Mechanical Engineering Commons^™

Application Of Variation Of Parameters To Solve Nonlinear Multimode Heat Transfer Problems, Travis J. Moore

Theses and Dissertations

The objective of this work is to apply the method of variation of parameters to various direct and inverse nonlinear, multimode heat transfer problems. An overview of the general method of variation of parameters is presented and applied to a simple example problem. The method is then used to obtain solutions to three specific extended surface heat transfer problems: 1. a radiating annular fin, 2. convective and radiative exchange between the surface of a continuously moving strip and its surroundings, and 3. convection from a fin with temperature-dependent thermal conductivity and variable cross-sectional area. The results for each of these …

Evaluation Of Heat Recovery Options For Improved Energy Efficiency Of A Manufacturing Facility, Allison Chouinard

Master's Theses (2009 -)

Nationwide process heating in the manufacturing sector accounts for 7,815 trillion BTU of energy use annually; this is roughly one-third of the sector's total energy consumption [Energetics Incorporated, 2014]. The U.S. Department of Energy estimates that seventy percent of process heating is fueled by the onsite burning of fossil fuels [Energetics Incorporated, 2014]. These fuel-fired process heating applications are prime opportunities for heat recovery projects capable of saving energy and, consequently, reducing operating costs. This thesis evaluates different methods for heat recovery in the Milwaukee manufacturing facility of STRATTEC Security Corporation. As a basis for this work, the overall energy …

Within-Socket Myoelectric Prediction Of Continuous Ankle Kinematics For Control Of A Powered Transtibial Prosthesis, Samuel Farmer, M. Barbara Silver-Thorn, Philip A. Voglewede, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Objective. Powered robotic prostheses create a need for natural-feeling user interfaces and robust control schemes. Here, we examined the ability of a nonlinear autoregressive model to continuously map the kinematics of a transtibial prosthesis and electromyographic (EMG) activity recorded within socket to the future estimates of the prosthetic ankle angle in three transtibial amputees. Approach. Model performance was examined across subjects during level treadmill ambulation as a function of the size of the EMG sampling window and the temporal 'prediction' interval between the EMG/kinematic input and the model's estimate of future ankle angle to characterize the trade-off between model error, …

Stress Amplification During Development Of The Tendon-To-Bone Attachment, Y. Liu, A. G. Schwartz, Victor Birman, S. Thomopoulos, G. M. Genin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Passive Phase Separation Of Microgravity Bubbly Flows Using Conduit Geometry, Ryan M. Jenson, Andrew Paul Wollman, Mark M. Weislogel, Lauren Sharp, Robert Green, Peter J. Canfield, Jörg Klatte, Michael E. Dreyer

Mechanical and Materials Engineering Faculty Publications and Presentations

The ability to separate liquid and gas phases in the absence of a gravitational acceleration has proven a challenge to engineers since the inception of space exploration. Due to our singular experience with terrestrial systems, artificial body forces are often imparted in multiphase fluid systems aboard spacecraft to reproduce the buoyancy effect. This approach tends to be inefficient, adding complexity, resources, and failure modes. Ever present in multiphase phenomena, the forces of surface tension can be exploited to aid passive phase separations where performance characteristics are determined solely by geometric design and system wettability. Said systems may be readily designed …

Electric Vehicle Life Cycle Cost Assessment, Florida Solar Energy Center, Richard Raustad

FSEC Energy Research Center®

The Electric Vehicle Transportation Center (EVTC) has developed a life cycle cost (LCC) model to include all reasonable costs associated with vehicle ownership over a 5, 10, 15, or 20-year period. The EVTC LCC model compares ownership costs of conventional vehicles to plug-in hybrid and battery electric vehicles. Internal combustion engines using gasoline, ethanol, or diesel are considered. The analysis includes costs for tires, insurance and maintenance, federal incentives, state tax, dealership fee, and financed interest payments. Traction battery replacement costs are difficult to ascertain yet are included to investigate their impact on overall life cycle costs. Economic factors used …

Control Of The Diffracted Response Of A Metallic Wire Array With Double Period: Experimental Demonstration, Nicholas A. Roberts, D. C. Skigin, J. D. Fowlkes, L. B. Scaffardi, D. C. Schinca, M. Lester

