Engineering Commons^™

Simulation Of Vertical Axis Wind Turbines With Variable Pitch Foils, L. Damon Woods, John F. Gardner, Kurt S. Myers

Mechanical and Biomedical Engineering Faculty Publications and Presentations

A dynamic computer model of a turbine was developed in MATLAB in order to study the behavior of vertical axis wind turbines (VAWTs) with variable pitch (articulating) foils. The simulation results corroborated the findings of several empirical studies on VAWTs. The model was used to analyze theories of pitch articulation and to inform the discussion on turbine design. Simulations of various models showed that pitch articulation allowed Darrieus-style vertical axis wind turbines to start from rest. Once in motion, the rotor was found to accelerate rapidly to very high rotational velocities. The simulations revealed a plateau region of high efficiency …

Technical Subtopic 2.1: Modeling Variable Refrigerant Flow Heat Pump And Heat Recovery Equipment In Energyplus, Florida Solar Energy Center, Richard Raustad

FSEC Energy Research Center®

The University of Central Florida/Florida Solar Energy Center, in cooperation with the Electric Power Research Institute and several variable-refrigerant-flow air conditioning (VRF AC) manufacturers, provided a detailed computer model for a VRF AC system in the United States Department of Energy's (U.S. DOE) EnergyPlus' building energy simulation tool. No other simulation tool currently has the capability to accurately model this state-of-the-art VRF heating, ventilating, and air conditioning (HVAC) equipment. Detailed laboratory testing and field demonstrations were performed to measure equipment performance and compare this performance with that predicted by the use of this new model through computer simulation.

This project …

Computational Modeling And Experimental Study On Optical Microresonators Using Optimal Spherical Structure For Chemical Sensing, Hanzheng Wang, Lei Yuan, Jie Huang, Xinwei Lan, Cheol-Woon Kim, Lan Jiang, Hai Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

Chemical sensors based on optical microresonators have been demonstrated highly sensitive by monitoring the refractive index (RI) changes in the surrounding area near the resonator surface. In an optical resonator, the Whispering Gallery Modes (WGMs) with high quality (Q) factor supported by the spherical symmetric structure interacts with the contiguous background through evanescent field. Highly sensitive detection can be realized because of the long lifetime of the photons. The computational models of solid glass microspheres and hollow glass spheres with porous wall (PW-HGM) were established. These two types of microresonators were studied through simulations. The PWHGM resonator was proved as …

Aspen Plus Simulation Of Biomass Gasification In A Steam Blown Dual Fluidised Bed, Wayne Doherty, Anthony Reynolds, David Kennedy

Book/Book Chapters

The efficient utilisation of biomass resources is of utmost importance. Biomass gasification offers much higher efficiencies than combustion. Gasification is a process in which a fuel is converted to a combustible gas (syngas). A dual fluidised bed gasifier known as the fast internally circulating fluidised bed (FICFB) was selected. It has been demonstrated at industrial scale and data is readily available for model validation. An Aspen Plus model was developed to simulate the FICFB gasifier. The model is based on Gibbs free energy minimisation and the restricted equilibrium method was used to calibrate it. The model has been validated and …

Dynamics And Dislodgment From Pore Constrictions Of A Trapped Nonwetting Droplet Stimulated By Seismic Waves, Wen Deng, M. Bayani Cardenas

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Seismic waves affect fluid flow and transport processes in porous media. Therefore, quantitative understanding of the role of seismic waves in subsurface hydrodynamics is important for the development of practical applications and prediction of natural phenomena. We present a theoretical fluid dynamics model to describe how low-frequency elastic waves mobilize isolated droplets trapped in pores by capillary resistance. The ability of the theoretical model to predict the critical mobilization amplitudes (A_c) and the displacement dynamics of the nonwetting droplet are validated against computational fluid dynamics (CFD) simulations. Our theory has the advantage of rapid calculation of A_{c …}

A Simulation Approach To Airline Cost Benefit Analysis, Massoud Bazargan, David Lange, Luyen Tran, Zhiyuan Zhou

Management, Marketing and Operations - Daytona Beach

In this paper we conduct a cost benefit analyses using simulation for an Airline. This study pertains to using Towbarless Towing Vehicles (commonly referred to as supertugs) to transport aircraft to and from the terminal to airline’s maintenance hangar facility at their hub. This study attempts to investigate the possibility of reducing costs through saving jet fuel by adopting supertugs and identify if their high purchasing costs are justified. This study adopts simulation to analyze the annual savings by studying the numbers needed, as well as the utilization and operation cost for these supertugs. The results are very encouraging, enabling …

