Engineering Commons^™

Study Of The Minimum Spouting Velocity In A Draft Tube Conical Spouted Bed, Haritz Altzibar, G. Lopez, M. Olazar, J. Bilbao

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

A study has been carried out on the hydrodynamics of conical spouted beds with a non-porous draft-tube. A hydrodynamic correlation has been proposed for calculating the minimum spouting velocity as a function of dimensionless moduli that take into account geometric factors, particle characteristics and operating conditions. A statistical analysis of the data obtained following a design of experiments shows that the inlet diameter, particle diameter and the height of the entrainment zone are the parameter of greater influence on the minimum spouting velocity.

Dem-Cfd Modelling Of A Fluidized Bed Spray Granulator, Lennart Fries, Sergiy Antonyuk, Stefan Heinrich, Stefan Palzer

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Coupled DEM-CFD simulations have been performed to study the hydrodynamics of a Wurster granulator on the scale of individual particles. Based on extensive material tests, the collision behaviour of dry "Gamma"-Al2O3 particles is identified and incorporated into the model. The effect of process parameters like air flow rate and geometry details like the Wurster position is studied. Based on a physical description of the material properties, an effective tool for design and scale-up of a Wurster granulator is obtained.

Computational Study Of Layer Inversion In Two-Component Liquid-Fluidized Beds By Dem-Cfd, Alberto Di Renzo, Fernando Cello, Francesco Paolo Di Maio

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

In the present work the layer inversion phenomenon observed in experiments from the literature is reproduced via discrete element simulations, in which a novel drag force model valid for bi- and poly-disperse particle systems is used. The simulations serve both as validation of the drag model and as a tool to analyze the dynamics of the phenomenon. The comparison with published data is carried out in terms of bed height and component distributions as functions of the liquid velocity, showing very good agreement.

Zero-Dimensional Modeling Of Indirect Fluidized Bed Gasification, Anton Larsson, David Pallarés, Daniel Neves, Martin Seemann, Henrik Thunman

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Zero-dimensional models has been developed to investigate mass balance and fuel (biomass) Chalmers a 2-4MW indirect fluidized bed gasifier. The result from this work is that more than 95%(Mass) of the tars is converted in the gasifier and that the water gas shift reaction is far from equilibrium.

Dem Fluidization Of Smart Particles, Amit Suri, Masayuki Horio

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Numerical simulations using DEM for smart particles/bodies having a capability to induce a repulsive force on the particle based on the cognition were simulated. A particle-particle interaction type repulsive force was used to induce self fluidization and it was found that if the repulsive force is sufficiently high, fluidization of particles can be achieved.

Inside Photo, Sang Done Kim

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Inside Photo

Comparison Of Model Evaluation Methods To Develop A Comprehensive Watershed Simulation Model, Misgana K. Muleta

Civil and Environmental Engineering

Comprehensive environmental models such as the Soil and Water Assessment Tool (SWAT) are becoming an integral part of decision making processes for effective planning and management of natural resources. Before their use as decision making aid, however, models must be properly evaluated to improve their prediction accuracy and reduce the likelihood of making decisions that could lead to undesirable policy outcomes. Model evaluation refers to practices such as quality analysis of input data, sensitivity analysis, calibration and verification, and uncertainty analysis. Many methodologies have been developed for model evaluations over the years. One of the major limitations of the existing …

High Temperature Water Gas Shift Catalysts With Alumina, Morris D. Argyle, Tiberiu Popa, Guoqing Xu, Thomas F. Barton

Faculty Publications

Alumina (Al2O3) was added as a component of conventional iron oxide based high temperature water gas shift (WGS) catalysts. The catalysts contained Fe-Al-Cr-Cu-O and were synthesized by coprecipitation. A series of catalysts were prepared with 5 to 50 wt% Al2O3, 8 wt% Cr2O3, 4 wt% CuO, and the balance Fe2O3. One catalyst was prepared in which the chromia was replaced by alumina. All of the catalysts were compared to a reference WGS catalyst (88 wt% FeOX, 8 wt% Cr2O3, and 4 wt% CuO) with no alumina. The catalysts were characterized using temperature programmed reduction (TPR), surface area analysis using nitrogen …