Mechanical and Aerospace Engineering Faculty Publications

In recent papers, it has been theoretically shown that by using dual-period wire gratings, it is possible to control the relative efficiencies of the diffracted orders, regardless of the wires’ material, incident polarization and wavelength. In this Letter, we experimentally demonstrate, for the first time, that by appropriately choosing the geometrical parameters of a nanometric periodic structure, it is possible to control the optical response in the visible range. We show examples of nanostructures designed to cancel out or to intensify a particular diffraction order. Such nanostructures allow a broad control over the directionality and the intensity of the diffracted …

An Analysis Of Fuel Cell Vehicle Models By Major Automakers, Florida Solar Energy Center, Nan Qin

FSEC Energy Research Center®

Fuel cell electric vehicles (FCEVs) use hydrogen as fuel and exhaust only water. They provide driving ranges and fueling times comparable to gasoline vehicles. Despite the advantages, FCEVs have been in and out of spot light of the auto industry for the past several decades. The information on the development of fuel cell vehicles by major automakers is disparate. This report systematically examined the technical developments of FCEVs since the introduction of the first lab-based fuel cell vehicle in 1966. It included an overview of 117 FCEV models from 31 automakers. It should help the stakeholders to gain an insight …

Design Of A Frequency-Selective Surface Strain Sensor, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Frequency Selective Surfaces (FSS) have long been used in the RF/microwave community to control radar cross-section. The scattering parameters of the FSS form a signature which is a function of the frequency, element size and spacing, as well as the local electromagnetic environment. This paper considers a FSS as a strain sensor on the surface of a structural element. By interrogating the FSS with a series of polarized far-field measurements in a bistatic configuration the biaxial plane strain, including shear, can be resolved.

Convective Heat Transfer With And Without Film Cooling In High Temperature, Fuel Rich And Lean Environments, Nathan J. Greiner

Theses and Dissertations

Modern turbine engines require high turbine inlet temperatures and pressures to maximize thermal efficiency. Increasing the turbine inlet temperature drives higher heat loads on the turbine surfaces. In addition, increasing pressure ratio increases the turbine coolant temperature such that the ability to remove heat decreases. As a result, highly effective external film cooling is required to reduce the heat transfer to turbine surfaces. Testing of film cooling on engine hardware at engine temperatures and pressures can be exceedingly difficult and expensive. Thus, modern studies of film cooling are often performed at near ambient conditions. However, these studies are missing an …

Long-Lasting Effect Of Initial Configuration In Gravitational Spreading Of Material Fronts, ‪Nadim Zgheib, Thomas Bonometti, S. Balachandar

Mechanical Engineering Faculty Publications

We present the results from laboratory experiments and fully resolved simulations pertaining to finite-release turbulent density flows with a non-axisymmetric initial shape. First, we demonstrate that the effects of the initial shape influence the current’s evolution well into the long-time phase which would corresponds to the inertial self-similar phase in the case of planar or axisymmetric configurations. Then, we identify the physical mechanisms responsible for this dependence and propose a new model capable of capturing the dynamics of such releases. Finally, we show that this dependence on the initial configuration is robust for various types of gravity currents over a …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Dr. Soloiu wins Award for Excellence in Research

• Dr. Mitra wins Award for Excellence in Service

A Collagen‐Glycosaminoglycan‐Fibrin Scaffold For Heart Valve Tissue Engineering Applications, Claire Brougham, Stefan Jockenhoevel, Thomas Flanagan, Fergal O'Brien

Conference Papers

The field of heart valve biology and tissue engineering a heart valve continue to expand. The presentatio ns at this meeting reflect the advances made in both areas due to the multi-disciplinary approach taken by many laboratories.

A Control-Chart Based Method For Solder Joint Crack Detection, Jianbiao Pan

Industrial and Manufacturing Engineering

Many researchers have used different failure criteria in published solder joint reliability studies. Since the reported timeto-failure would be different if different failure criteria were used, it would be difficult to compare the reported reliability life of solder joints from one study to another. The purpose of this study is to evaluate the effect of failure criteria on the reported thermal fatigue life and determine which failure criterion could detect failure sooner. First, the application of the control-chart-based method in a thermal cycling reliability study is described. The reported time-to-failure data were then compared based on four different failure criteria: …

Serious Fun: Using Toys To Demonstrate Fluid Mechanics Principles, Camilla M. Saviz, Said Shakerin

All Faculty Articles - School of Engineering and Computer Science

Many students have owned or seen fluids toys in which two immiscible fluids within a closed container can be tilted to generate waves. These types of inexpensive and readily available toys are fun to play with, but they are also useful for provoking student learning about fluid properties or complex fluid behavior, including drop formation and coalescence. Including these toys in a class or lab with a companion exercise allows students to use observation and inductive reasoning to infer principles-all while having fun.