The Impact Of Various Steel Stud Wall Frame Components On Energy Efficiency Analysis – Case Study, Aiyin Jiang

Construction Management Faculty Research and Scholarship

Steel stud framing is an excellent alternative to wood stud framing in residential construction. Steel framing is structurally sound, sustainable, and resistant to mold and insect infestation. However, the use of steel framing in the residential market remains low, due in large part to concerns on the thermal performance of steel. Over the past several years, engineers and constructors have increased the thermal resistance of steel stud walls through various wall assembly improvements, the impact of these components on energy efficiency is unclear. This study applies computer software to simulate the performance of various steel stud wall system assemblies. This …

Optimization Of Mixing In A Simulated Biomass Bed Reactor With A Center Feeding Tube, Michael T. Blatnik

Masters Theses 1911 - February 2014

Producing gasoline-type fuels from lignocellulosic biomass has two advantages over producing alcohol-type fuels from plant sugars: gasoline has superior fuel characteristics and plant lignin/cellulose does not compete with human food supplies. A promising technology for converting lignocellulose to fuel is catalytic fast pyrolysis (CFP). The process involves injecting finely ground biomass into a fluidized bed reactor (FBR) at high temperatures, which reduce the biomass to gases that react inside the catalyst particles. This entails complex hydrodynamics to efficiently mix a stream of biomass into a catalyst bed that is fluidized by a separate stream of inert gas. Understanding the hydrodynamics …

Fault Tree Analysis For Safety/Security Verification In Aviation Software, Andrew J. Kornecki, Mingye Liu

Department of Electrical Engineering and Computer Science - Daytona Beach

The Next Generation Air Traffic Management system (NextGen) is a blueprint of the future National Airspace System. Supporting NextGen is a nation-wide Aviation Simulation Network (ASN), which allows integration of a variety of real-time simulations to facilitate development and validation of the NextGen software by simulating a wide range of operational scenarios. The ASN system is an environment, including both simulated and human-in-the-loop real-life components (pilots and air traffic controllers).Real Time Distributed Simulation (RTDS) developed at Embry-Riddle Aeronautical University, a suite of applications providing low and medium fidelity en-route simulation capabilities, is one of the simulations contributing to the ASN. …

Development Of A Master Of Software Assurance Reference Curriculum, Andrew J. Kornecki, James Mcdonald, Julia H. Allen, Mark Ardis, Nancy Mead, Richard Linger, Thomas B. Hilburn

Department of Electrical Engineering and Computer Science - Daytona Beach

The Next Generation Air Traffic Management system (NextGen) is a blueprint of the future National Airspace System. Supporting NextGen is a nation-wide Aviation Simulation Network (ASN), which allows integration of a variety of real-time simulations to facilitate development and validation of the NextGen software by simulating a wide range of operational scenarios. The ASN system is an environment, including both simulated and human-in-the-loop real-life components (pilots and air traffic controllers).Real Time Distributed Simulation (RTDS) developed at Embry-Riddle Aeronautical University, a suite of applications providing low and medium fidelity en-route simulation capabilities, is one of the simulations contributing to the ASN. …

A Molecular Dynamics Simulation Of Fracture In Nanocrystalline Copper, Linqing Pei, Cheng Lu, Kiet Tieu, Hongtao Zhu, Xing Zhao, Kuiyu Cheng, Liang Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

A large-scale molecular dynamics simulation was used to investigate the propagation of cracks in three dimensional samples of nanocrystalline copper, with average grain sizes ranging from 5.34 to 14.8 nm and temperatures ranging from 1K to 500 K. It was shown that intragranular fracture can proceed inside the grain at low temperature, and plastic deformation around the tip of the crack is accommodated by dislocation nucleation/emission; indeed, both fully extended dislocation and deformation twinning were visible around the tip of the crack during fracture. In addition, due to a higher concentration of stress in front of the crack at a …

Impact Of Patient Rotational Errors On Target And Critical Structure Dose In Imrt: A 3d Simulation Study, S Arumugam, A Xing, P Vial, A Scotti, R Stirton, G Goozee, Lois Holloway