Design And Analysis Of A Compliant Mechanism Spinal Implant, Eric M. Stratton

Theses and Dissertations

This thesis introduces and presents the modeling of a novel compliant spinal implant designed to reduce back pain and restore function to degenerate spinal disc tissues as well as provide a mechanical environment conducive to healing the tissues. The initial objectives for this device development and the focus of this work are modeling and validation of the force-deflection relationships and stress analysis. Modeling was done using the pseudo-rigid-body model to create a 3 degree of freedom mechanism for flexion-extension (forward-backward bending) and a 5 degree of freedom mechanism for lateral bending (side-to-side). These models were analyzed using the principle of …

Uniaxially-Driven Controlled Biaxial Testing Fixture, Fadi K. Abu-Farha, Marwan K. Khraisheh

Mechanical Engineering Faculty Patents

A uniaxially-driven controlled biaxial testing fixture includes a base, a first coupler mounted to the base, and a load input drive rack mounted for linear movement with respect to the base. A second coupler and a first specimen grip are both mounted to the load input drive rack. Second, third and fourth specimen grips are also mounted for linear movement with respect to the base. First, second and third drive mechanisms connect the load input drive rack to the second, third and fourth specimen grips. Together the four specimen grips are oriented to provide biaxial application of force to a …

Assembly Of Ordered Carbon Shells On Semconducting Nanomaterals, Eli Anguelova Sutter, Peter Werner Sutter

Department of Electrical and Computer Engineering: Faculty Publications

In some embodiments of the invention, encapsulated semiconducting nanomaterials are described. In certain embodiments the nanostructures described are semiconducting nanomaterials encapsulated with ordered carbon shells. In some aspects a method for producing encapsulated semiconducting nanomaterials is disclosed. In some embodiments applications of encapsulated semiconducting nanomaterials are described.

A One-Dimensional Finite-Difference Solver For Fully-Developed Pipe And Channel Flows, Doug F. Hunsaker

Utah Space Grant Consortium

An algorithm is developed to solve the fundamental flow cases of fully-developed turbulent flow in a pipe and in a channel. The algorithm uses second-order finite-difference approximations for nonuniform grid spacing and is developed in such a way as to easily facilitate the implementation of several two-equation, Reynolds-Averaged-Navier-Stokes turbulence models. Results are included for the Wilcox 1998 k-ω model.

An Algorithm And Methodology For Static Response Based Damage Detection In Structural Systems, Augusto Terlaje

All Theses and Dissertations (ETDs)

A damage detection algorithm and procedure is presented in this dissertation that utilizes static response data and Optimality Criterion optimization. Static displacement measurements are used as constraints in the damage detection algorithm that identifies potential areas of damage in structural systems. The research aims to improve upon the master's level research performed by the author. First, the robustness of the algorithm is improved by use of a least squares approximation for determining the Lagrange multipliers that are necessary for optimization. Second, an active parameter selection subroutine is used to improve the accuracy of damage detection in the presence of experimental …

An Ensemble-Based Computational Approach For Incremental Learning In Non-Stationary Environments Related To Schema- And Scaffolding-Based Human Learning, Ryan Elwell

Theses and Dissertations

The principal dilemma in a learning process, whether human or computer, is adapting to new information, especially in cases where this new information conflicts with what was previously learned. The design of computer models for incremental learning is an emerging topic for classification and prediction of large-scale data streams undergoing change in underlying class distributions (definitions) over time; yet currently, they often ignore significant foundational learning theory that has been developed in the domain of human learning. This shortfall leads to many deficiencies in the ability to organize existing knowledge and to retain relevant knowledge for long periods of time. …