Agricultural Industry Advanced Vehicle Technology: Benchmark Study For Reduction In Petroleum Use, Roger M. Hoy, Rodney Rohrer, Adam Liska, Joe D. Luck, Loren Isom, Deepak R. Keshwani

Adam Liska Papers

Diesel use on farms in the United States has remained relatively constant since 1985, decreasing slightly in 2009, which may be attributed to price increases and the economic recession. During this time, the United States’ harvested area also has remained relatively constant at roughly 300 million acres. In 2010, farm diesel use was 5.4% of the total United States diesel use. Crops accounting for an estimated 65% of United States farm diesel use include corn, soybean, wheat, hay, and alfalfa, respectively, based on harvested crop area and a recent analysis of estimated fuel use by crop. Diesel use in these …

The Effects Of Electrode Size And Configuration On Plasma Actuator Thrust And Effectiveness At Low Pressure, Paul Daniel Friz, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

How Sensitive Is The Deltoid Moment Arm To Joint Center Changes With Rtsa?, David Walker, Allison Kinney, Aimee Struk, Benjamin J. Fregly, Thomas Wright, Scott Banks

Mechanical and Aerospace Engineering Faculty Publications

The goal of this study was to assess the sensitivity of the deltoid muscle moment arms as a function of joint configuration for an existing RTSA subject. High variations were found for all three deltoid components. Variation over the entire abduction arc was greatest in the anterior and lateral deltoid, while the posterior deltoid moment arm was mostly sensitive to joint center changes early in the abduction arc. Moment arm changes of 10-16mm represent a significant amount of the total deltoid moment arm. This means there is an opportunity to dramatically change the deltoid moments arms through surgical placement of …

Deltoid Moment Arms During Abduction: A Subject-Specific Musculoskeletal Modeling Study In Healthy Shoulders And Shoulders With Rtsa, David Walker, Allison Kinney, Aimee Struk, Benjamin J. Fregly, Thomas Wright, Scott Banks

Mechanical and Aerospace Engineering Faculty Publications

Reverse total shoulder arthroplasty (RTSA) is increasingly used in the United States since approval by the FDA in 2003. RTSA relieves pain and restores mobility in arthritic rotator cuff deficient shoulders. Though many advantages of RTSA have been demonstrated, there still are a variety of complications (implant loosening, shoulder impingement, infection, frozen shoulder) making apparent much still is to be learned how RTSA modifies normal shoulder function. The goal of this study was to assess how RTSA affects deltoid muscle moment generating capacity post-surgery using a subjectspecific computational model driven by in vivo kinematic data.

A Novel Approach To Estimation Of Patient-Specific Muscle Strength, David Walker, Allison Kinney, Benjamin J. Fregly, Thomas Wright, Scott Banks

Mechanical and Aerospace Engineering Faculty Publications

Current modeling techniques have been used to model the Reverse Total Shoulder Arthroplasty (RTSA) to account for the geometric changes implemented after RTSA. Though these models have provided insight into the effects of geometric changes from RTSA these is still a limitation of understanding muscle function after RTSA on a patient-specific basis. The goal of this study sought to overcome this limitation by developing an approach to calibrate patient-specific muscle strength for an RTSA subject.

Piv Measurements Of Turbulent Flow In A Rectangular Channel Over Superhydrophobic Surfaces With Riblets, Richard Mark Perkins

Theses and Dissertations

In this thesis I investigate characteristics of turbulent flow in a channel where one of the walls has riblets, superhydrophobic microribs, or a hybrid surface with traditional riblets built on a superhydrophobic microrib surface. PIV measurements are used to find the velocity profile, the turbulent statistics, and shear stress profile in the rectangular channel with one wall having a structured test surface. Both riblets and superhydrophobic surfaces can each provide a reduction in the wall shear stress in a turbulent channel flow. Characterizing the features of the flow using particle image velocimetry (PIV) is the focus of this research. Superhydrophobicity …

Vibration Based Planetary Gear Analysis And Damage Detection, Rene Sawatzky

Master's Theses

With this thesis the research at the engineering department is continued, based on previous thesis projects. These projects were considering the possibility of simulation gears with rigid bodies. After researches with different emphasizes on the rigid body simulation, the gained knowledge showed limitations of the rigid body model. Gear failures are very diverse and the actual simulation technique could not represent all necessary failure modes that can occur. That led to this thesis as a research project to find a way to detect and analyze the failure modes that cannot be considered with the current rigid body approach. With the …