Faculty of Engineering and Information Sciences - Papers: Part A

The impact of 3D rotational errors in patient positioning on dose delivered target volumes and critical structures in IMRT was studied. Patient rotational errors ranging from -30 to +30 was introduced to IMRT treatment plans of pelvis, head and neck and brain treatment sites and the impact of rotational error on DVH metrics was assessed. The magnitude of impact of rotational error on the error in dose delivered to the target volume and critical structures depends on the location of the structures from plan isocentre. In studied plans, a maximum percentage difference of up to -9.8(1s=13.4) % in D95 to …

Effect Of Particle Properties On The Discrete Element Simulation Of Wall Friction, Andrew Grima, Peter Wypych

Faculty of Engineering and Information Sciences - Papers: Part A

Modelling the interaction between particles and boundaries is of great interest and importance in many Discrete Element Method (DEM) applications where boundary failure conditions dictate the flow behaviour and velocity gradients of a bulk material. Bulk wall friction angles in DEM models are dependent on the mechanical properties of the particles and boundary material as well as the constraints of the contact models used, especially the tangential and rolling torque components. This paper examines the parameters determined from the calibration inclination test by conducting direct wall shear tests to validate the accuracy of the calibration parameters and the sensitivity of …

The Simulation Of Particle Flow Mechanisms In Dustiness Testers, Sathaphon Wangchai, David B. Hastie, Peter W. Wypych

Faculty of Engineering and Information Sciences - Papers: Part A

Dust generation is a common result of many bulk handling and mining applications and has potentially serious consequences to the surrounding environment as well as workers and nearby community. Companies need to know how much and what type of dust is being generated so they can find ways to reduce this dust. Dustiness testers can be used for this purpose. This paper investigates the rotating drum testers used for dustiness testing of bulk solids and the subsequent discrete element method (DEM) simulation of the particle mechanisms. Preliminary comparisons of the rotating drum designs were undertaken using particle/bulk parameters of a …

A P2p Computing System For Overlay Networks, Grzegorz Chmaj, Krzysztof Walkowiak

Electrical & Computer Engineering Faculty Research

A distributed computing system is able to perform data computation and distribution of results at the same time. The input task is divided into blocks, which are then sent to system participants that offer their resources in order to perform calculations. Next, a partial result is sent back by the participants to the task manager (usually one central node). In the case when system participants want to get the final result, the central node may become overloaded, especially if many nodes request the result at the same time. In this paper we propose a novel distributed computation system, which does …

Collective Librations Of Water Molecules In The Crystal Lattice Of Rubidium Bromide: Experiment And Simulation, L M. Lepodise, J Horvat, Roger A. Lewis

Australian Institute for Innovative Materials - Papers

Terahertz spectroscopy of RbBr reveals four prominent absorption lines at room temperature and a further 15 lines at 10 K. Via density-functional-theory (DFT) numerical modelling using the PBE0 hybrid GGA functional, all the absorptions are identified as correlated librations of water molecules in the RbBr lattice. Each libration mode is a combination of rocking, wagging and twisting motions of the water molecules. The number of libration lines and numerical modelling show that the C2v symmetry of water in RbBr is broken. Our modelling shows that the distribution of libration amplitudes and phases for different water molecules in the RbBr unit …

Simulation Of Defects In Micro-Deep Drawing Of An Aluminium Alloy Foil, Syamsul Hadi, Hai-Liang Yu, Kiet Tieu, Cheng Lu

Faculty of Engineering and Information Sciences - Papers: Part A

Micro-forming refers to the application of conventional forming processes to manufacture products from ultra-thin sheet materials. While attempting to meet the increasing demand for cost-effective manufacturing of micro-formed components, it is very important to reduce the defects in the products. In this paper, we report a number of Finite Element (FE) simulations of the micro-deep drawing process with various sample thicknesses and eccentric distances. The simulations indicated that when the sample thickness is nearly equal to the gap between the plunger and the die, the sample is likely to develop fractures at the bottom corner. When the sample thickness is …

Microsimulation Evaluation Of Eurocode Load Model For American Long-Span Bridges, Bernard Enright, Colm Carey, Colin Caprani

Articles

The ability to accurately predict traffic loading is essential for cost-effective bridge maintenance and repair programs. The traffic load model currently used in the United States for the design of long-span bridges was developed over three decades ago. In the meantime vehicle characteristics and traffic patterns have changed. The Eurocode for traffic loading is more recent, but was calibrated only for bridges up to 200 m long. In this work, Weigh-In-Motion traffic records from 11 different sites across Alabama are used to establish congested traffic loading. Traffic microsimulation is used to generate the congestion, based on the real traffic data. …