Flight Control System For Small High-Performance Uavs, Jefferson Mcbride

Theses and Dissertations

This thesis documents a research project in which an autonomous flight control system (FCS) was designed to control and navigate small, high-speed, unmanned, jet-turbine powered fixed-wing aircraft. The FCS was designed to allow the aircraft to maintain controlled flight, and return to a home location, without any operator intervention. The flight control computer was built with an FPGA, using a Microblaze soft-core microprocessor running the uClinux operating system. The configurable FPGA computing platform allowed flexibility for interfacing quickly with a wide range of sensors and control modules. A commercial inertial measurement unit was used for aircraft state estimation, and the …

A Locally Adaptable Iterative Rx Detector, Yuri P. Taitano, Brian G. Geier, Kenneth W. Bauer

Faculty Publications

We present an unsupervised anomaly detection method for hyperspectral imagery (HSI) based on data characteristics inherit in HSI. A locally adaptive technique of iteratively refining the well-known RX detector (LAIRX) is developed. The technique is motivated by the need for better first- and second-order statistic estimation via avoidance of anomaly presence. Overall, experiments show favorable Receiver Operating Characteristic (ROC) curves when compared to a global anomaly detector based upon the Support Vector Data Description (SVDD) algorithm, the conventional RX detector, and decomposed versions of the LAIRX detector. Furthermore, the utilization of parallel and distributed processing allows fast processing time making …

Spatial Variability Of Levees As Measured Using The Cpt, Robb E.S. Moss, J. C. Hollenback, J. Ng

Civil and Environmental Engineering

The spatial variability of a soil deposit is something that is commonly discussed but difficult to quantify. The heterogeneity as a function of lateral distance can be critical to the design of long engineered structures such as highways, bridges, levees, and other lifelines. This paper presents a methodology for using CPT measurements to quantifying the spatial variability of cone tip resistance along a levee in the California Bay Delta. The results, presented in the form of a general relative variogram, identify the distance at which the maximum spatial variability is achieved for a given soil strata. This information helps define …

Game Theoretic Bidding Strategies For Auctions In Green Electricity Markets, Dipayan Ghosh

Honors Scholar Theses

Electricity markets in the United States presently employ an auction mechanism to determine the dispatch of power generation units. In this market design, generators submit bid prices to a regulation agency for review, and the regulator conducts an auction selection in such a way that satisfies electricity demand. Most regulators currently use an auction selection method that minimizes total offer costs ["bid cost minimization" (BCM)] to determine electric dispatch. However, recent literature has shown that this method may not minimize consumer payments, and it has been shown that an alternative selection method that directly minimizes total consumer payments ["payment cost …

The Impact Of Thermal Coupling On Catalyst Behavior In Wall-Coated Heat-Exchanger Microreactors, Gregory S. Honda

Honors Scholar Theses

This thesis presents a numerical study of reaction and diffusion phenomena in wall-coated heat-exchanger microreactors. Specifically, the interactions between an endothermic and exothermic catalyst layer separated by an impermeable wall is studied to understand the inherent behavior of the system. Two modeling approaches are presented, the first under the assumption of a constant thermal gradient and neglecting heat of reaction and the second considering both catalyst layers and reaction heat. Both studies found that thicker, more thermally insulating catalyst layers increase the effectiveness of the exothermic reaction by allowing for accumulation of reaction heat while thinner catalyst layers for the …

An Active Study Of A Roller Coaster Project In Asia., Robert Leamon Bridges

Electronic Theses and Dissertations

A roller coaster manufacturer became aware that improperly heat treated track couplings were sent to a construction site for assembly. Concerns were that suspect couplings might not meet the engineering specifications and could be vulnerable to sudden failure. A testing company in Oak Ridge, TN that specializes in in-situ and laboratory mechanical testing was contacted by the manufacturer for help in this endeavor. The construction company elected to enlist a local testing firm to perform field tests on the components instead of the company in Oak Ridge. The test methods used are incapable of providing quantitative results that could be …

A Safeguards Design Strategy For Domestic Nuclear Materials Processing Facilities., Jonathan Long

Electronic Theses and Dissertations

The outdated and oversized nuclear manufacturing complex within the United States requires its transformation into a smaller, safe, and secure enterprise. Health and safety risks, environmental concerns, and the end of the Cold War have all contributed to this necessity. The events of September 11, 2001, emphasized the protection requirements for nuclear materials within the U.S. as well as abroad.

