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Full-Text Articles in Engineering

Proactive Energy Optimization In Residential Buildings With Weather And Market Forecasts, Cody Simmons, Joshua Arment, Kody M. Powell, John Hedengren Dec 2019

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 …


A Review Of 30 Years Of Research Using The Cpd Model, Thomas H. Fletcher Nov 2019

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 …


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 Jun 2019

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 Jun 2019

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 …


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 Apr 2019

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 …


Model Predictive Automatic Control Of Sucker Rod Pump System With Simulation Case Study, Brigham Hansen, Brandon Tolbert, Cory Vernon, John Hedengren Feb 2019

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) …


Correlations Of The Elemental Compositions Of Primary Coal Tar And Char, Andrew P. Richards, Colson Johnson, Thomas H. Fletcher Jan 2019

Correlations Of The Elemental Compositions Of Primary Coal Tar And Char, Andrew P. Richards, Colson Johnson, Thomas H. Fletcher

Faculty Publications

Simulations of large-scale coal combustors rely on accurate submodels to describe the chemical and physical changes in coal during reaction. Typically, simplified empirical submodels are tuned to experimental data to reduce the computational complexity. When data are not readily available, simplifying assumptions are used, which can create inaccuracies and biases in a large simulation. One such simplifying assumption in coal research is how to describe the elemental composition of primary pyrolysis products. This paper explores several different empirical model forms to predict the dry, ash-free fractions of C, H, O, N, and S in both the char and tar, using …


Heating Rate And Temperature Effects On Pyrolysis Products From Live Wildland Fuels, Mohammad-Saeed Safdari, Elham Amini, David R. Weise, Thomas H. Fletcher Jan 2019

Heating Rate And Temperature Effects On Pyrolysis Products From Live Wildland Fuels, Mohammad-Saeed Safdari, Elham Amini, David R. Weise, Thomas H. Fletcher

Faculty Publications

Wildland fire, which includes both planned (prescribed fire) and unplanned (wildfire) fires, is an important component of many ecosystems. During wildland fires, low heating rate pyrolysis (slow pyrolysis) occurs during preheating and/or smoldering of plant material. High heating rate pyrolysis (fast pyrolysis) exists in the flame region. Pyrolysis temperature and heating rate play important roles on the yields and the compositions of pyrolysis products. In this work, the effects of pyrolysis temperature and heating rate on the yields and the compositions of pyrolysis products from 14 plant species native to the forests of the southern United States are shown. The …


Review Of Carbonaceous Annealing Effects On O2 And Co2 Coal Reactivity, Troy Michael Holland, Thomas H. Fletcher, Osvalda Senneca Jan 2019

Review Of Carbonaceous Annealing Effects On O2 And Co2 Coal Reactivity, Troy Michael Holland, Thomas H. Fletcher, Osvalda Senneca

Faculty Publications

Coal is, and will remain for the foreseeable future, a critical energy production resource. Advanced models of coal conversion behavior in air and oxy-coal environments enhance the boiler operational efficiency and design optimization. Although coal conversion models have continuously improved over decades of research, not all aspects of coal particle heating and conversion have received equal treatment. Coal particle annealing is one aspect of the coal conversion process that is simultaneously highly sensitive to the conversion environment, exceptionally impactful on coal chemistry, and frequently neglected in coal models. However, the current body of literature has explored numerous aspects of coal …


Characterization Of Pyrolysis Products From Slow Pyrolysis Of Live And Dead Vegetation Native To The Southern United States, Elham Amini, Mohammad-Saeed Safdari, Jonathan Deyoung, David R. Weise, Thomas H. Fletcher Jan 2019

Characterization Of Pyrolysis Products From Slow Pyrolysis Of Live And Dead Vegetation Native To The Southern United States, Elham Amini, Mohammad-Saeed Safdari, Jonathan Deyoung, David R. Weise, Thomas H. Fletcher

Faculty Publications

Prescribed (i.e., controlled) burning is a common practice used in many vegetation types in the world to accomplish a wide range of land management objectives including wildfire risk reduction, wildlife habitat improvement, forest regeneration, and land clearing. To properly apply controlled fire and reduce unwanted fire behavior, an improved understanding of fundamental processes related to combustion of live and dead vegetation is needed. Since the combustion process starts with pyrolysis, there is a need for more data and better models of pyrolysis of live and dead fuels. In this study, slow pyrolysis experiments were carried out in a pyrolyzer apparatus …


Pyrolysis Kinetics Of Live And Dead Wildland Vegetation From The Southern United States, Elham Amini, Mohammad-Saeed Safdari, David R. Weise, Thomas H. Fletcher Jan 2019

Pyrolysis Kinetics Of Live And Dead Wildland Vegetation From The Southern United States, Elham Amini, Mohammad-Saeed Safdari, David R. Weise, Thomas H. Fletcher

Faculty Publications

The fundamental combustion behavior of live wildland vegetation is not fully understood. Since the combustion process during wildland fire starts with pyrolysis, there is a need for better understanding of pyrolysis to develop improved wildland fire models. The kinetics of pyrolysis of live and dead wildland vegetation has not been explored in detail. In this study, the pyrolysis kinetics were determined for 14 different plant species (live and dead) which are all native to the forests in the southern United States. Pyrolysis experiments were carried out in a Thermogravimetric analyzer (TGA) under inert conditions at 5 different heating rates ranged …


Modified Cpd Model For Coal Devolatilization At Underground Coal Thermal Treatment Conditions, Ding Wang, Thomas H. Fletcher, Swomitra Mohanty, Hoaquan Hu, Eric G. Eddings Jan 2019

Modified Cpd Model For Coal Devolatilization At Underground Coal Thermal Treatment Conditions, Ding Wang, Thomas H. Fletcher, Swomitra Mohanty, Hoaquan Hu, Eric G. Eddings

Faculty Publications

To study coal pyrolysis behavior at underground coal thermal treatment (UCTT) conditions, a modified CPD (M-CPD) model was developed and evaluated using two scales of experiments as well as two different coals, Utah Sufco and Illinois #6. Compared with the original CPD model, three major aspects were changed, including (1) rewriting the algorithm using MATLAB built-in functions; (2) developing a correlation method between coal elemental composition and the initial functional group population to calculate the effect of cross-linking on the lattice structure; and (3) using a two-activation energy approach for gas generation kinetics modeling. Results predicted by the M-CPD model …