Theoretical Prediction Of Experimental Jump And Pull-In Dynamics In A Mems Sensor, Laura Ruzziconi, Abdallah H. Ramini, Mohammad I. Younis, Stefano Lenci

Mechanical Engineering Faculty Scholarship

The present research study deals with an electrically actuated MEMS device. An experimental investigation is performed, via frequency sweeps in a neighbourhood of the first natural frequency. Resonant behavior is explored, with special attention devoted to jump and pull-in dynamics. A theoretical single degree-of-freedom spring-mass model is derived. Classical numerical simulations are observed to properly predict the main nonlinear features. Nevertheless, some discrepancies arise, which are particularly visible in the resonant branch. They mainly concern the practical range of existence of each attractor and the final outcome after its disappearance. These differences are likely due to disturbances, which are unavoidable …

Me-Em Enewsbrief, September 2014, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

A Method To Develop Neck Injury Criteria To Aid Design And Test Of Escape Systems Incorporating Helmet Mounted Displays, Jeffrey C. Parr

Theses and Dissertations

HMDs are becoming common human-machine interface equipment in manned military flight, but introducing this equipment into the overall aircraft escape system poses new and significant system design, development, and test concerns. Although HMDs add capabilities, which improve operator performance, the increased capability is often accompanied by increased head supported mass. The increased mass can amplify the risk of pilot neck injury during ejection when compared to lighter legacy helmets. Currently no adequate USAF neck injury criteria exist to effectively guide the requirements, design, and test of escape systems for pilots with HMDs. This research effort presents a novel method to …

Extended Formation Flight At Transonic Speeds, Andrew Ning, Ilan Kroo, Michael Aftosmis, Marian Nemec, James Kless

Faculty Publications

Aircraft flown in formation can realize significant reductions in induced drag by flying in regions of wake upwash. However, most transports fly at transonic speeds where the impact of compressibility on formation flight is not well understood. This study utilizes an Euler solver to analyze the inviscid aerodynamic forces and moments of transonic wing/body configurations flying in a two-aircraft formation. Formations with large streamwise separation distances (10-50 wingspans) are considered.

This work indicates that compressibility-related drag penalties in formation flight may be eliminated by slowing 2-3% below the nominal out-of-formation cruise Mach number (either at fixed lift coefficient or fixed …

Sustainable Business Development: An Irish Perspective, Tony Kealy

Conference Papers

This research investigates the current status of sustainable business development practises in Ireland using qualitative analysis on data obtained from semi-structured interviews. The thirteen interviewees were chosen to represent a wide spectrum of influential organisations in Irish society and included private businesses, charity organisations, faith-based organisations, farmer associations, and government representatives. Analysis of the findings confirmed that the three well established key elements that must be considered if businesses are to be developed in a sustainable way, namely Profit, People, and Planet are still valid. However, this research also found that there were other elements important for developing sustainable business. …

A Simple Solution Method For The Blade Element Momentum Equations With Guaranteed Convergence, Andrew Ning

Faculty Publications

The blade element momentum equations, though conceptually simple, can be challenging to solve reliably and efficiently with high precision. These requirements are particularly important for efficient rotor blade optimization that utilizes gradient-based algorithms. Many solution approaches exist for numerically converging the axial and tangential induction factors. These methods all generally suffer from a lack of robustness in some regions of the rotor blade design space, or require significantly increased complexity to promote convergence. The approach described here allows for the blade element momentum equations to be parameterized by one variable: the local inflow angle. This reduction is mathematically equivalent, but …

Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

A computational framework was implemented and validated to better understand the hypertensive artery remodeling in both geometric dimensions and material properties. Integrating the stress-modulated remodeling equations into commercial finite element codes allows a better control and visualization of local mechanical parameters. Both arterial thickening and stiffening effects were captured and visualized. An adaptive material remodeling strategy combined with the element birth and death techniques for the geometrical growth were implemented. The numerically predicted remodeling results in terms of the wall thickness, inner diameter, and the ratio of elastin to collagen content of the artery were compared with and fine-tuned by …

Experimental Characterization Of Optical Nonlocalities In Metal-Dielectric Multilayer Metamaterials, L. Sun, F. Cheng, C. J. Mathai, S. Gangopadhyay, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.