Current Nuclear Safeguards regulations contain minimal prescriptive requirements relating to the design of new production facilities. Project management and engineering design guides require that design documents contain specific and measureable statements relating to systems requirements. The systems engineering process evaluates …

High Strength And Light-Weight Materials Inspired By The Exoskeleton Of Arthropods, Anette M. Karlsson

Mechanical Engineering Faculty Publications

This work investigates the multiscaled structure and the constitutive behavior of the exoskeleton of arthropods (Japanese beetle) along with the response of biomimicked structures. Image analysis (SEM and TEM) revealed three load-bearing regions comprised of chitin-protein fiber layers orientated parallel to the cuticle surface. The chitin fibers in the exocuticle and mesocuticle are organized in a helicoidal structure (layers stacked with a small rotational angle relative to their adjacent layers). The endocuticle has a distinct pseudo-orthogonal pattern, characterized by a thin transitional helicoidal region inserted between two orthogonal layers. Idealized mechanics based models showed that the pseudo-orthogonal structure redistributes the …

A Reactive Molecular Dynamics Simulation Of The Silica-Water Interface, Joseph C. Fogarty, Hasan Metin Aktulga, Ananth Y. Grama, Adri C. T. Van Duin, Sagar A. Pandit

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

We report our study of a silica-water interface using reactive molecular dynamics. This first-of-its-kind simulation achieves length and time scales required to investigate the detailed chemistry of the system. Our molecular dynamics approach is based on the ReaxFF force field of van Duin [J. Phys. Chem. A 107, 3803 (2003)]. The specific ReaxFF implementation (SERIALREAX) and force fields are first validated on structural properties of pure silica and water systems. Chemical reactions between reactive water and dangling bonds on a freshly cut silica surface are analyzed by studying changing chemical composition at the interface. In our simulations, reactions involving silanol …

Over The Air Programming On Imote2-Based Sensor Networks, Rashmdfi Parthasarathy, Nina Peterson, Wen Zhan Song, Ali Hurson, Behrooz A. Shirazi

Electrical and Computer Engineering Faculty Research & Creative Works

Some of the main challenges that Wireless Sensor Networks (WSNs) face are reliability, flexibility and security. When WSNs deployed in remote locations need to be reprogrammed, environmental conditions often make it impossible to physically retrieve them. over the Air Programming (OAP) plays an important role in achieving this task. Several platform dependent protocols have been developed for OAP including Deluge [4] and MOAP [3]. Due to the restrictions of these platform-dependent protocols, any modification to the hardware requires modifications to the underlying protocol. for example, using OAP for Imote2 sensors requires porting Deluge from an existing hardware. This paper reports …

2010 Spring Engr333 Poster 1, Eric Ledy, Rachel Jelgerhuis, Jasper Gondhi, Michael Gondhi, Steve Brink, John Mantel, Kyle Harvey, Jim Venleeuwen, Jacob Speelman, Mitch Brummel, Tyler Van Dongen, Nathan Van Heukelum, Lynette Hromada, Jen Meneely, Matthew Brouwer, Marc Eberlein, Steve Demaagd, Tim Opperwall, Andrew Dejong, Joel Love, Alex Boelkins, Amanda Hollinger, Betsy Huyser, Jason Dornbos, Jason Handlogten, Justin Karsten, Matt Milan

ENGR 333

Calvin is developing plans for a new data center to provide business continuity and quick recovery in the event of a disaster. The new data center will not replace the existing data center; rather, it will provide redundancy for the operations of the campus. This new data center will be placed in the Spoelhof Complex. Because of the energy demands of data centers, there is a worldwide push for energy efficiency. So-called “green data centers” provide the same functionality as a normal data center with reduced energy usage and reduced energy costs. Calvin, like most organizations, must weigh the long-term …

