Engineering Commons^™

Proactive Energy Optimization In Residential Buildings With Weather And Market Forecasts, Cody Simmons, Joshua Arment, Kody M. Powell, John Hedengren

Faculty Publications

This work explores the development of a home energy management system (HEMS) that uses weather and market forecasts to optimize the usage of home appliances and to manage battery usage and solar power production. A Moving Horizon Estimation (MHE) application is used to find the unknown home model parameters. These parameters are then updated in a Model Predictive Controller (MPC) which optimizes and balances competing comfort and economic objectives. Combining MHE and MPC applications alleviates model complexity commonly seen in HEMS by using a lumped parameter model that is adapted to fit a high-fidelity model. Heating, ventilation, and air conditioning …

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 (D_h) 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 interfacing …

A Review Of 30 Years Of Research Using The Cpd Model, Thomas H. Fletcher

Faculty Publications

The chemical percolation devolatilization (CPD) model for coal pyrolysis was first published in 1989, and a completed version that included the vapor–liquid equilibrium model and cross-linking model was published in 1992. The CPD model was one of three pyrolysis models developed using a lattice model to account for the chemical structure of the coal and was directly based on solid-state ¹³C nuclear magnetic resonance (NMR) measurements of the coal structure. A correlation of coal structure parameters measured by NMR spectroscopy was performed to permit use of the CPD model to determine pyrolysis rates and yields of tars and light …

Average Speech Directivity, Samuel D. Bellows, Claire M. Pincock, Jennifer K. Whiting, Timothy W. Leishman

Directivity

Speech directivity describes the angular dependence of acoustic radiation from a talker’s mouth and nostrils and diffraction about his or her body and chair (if seated). It is an essential physical aspect of communication affecting sounds and signals in acoustical environments, audio, and telecommunication systems. Because high-resolution, spherically comprehensive measurements of live, phonetically balanced speech have been unavailable in the past, the authors have undertaken research to produce and share such data for simulations of acoustical environments, optimizations of microphone placements, speech studies, and other applications. The measurements included three male and three female talkers who repeated phonetically balanced passages …

An Open-Source Tool To Facilitate The Processing Of Grace Observations And Gldas Outputs: An Evaluation In Bangladesh, Adam J. Purdy, Cédric H. David, Md. Safat Sikder, John T. Reager, Hrishikesh A. Chandanpukar, Norman L. Jones, Mir A. Matin

Faculty Publications

Bangladesh lies at the intersection of the Ganges, Brahmaputra, and Meghna rivers with a combined average discharge of 38,000 m3s−1 ranking fourth globally. Despite the volume of water flowing through and seasonally inundating parts of the landscape, groundwater reliance is necessary to support an intensive agricultural industry. Here we use newly-developed open-source software to combine observations from the Gravity Recovery and Climate Experiment (GRACE) satellites with hydrologic estimates of land water storage from the Global Land Assimilation Data System (GLDAS) to isolate basin-scale groundwater anomalies in Northwest Bangladesh from 2002 to 2016. We place our estimates in the context of …

Hydrologic Modeling As A Service (Hmaas): A New Approach To Address Hydroinformatic Challenges In Developing Countries, Michael A. Souffront Alcantara, E. James Nelson, Kiran Shakya, Christopher Edwards, Wade Roberts, Corey Krewson, Daniel P. Ames, Norman L. Jones, Angelica Gutierrez

Faculty Publications

Hydrologic modeling can be used to aid in decision-making at the local scale. Developed countries usually have their own hydrologic models; however, developing countries often have limited hydrologic modeling capabilities due to factors such as the maintenance, computational costs, and technical capacity needed to run models. A global streamflow prediction system (GSPS) would help decrease vulnerabilities in developing countries and fill gaps in areas where no local models exist by providing extensive results that can be filtered for specific locations. However, large-scale forecasting systems come with their own challenges. These New hydroinformatic challenges can prevent these models from reaching their …

Enabling Stakeholder Decision-Making With Earth Observation And Modeling Data Using Tethys Platform, E. James Nelson, Sarva T. Pulla, Mir A. Matin, Kiran Shakya, Norm Jones, Daniel P. Ames, W. Lee Ellenburg, Kel N. Markert, Cédric H. David, Benjamin F. Zaitchik, Patrick Gatlin, Riley Hales

Faculty Publications

Tethys Platform is an open source framework for developing web-based applications for Earth Observation data. Our experience shows that Tethys significantly lowers the barrier for cloud-based app development, simplifies the process of accessing scalable distributed cloud computing resources and leverages additional software for data and computationally intensive modeling. The Tethys software development kit allows users to create web apps for visualizing, analyzing, and modeling Earth Observation data. Tethys platform provides a collaborative environment for scientists to develop and deploy several Earth Observation web applications across multiple Tethys portals. We work in partnership with leading regional organizations world-wide to help developing …

