Mechanical Engineering Commons^™

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.

Achieving Challenge Home In Affordable Housing In The Hot-Humid Climate, Florida Solar Energy Center, David Beal

FSEC Energy Research Center®

The Building America Partnership for Improved Residential Construction (BA-PIRC) worked with two affordable housing builders who pursued and achieved CH certification. Both builders needed very few changes to reach CH; however, both were already certifying homes under the ENERGY STAR® for Homes Standard v.3.1. Habitat for Humanity affiliates’ mortgage terms are 0% interest over a 30-year mortgage to qualified buyers. To improve relevance of the study to the general homebuilding community, the cost-effectiveness calculations herein are based on a code-minimum reference rather than the builders’ standard practice (ENERGY STAR), and projected first year cash flow is provided for both the …

Msu Xtreme: Minnesota State University, Mankato's Entry Into The "Clean Snowmobile Challenge 2001", Scott Betcher, Allen Caldwell, Nathan Lindeman, Brian Mandelkow, Dave Maniak, Randy Rohlf, James Skuya, Dennis Swanson, Aaron Wolff, Mark Brandl, Dan Dobesh, Ryan Erickson, Jeff Gillen, Jan Smith, Jason Wilkie

Journal of Undergraduate Research at Minnesota State University, Mankato

Minnesota State University, Mankato’s Automotive Engineering Technology program formed a team to enter the Clean Snowmobile Challenge 2001. Selections for the organization’s machine included a 2001 Polaris Edge Chassis specially outfitted with a 2000 500 cc two-stroke Polaris engine. Modifications to the snowmobile were made specifically for Clean Snowmobile Challenge 2001 events. Acceleration, emissions, cold start, noise, fuel economy/range, handling/drivability, hill climb, and static display made up the list of events featured in the competition. MSU Xtreme has modified the snowmobile in every area with special emphasis on emissions and handling. Testing and analysis of the sled’s systems brought the …

Formula-Sae Wireless Data Logger, Eric Holland

Journal of Undergraduate Research at Minnesota State University, Mankato

The Formula-SAE (Society of Automotive Engineers) race car requires an onboard data logger to obtain and record the performance information received from the Fuel Injection Controller. This data is needed for analyzing the engine performance of the race car. It is advantageous to have this unit transmit the data via a wireless link to a handheld monitoring tool. Having user interface, like a LCD screen and a keypad, would make the monitoring tool easy to use. Also making the monitoring tool communicate with a PC would offer the beneficial features of saving and printing data. By having the PC connectivity, …

Applied Energy Systems - Rudimentary Thermodynamics, Jim Mcgovern

Book/Book Chapters

This is a compact textbook for a module addressing rudimentary thermodynamics within the context of applied energy systems. It is at an introductory level for engineers or technologists. The book does not attempt to cover the principles of thermodynamics comprehensively. Rather, it provides a practical but theoretically sound foundation, linked to some key areas. Energy, heat and work are all introduced, as are units and dimensions. Ideal gases and properties of liquids and vapours are treated. Non-flow and steady flow processes are described. Simple theory is provided for pumps and for the reciprocating compressor. Rudimentary steam and refrigeration or heat …

Effects Of Thermal Boundary Conditions During Finite Element Modeling Of Physical Vapor Transport, Wade Luhman

Journal of Undergraduate Research at Minnesota State University, Mankato

Physical vapor transport (PVT) is a material processing method commonly used to produce different types of semiconductor materials. Computer modeling of PVT is important to understand the fundamentals of the processing method. Due to the large amount of computer processing power and storage needed to solve the computer models many of the previously solved simulations have been simplified to efficiently utilize computer usage. Previous PVT computer simulations of mercurous chloride (Hg2Cl2) have assumed constant temperature profiles on the source and crystal substrate for simplicity. These simulations were performed using the FIDAP computational fluid dynamics software package. In this research the …

Compliant Joints Suitable For Use As Surrogate Folds, Isaac L. Delimont

Theses and Dissertations

Origami-inspired design is an emerging field capable of producing compact and efficient designs. The object of a surrogate fold is to provide a fold-like motion in a non-paper material without undergoing yielding. Compliant mechanisms provide a means to achieve these objectives as large deflections are achieved. The purpose of this thesis is to present a summary of existing compliant joints suitable for use as surrogate folds. In doing so, motions are characterized which no existing compliant joint provides. A series of compliant joints is proposed which provides many of these motions. The possibility of patterning compliant joints to form an …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Engineering Programs Receive Accreditation

Jet-Impingement Effects Of Alumina-Nanofluid On Aluminum And Copper, Gustavo J. Molina, Fnu Aktaruzzaman, Whitney Stregles, Valentin Soloiu, Mosfequr Rahman

Mechanical Engineering: Faculty Publications

Nanofluids are nanosize-powder suspensions that are of interest for their enhanced thermal transport properties. They are studied as promising alternatives to ordinary cooling fluids, but the tribiological effects of nanofluids on cooling-system materials are largely unknown. The authors have developed methodology that uses jet impingement on typical cooling-system materials to test such effects. The work is presented of the authors’ research on the interactions of a typical nanofluid (2% volume of alumina nanopowders in a solution of ethylene glycol in water) which is impinged on aluminum and copper specimens for tests as long as 112 hours. The surface changes were …

Natural Convection From Circular Cylinders, Sandra K. S. Boetcher

Publications

Chapter 1

Natural convection heat transfer from circular cylinders in quiescent environments is a subject which has been studied extensively. Although a well-established topic, to the best knowledge of the author no single source of reference is found for natural convection from circular cylinders for varying orientations (horizontal, vertical, and inclined). This book attempts to be a reference for Nusselt number correlations for circular cylinders of all inclinations including horizontal and vertical.