2010 Spring Engr333 Poster 2, Eric Ledy, Rachel Jelgerhuis, Jasper Gondhi, Michael Gondhi, Steve Brink, John Mantel, Kyle Harvey, Jim Vanleeuwen, Jacob Speelman, Mitch Brummel, Tyler Van Dongen, Nathan Van Heukelum, Lynette Hromada, Jen Meneely, Matthew Brouwer, Marc Eberlein, Steve Demaagd, Tim Opperwall, Andrew Dejong, Joel Love, Alex Boelkins, Amanda Hollinger, Betsy Huyser, Jason Dornbos, Jason Handlogten, Justin Karsten, Matt Milan

ENGR 333

The new redundant data center requires that Network Operations Center personnel are able to monitor certain conditions within the data center for the safety of the server equipment. Server equipment will fail if it gets too hot or if the surrounding environment becomes too humid, therefore the baseline instrumentation design must monitor both temperature and humidity in the data center. The system must also be capable of remotely alerting NOC personnel when there is a problem.

Probabilistic Matching Pursuit For Compressive Sensing, Atul Divekar, Okan K. Ersoy

Department of Electrical and Computer Engineering Technical Reports

Compressive sensing investigates the recovery of a signal that can be sparsely represented in an orthonormal basis or overcomplete dictionary given a small number of linear combinations of the signal. We present a novel matching pursuit algorithm that uses the measurements to probabilistically select a subset of bases that is likely to contain the true bases constituting the signal. The algorithm is successful in recovering the original signal in cases where deterministic matching pursuit algorithms fail. We also show that exact recovery is possible when the number of nonzero coefficients is upto one less than the number of measurements. This …

Simulation Of A Tubular Solid Oxide Fuel Cell Stack Operating On Biomass Syngas Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

A tubular solid oxide fuel cell (SOFC) stack was modelled and its operation on biomass syn-gas was investigated. The objective of this work was to develop a computer simulation model of a biomass gasification-SOFC (BG-SOFC) system capable of predicting performance under various operating conditions and using diverse fuels. The stack was modelled using Aspen Plus and considers ohmic, activation and concentration losses. It was validated against published data for operation on natural gas. Operating parameters such as fuel and air utilisation factor U_f and U_a, current density j and steam to carbon ratio STCR were varied and …

Novel Wavelength Diversity Technique For High-Speed Atmospheric Turbulence Compensation, William W. Arrasmith, Sean F. Sullivan

Electrical Engineering and Computer Science Faculty Publications

The defense, intelligence, and homeland security communities are driving a need for software dominant, real-time or near-real time atmospheric turbulence compensated imagery. The development of parallel processing capabilities are finding application in diverse areas including image processing, target tracking, pattern recognition, and image fusion to name a few. A novel approach to the computationally intensive case of software dominant optical and near infrared imaging through atmospheric turbulence is addressed in this paper. Previously, the somewhat conventional wavelength diversity method has been used to compensate for atmospheric turbulence with great success. We apply a new correlation based approach to the wavelength …

Cad Simulated And Experimental Beam Profile Analysis Of Single-Mode Tapered Fibers For Optical Bandwidth Enhancement Applications, Syed H. Murshid, Raka Biswas, Abhijit Chakravarty

Electrical Engineering and Computer Science Faculty Publications

Most developments in data transfer techniques are incremental by nature and the goal of increasing total capacity in optical communications and networking requires new concepts for basic transmission media. The transmission data rates can only be enhanced by introducing new modulation and multiplexing techniques. In this paper different single mode tapered fiber waveguides are used to design a Spatial Multiplexer Unit (SMU) for a novel optical fiber multiplexing technique called the Spatial Domain Multiplexing (SDM) that allows co-propagation of two or more channels of exactly same wavelength without interfering with each other. This paper also presents a CAD model for …