Wind Farm Layout Optimization With Loads Considerations, Andrew P. J. Stanley, Jennifer King, Andrew Ning

Faculty Publications

The objective of this paper is to improve the annual energy production of a wind farm by optimizing the layout of a wind farm, while considering fatigue loads on turbines. In this paper, the loads are estimated using the edgewise bending moment computed using CCBlade, a steady-state blade element momentum code. The edgewise bending moment is then used to calculate fatigue damage using Miner’s rule. The fatigue damage is used to constrain the layout optimization problem. We show that our method can predict blade root damage with similar trends to damage calculated with other methods, such as a complex, computationally …

Adhesion Testing Of Printed Inks While Varying The Surface Treatment Of Polymer Substrates, Clayton Neff, Edwin Elston, Amanda Schrand, Nathan B. Crane

Faculty Publications

Additive manufacturing with conductive materials enables new approaches to printed electronics that are unachievable by standard electronics manufacturing processes. In particular, electronics can be embedded directly into structural components in nearly arbitrary 3D space. While these methods incorporate many of the same materials, the new processing methods require standard test methods to compare materials, processing conditions, and determine design limits. This work demonstrates a test method to quantitatively measure the adhesion failure of printed inks deposited on a substrate without changing the ink printing conditions. The proposed method is an adaption of single lap shear testing in which the lap …

Mechanical And Temperature Resilience Of Multi-Material Systems For Printed Electronics Packaging, Clayton Neff, Justin Nussbaum, Chris Gardiner, Nathan B. Crane, James L. Zunino, Mike Newton

Faculty Publications

In this work, two AM technologies were utilized to compare the effectiveness of fabricating a simple electronic device with a conductive trace and hollow cylinder representative of ‘printed packaging’ that would survive harsh environmental conditions. The printed packaging cylinder delineates printed potting for electronics packaging. An nScrypt direct write (DW) system was the primary manufacturing system but a developing technology—coined large area projection sintering (LAPS)—manufactured a subset of samples for comparison. The tests follow Military Standard (MIL STD) 883K and include resiliency evaluation for die shear strength, temperature cycling, thermal shock, and high G loading by mechanical shock. Results indicate …

Characterization Of Mechanical Properties Of Thin-Film Li-Ion Battery Electrodes From Laser Excitation And Measurements Of Zero Group Velocity Resonances, Jing Yao, Joseph Cassler, Dean R. Wheeler, Brian A. Mazzeo

Faculty Publications

The mechanical properties of thin-film Li-ion battery electrodes are controlled by the microstructure of the constituent materials. In this work, a noncontact and nondestructive measurement of the mechanical properties of electrode films is performed by measurement of zero-group velocity (ZGV) resonances. Theoretical models are used to quantify the sensitivity of the ZGV resonances to changes in mechanical properties. The ZGV Lamb modes of a solid bilayer consisting of a thin metallic layer and a thin compliant coating layer are shown to be dependent on Young’s moduli, thicknesses, densities, and Poisson’s ratios of the layers. Experimental ZGV resonances are excited using …

Generalized Beam–Spring Model For Predicting Elastic Behavior Of Partially Composite Concrete Sandwich Wall Panels, Salam Al-Rubaye, Taylor Sorensen, Robert J. Thomas, Marc Maguire

Faculty Publications

Partially composite sandwich wall panels (SWP) have been used in the construction industry for at least twenty years. Currently there is limited codified guidance for designers of partially composite concrete SWP, but they are being designed safely and routinely. Design is often guided by the composite connector manufacturers who sell proprietary composite connectors often using a variation of truss-type matrix methods for prediction of elastic behavior of SWPs. The purpose of this paper is to quantify the accuracy of such a model in a uniform manner by developing a generalized version of these matrix models called the beam-spring model (BSM). …

Relative Navigation Of Fixed-Wing Aircraft In Gps-Denied Environments, Gary J. Ellingson, Kevin M. Brink, Timothy Mclain

Faculty Publications

The future impact of small unmanned aircraft will depend in part on how well they can navigate in GPS-denied and GPS-degraded environments. While several GPS-denied navigation methods have been introduced, small fixed-wing aircraft have, for the most part, been neglected. This paper introduces a method to enable GPS-denied fixed-wing flight while accounting for fixed-wing-specific sensing requirements. This work uses a methodology called relative navigation as an overarching framework. The development of an odometry-like, front-end, EKF-based estimator that utilizes only a monocular camera and an inertial measurement unit is presented. The filter uses the measurement model of the multi-state-constraint Kalman filter. …

Wetting Metamorphosis Of Hydrophobic Fluoropolymer Coatings Submerged In Water And Ultrasonically Vibrated, Matthew Trapuzzano, Nathan B. Crane, Rasim Guldiken, Andrés Tejada-Martínez

