrochemical glucose sensing. Non-enzymatic sensing of glucose was achieved by the chemical reaction of glucose with methyl viologen (MV) at an elevated temperature and pH (0.1 M NaOH), followed by the electrochemical reaction of reduced-MV with the VACNT surface. The MV sensor required no functionalization (including no metal) and was able to produce on average 3.4 electrons per glucose molecule. The current density of the MV sensor was linear with both flow rate and glucose concentration. Challenges with interference chemicals were mitigated ...


Design For Maintainability In Developing Communities—A Case Study On The Uros Islands, Thomas Barlow Jul 2018

Design For Maintainability In Developing Communities—A Case Study On The Uros Islands, Thomas Barlow

Undergraduate Honors Theses

Designing products for developing communities has exposed many of the underlying assumptions that engineers from developed nations have during the design process. There has been much written about these underlying assumptions in order to create a better framework for designing for developing communities. One unexplored, yet important area is the universality of common maintainability principles used in developed countries when designing products used in developing communities. Such principles include: simplicity, diagnosability, standardization of parts, modular subassemblies, minimizing assembly and disassembly parts, labeling components, increased life of moving parts, manuals, and simplifying tools needed for repairs [1]–[3]. The purpose of ...


Tactile Sensing And Position Estimation Methods For Increased Proprioception Of Soft-Robotic Platforms, Nathan Mcclain Day Jul 2018

Tactile Sensing And Position Estimation Methods For Increased Proprioception Of Soft-Robotic Platforms, Nathan Mcclain Day

Theses and Dissertations

Soft robots have the potential to transform the way robots interact with their environment. This is due to their low inertia and inherent ability to more safely interact with the world without damaging themselves or the people around them. However, existing sensing for soft robots has at least partially limited their ability to control interactions with their environment. Tactile sensors could enable soft robots to sense interaction, but most tactile sensors are made from rigid substrates and are not well suited to applications for soft robots that can deform. In addition, the benefit of being able to cheaply manufacture soft ...


Total Hemispherical Apparent Radiative Properties Of The Infinite V-Groove With Diffuse Reflection, Rydge B. Mulford, Nathan S. Collins, Michael S. Farnsworth, Matthew R. Jones, Brian D. Iverson Jul 2018

Total Hemispherical Apparent Radiative Properties Of The Infinite V-Groove With Diffuse Reflection, Rydge B. Mulford, Nathan S. Collins, Michael S. Farnsworth, Matthew R. Jones, Brian D. Iverson

Faculty Publications

No abstract provided.