Shape Optimization Of Airfoils Without And With Ground Effect Using A Multi-Objective Genetic Algorithm, Yilei He

McKelvey School of Engineering Graduate Student Theses & Dissertations

The focus of this thesis is on shape optimization using a genetic algorithm. A multi-objective genetic algorithm (MOGA) is employed to optimize the shape of an airfoil to improve its lift and drag characteristics, in particular to achieve two objectives simultaneously that is to increase its lift as well as its lift to drag ratio. The commercially available software FLUENT is employed to calculate the flow field on an adaptive structured mesh, which is generated by the commercial mesh generating software ICEM. The flow field is calculated using the Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with a two equation k-ω …

Finite-Size Effects On Molecular Dynamics Interfacial Thermal-Resistance Predictions, Zhi Liang, Pawel Keblinski

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Using Molecular Dynamics Simulations, We Study the Role of Finite Size Effects on the Determination of Interfacial Thermal Resistance between Two Solids Characterized by High Phonon Mean Free Paths. in Particular, We Will Show that a Direct, Heat Source-Sink Method Leads to Strong Size Effect, Associated with Ballistic Phonon Transport to and From, and Specular Reflections at the Simulation Domain Boundary. Lack of Proper Account for These Effects Can Lead to Incorrect Predictions About the Role of Interfacial Bonding and Structure on Interfacial Thermal Resistance. We Also Show that the Finite Size Effect Can Be Dramatically Reduced by Introduction of …

Geometric Solution In Progressive Collapse Analysis Of Hull Girder, Ertekin Bayraktarkatal, Gökhan Tansel Tayyar

Journal of Marine Science and Technology–Taiwan

This paper presents a calculation model for stiffened plates to determine the ultimate strength of ship hull girders from their curvatures using a geometrical approach. The present study employed Smith’s method, in which the cross-section is divided into smaller elements consisting of a stiffener(s) and attached plating. The strength of beam-columns and stiffened plates was obtained using an iterative numerical approach. The deflection curve was evaluated using the curvature values directly instead of by solving differential equations. The deflection curve was taken as an assembly of chains of circular arcs. The ultimate strength of the hull girder of a 1/3 …

Evaluation Of The Performance Of Various Turbulence Models For Accurate Numerical Simulation Of A 2d Slot Nozzle Ejector, Colin Graham

McKelvey School of Engineering Graduate Student Theses & Dissertations

With the development over the last several decades, accurate Computational Fluid Dynamics (CFD) modeling has now become an essential part in the analysis and design of various industrial products where the fluid flow plays an important role. The goal of this thesis is to apply the CFD technology to the analysis of a 2D slot nozzle ejector which has application in Short Take-off and Landing (STOL) aircraft and other future aerospace vehicles. In the nozzle-ejector configuration, the high speed air flow from the nozzle entrains the ambient air into a mixing chamber (ejector) as a means to create additional thrust …

Three Dimensional Transient Asymmetric Flowfields In Physical Vapor Transport, Joseph Dobmeier

Journal of Undergraduate Research at Minnesota State University, Mankato

Physical Vapor Transport is a manufacturing process used to produce single crystals of semiconductor materials such as mercurous chloride (Hg2Cl2). In the past this time-varying process has been studied with numerical simulation by considering three dimensional flow using an axi-symmetric two dimensional model or by restricting the simulation to asymmetric two dimensional flow and dropping the assumption of axi-symmetry from the model. It is generally agreed that neither of these methods accurately represent the true behavior of the process. The purpose of this research was to extend the asymmetric two dimensional model to three dimensions thereby obtaining a solution which …

Therapeutic Potential Of Haptic Theradrive: An Affordable Robot/Computer System For Motivating Stroke Rehabilitation, Andrew Theriualt, Mark L. Nagurka, Michelle J. Johnson

Mechanical Engineering Faculty Research and Publications

There is a need for increased opportunities for effective neurorehabilitation services for stroke survivors outside the hospital environment. Efforts to develop low-cost robot/computer therapy solutions able to be deployed in home and community rehabilitation settings have been growing. Our long-term goal is to develop a very low-cost system for stroke rehabilitation that can use commercial gaming technology and support rehabilitation with stroke survivors at all functioning levels. This paper reports the results of experiments comparing the old and new TheraDrive systems in terms of ability to assist/resist subjects and the root-mean-square (RMS) trajectory tracking error. Data demonstrate that the new …