Faculty Publications

Many important processes, from manufacture of integrated circuit boards, to an insect’s ability to walk on water, depend on the wetting of liquids on surfaces. Wetting is commonly controlled through material selection, coatings, and/or surface texture. However, wetting is sensitive to environmental conditions. In particular, some hydrophobic fluoropolymer coatings are sensitive to extended water exposure as evidenced by a declining contact angle and increasing contact angle hysteresis. Understanding “degradation” of these coatings is critical to applications that employ them. The durability of a series of fluoropolymer coatings were tested by measuring the contact angle before, during, and after extended submersion …

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 …

Binder Jetting: A Review Of Process, Materials, And Methods, Mohsen Ziaee, Nathan B. Crane

Faculty Publications

Binder Jet printing is an additive manufacturing technique that dispenses liquid binding agent on powder. Layers are formed repeatedly to build up a physical article. Binder jetting (BJ) can be adapted to almost any powder with high production rates. The BJ process utilizes a broad range of technologies including printing methods, powder deposition, dynamic binder/powder interaction, and post-processing methods. A wide variety of materials have been demonstrated including polymers, metals, and ceramics, but a common challenge is developing printing and post-processing methods that maximize part performance. This article presents a broad review of technologies and approaches that have been applied …

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 …

Heat Set Creases In Polyethylene Terephthalate (Pet)Sheets To Enable Origami-Based Applications, Larry L. Howell, Nathan C. Brown, Brandon S. Sargent, Brian D. Jensen, Spencer P. Magleby, William G. Pitt

ScholarsArchive Data

This data set includes the raw data from the tests described in the research paper “Heat Set Creases in Polyethylene Terephthalate (PET) Sheets to Enable Origami-Based Applications” by Brandon Sargent, Nathan Brown, Brian D. Jensen, Spencer P. Magleby, William G. Pitt, and Larry L. Howell.

Achieving Tiered Model Quality In 3d Structure From Motion Models Using A Multi-Scale View-Planning Algorithm For Automated Targeted Inspection, Trent Okeson, Benjamin Barrett, Samuel Arce, Cory Vernon, Kevin W. Franke, John Hedengren

Faculty Publications

This study presents a novel multi-scale view-planning algorithm for automated targeted inspection using unmanned aircraft systems (UAS). In industrial inspection, it is important to collect the most relevant data to keep processing demands, both human and computational, to a minimum. This study investigates the viability of automated targeted multi-scale image acquisition for Structure from Motion (SfM)-based infrastructure modeling. A traditional view-planning approach for SfM is extended to a multi-scale approach, planning for targeted regions of high, medium, and low priority. The unmanned aerial vehicle (UAV) can traverse the entire aerial space and facilitates collection of an optimized set of views, …

Sequential Earthquake Damage Assessment Incorporating Optimized Suav Remote Sensing At Pescara Del Tronto, Michael Freeman, Cory Vernon, Benjamin Barrett, Nicole Hastings, Jeff Derricott, Janessa Pace, Benjamin Horne, Joshua Hammond, Joseph Janson, Filiberto Chiabrando, John Hedengren, Kevin W. Franke

Faculty Publications

A sequence of large earthquakes in central Italy ranging in moment magnitudes (Mw) from 4.2 to 6.5 caused significant damage to many small towns in the area. After each earthquake in 2016 (24 August and 26 October), automated small unmanned aerial vehicles (sUAV) acquired valuable imagery data for post-hazard reconnaissance in the mountain village of Pescara del Tronto, and were applied to 3D reconstruction using Structure-from-Motion (SfM). In July 2018, the site was again monitored to obtain additional imagery data capturing changes since the last visit following the 30 October 2016 Earthquake. A genetic-based mission-planning algorithm that delivers optimal viewpoints …

An Examination Into The Defining Characteristics Of Flexible Solar Aircraft Configurations Through Optimization, Taylor Mcdonnell, Andrew Ning

Faculty Publications

This paper examines the defining characteristics of various solar aircraft configurations through gradient-based multidisciplinary design optimization. We first present a general gradient-based solar aircraft optimization framework which accounts for nonlinear aeroelastic effects resulting from structural flexibility. We then apply this framework to several discrete SR- HALE aircraft geometric, structural, and propulsion system configuration choices to determine the defining characteristics of each configuration choice.

Development Of A Parameterized Reduced-Order Vertical-Axis Wind Turbine Wake Model, Eric Tingey, Andrew Ning

Faculty Publications

Analyzing or optimizing wind farm layouts often requires reduced-order wake models to estimate turbine wake interactions and wind velocity. We propose a wake model for vertical-axis wind turbines (VAWTs) in streamwise and crosswind directions. Using vorticity data from computational fluid dynamic (CFD) simulations and cross-validated Gaussian distribution fitting, we produced a wake model that can estimate normalized wake velocity deficits of an isolated VAWT using normalized downstream and lateral positions, tip-speed ratio, and solidity. Compared to CFD, taking over a day to run one simulation, our wake model predicts a velocity deficit in under a second with an appropriate accuracy …

Modeling Multirotor Aerodynamic Interactions Through The Vortex Particle Method, Eduardo Alvarez, Andrew Ning

Faculty Publications

Distributed electric propulsion and vertical take-off and landing has recently opened a new design space for urban air mobility. However, the use of multiple rotors operating in close proximity introduces complicated aerodynamic interactions that are not well understood, are not captured through conventional design tools, and need to be addressed in the conceptual design stage. This study investigates the accuracy of the viscous vortex particle method (VPM) in modeling rotor-on-rotor aerodynamic interactions in a side- by-side configuration as encountered in tilt-rotor, quadrotor, and distributed propulsion aircraft. The VPM approach has the potential to enable the use of mid/high fidelity models …

An Iterative Five-Point Algorithm With Application To Multi-Target Tracking, Jacob H. White, Randal W. Beard

Student Works

We present ReSORtSAC: Recursively-seeded optimization, refinement, sample, and consensus. ReSORtSAC is a novel algorithm that can be used to estimate the relative pose between consecutive frames of a video sequence. Relative pose estimation algorithms typically generate a large number of hypotheses from minimum subsets and score them in order to be robust to noise and outliers. The relative pose is often represented using the essential matrix. Previous methods calculate essential matrix hypotheses directly without utilizing prior information. These equations are complex to evaluate and can return up to ten essential matrix solutions for each minimum subset, all of which must …

The Homography As A State Transformation Between Frames In Visual Multi-Target Tracking, Jacob H. White, Randal W. Beard

Student Works

No abstract provided.

Mass-Transfer Driven Spinodal Decomposition In A Ternary Polymer Solution, Douglas R. Tree, Lucas F. Dos Santos, Caden B. Wilson, Timothy R. Scott, Jan Ulric Garcia, Glenn H. Fredrickson

Faculty Publications

Nonsolvent induced phase separation (NIPS) is a widely occuring process used in industrial membrane production, nanotechnology and Nature to produce microstructured polymer materials. A variety of process-dependent morphologies are produced when a polymer solution is exposed to a nonsolvent that, following a period where mass is exchanged, precipitates and solidifies the polymer. Despite years of investigation, both experimental and theoretical, many questions surround the pathways to the microstructures that NIPS can produce. Here, we provide simulation results from a model that simultaneously captures both the processess of solvent/nonsolvent exchange and phase separation. We show that the time it takes the …

Impact Of Pulse Length On The Accuracy Of Defect Depth Measurements In Pulse Thermography, James Pierce, Nathan B. Crane

Faculty Publications

Pulse thermography is a nondestructive testing method in which an energy pulse is applied to a surface while the surface temperature evolution is measured to detect sub surface defects and estimate their depth. This nondestructive test method was developed on the assumption of instantaneous surface heating, but recent work has shown that relatively long pulses can be used to accurately determine defect depth in polymers. This paper examines the impact of varying input pulse length on the accuracy of defect depth quantification as a function of the material properties. Simulations using both thermoplastics and metals show that measurement error is …

Developable Mechanisms On Developable Surfaces, Todd G. Nelson, Trent K. Zimmerman, Robert J. Lang, Spencer P. Magleby, Larry L. Howell

Faculty Publications

The trend toward smaller mechanism footprints and volumes, while maintaining the ability to perform complex tasks, presents the opportunity for exploration of hypercompact mechanical systems integrated with curved surfaces. Developable surfaces are shapes that a flat sheet can take without tearing or stretching, and they represent a wide range of manufactured surfaces. This work introduces “developable mechanisms” as devices that emerge from or conform to developable surfaces. They are made possible by aligning hinge axes with developable surface ruling lines to enable mobility. Because rigid-link motion depends on the relative orientation of hinge axes and not link geometry, links can …

Model Predictive Automatic Control Of Sucker Rod Pump System With Simulation Case Study, Brigham Hansen, Brandon Tolbert, Cory Vernon, John Hedengren

Faculty Publications

This work enables accelerated fluid recovery in oil and gas reservoirs by automatically controlling fluid height and bottomhole pressure in wells. Several literature studies show significant increase in recovered oil by determining a target bottomhole pressure but rarely consider how to control to that value. This work enables those benefits by maintaining bottomhole pressure or fluid height. Moving Horizon Estimation (MHE) determines uncertain well parameters using only common surface measurements. A Model Predictive Controller (MPC) adjusts the stroking speed of a sucker rod pump to maintain fluid height. Pump boundary conditions are simulated with Mathematical Programs with Complementarity Constraints (MPCCs) …

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: …