Mechanical Engineering Commons^™

A Multi-Scale Cfd Analysis Of Patient-Specific Geometries To Tailor Lvad Cannula Implantation Under Pulsatile Flow Conditions: An Investigation Aimed At Reducing Stroke Incidence In Lvads, Ray Prather

Electronic Theses and Dissertations

A Left Ventricular Assist Device (LVAD) is a mechanical pump that provides temporary circulatory support when used as bridge-to-transplantation and relieves workload demand placed on a failing heart allowing for myocardia recovery when used as destination therapy. Stroke is the most devastating complication after ventricular assist device (VAD) implantation, with an incidence of 14-47% over 3-6 months. This complication due to thrombus formation and subsequent transport through the vasculature to cerebral vessels continues to limit the widespread implementation of VAD therapy. Patient-specific computational fluid dynamics (CFD) analysis may elucidate ways to reduce this risk. We employed a multi-scale model of …

Mechanism Of Hip Dysplasia And Identification Of The Least Energy Path For Its Treatment By Using The Principle Of Stationary Potential Energy, Mohammed Abdulwahab M. Zwawi

Electronic Theses and Dissertations

Developmental dysplasia of the hip (DDH) is a common newborn condition where the femoral head is not located in its natural position in the acetabulum (hip socket). Several treatment methods are being implemented worldwide to treat this abnormal condition. One of the most effective methods of treatment is the use of Pavlik Harness, which directs the femoral head toward the natural position inside the acetabulum. This dissertation presents a developed method for identifying the least energy path that the femoral head would follow during reduction. This is achieved by utilizing a validated computational biomechanical model that allows the determination of …

Theoretical And Experimental Investigation Of The Cascading Nature Of Pressure-Swirl Atomization, Pretam Choudhury

Electronic Theses and Dissertations

Pressure swirl atomizers are commonly used in IC, aero-engines, and liquid propellant rocket combustion. Understanding the atomization process is important in order to enhance vaporization, mitigate soot formation, design of combustion chambers, and improve overall combustion efficiency. This work utilizes non-invasive techniques such as ultra -speed imaging, and Phase Doppler Particle Anemometry (PDPA) in order to investigate the cascade atomization process of pressure-swirl atomizers by examining swirling liquid film dynamics and the localized droplet characteristics of the resulting hollow cone spray. Specifically, experiments were conducted to examine these effects for three different nozzles with orifice diameters .3mm, .5mm, and .97mm. …

Pressurized Metal Bellows Shock Absorber For Space Applications., John Trautwein

Electronic Theses and Dissertations

Numerous spacecraft designs exist for exploring the surfaces of planetary bodies and each have their own advantages and disadvantages. All successful landings have been made by stationary landers or wheeled rovers that rely on one-time use mechanisms, such as crushable aluminum honeycomb shock absorbers or inflatable airbags, to reduce shock loading to the spacecraft during landing. The stationary lander is the simplest type of lander, but can only take data from one location. Wheeled rovers add complexity in exchange for mobility to explore different locations. Rovers are limited by the terrain they can traverse; rovers becoming stuck have ended missions. …

Development Of Velocity Profile Generating Screens For Gas Turbine Components, Joseph Tate

Electronic Theses and Dissertations

Laboratory experiments on components of complex systems such as gas turbines require many conditions to be met. Requirements to be met in order to simulate real world conditions include inlet flow conditions such as velocity profile, Reynold's number, and temperature. The methodology to be introduced designs a velocity profile generating screen to match real world conditions through the use of perforated plates. The velocity profile generating screen is an array of jets arranged in a manner to produce sections of different solidities, a ratio of area that obstructs fluid flow compared to that of the total area. In an effort …

Direct Numerical Simulation Of Three-Dimensional Gravity Current On A Uniform Slope, A. Ooi, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications

Gravity currents occur when fluids of different density are brought together. When gravity currents travel down a uniform slope, buoyancy effects become more important and changes the physical dynamics of its motion. In the present paper, we report data from full three-dimensional direct numerical simulation of gravity currents propagating down a uniform slope. Our data shows that in most cases, the gravity current evolve to a shape that is similar to a triangular wedge. The physical mechanisms leading to formation of this triangular shape and the dynamics of such a structure is presented

Accelerated Life Testing To Predict Service Life And Reliability For An Appliance Door Hinge, Seunghyeon Cheon, Hyunsoo Jeong, So Young Hwang, Seokmoo Hong, Naksoo Kim, Joseph P. Domblesky

Mechanical Engineering Faculty Research and Publications

Appliance manufacturers have traditionally performed physical testing using prototypes to assess reliability and service integrity of new product designs. However, for white goods where service lives are measured in years or decades, the use of endurance testing to analyze long time reliability is uneconomical. As accelerated life testing (ALT) is more efficient and less costly than traditional reliability testing, the methodology is finding increased usage by appliance manufacturers. In the present study, a simulation-based ALT approach was used to predict the service life of a polyacetal hinge cam from a consumer refrigerator. A predictive life stress model based on cumulative …

Pipeline Leak Detection, Marcia Golmohamadi

Masters Theses

"In the present research two techniques are applied for leak detection in pipelines. The first method is a hardware-based technique which uses ultrasonic wave's emission for pipeline inspection. Ultrasonic waves are propagated in the pipe walls and reflected signal from leakage will be used for pipe analysis. Several Pipes with various dimensions and characteristics are modeled by finite element method using ANSYS. Second order longitudinal modes of ultrasonic waves are emitted in their walls. For this purpose, excited frequency is calculated such that it excites the second order longitude mode. In order to investigate the behavior of emitted wave in …

Performance Oriented Adaptive Architectures With Guaranteed Bounds, Benjamin Gruenwald, Tansel Yucelen, Mario Fravolini

Mechanical and Aerospace Engineering Faculty Research & Creative Works

While adaptive control has been used in numerous applications to achieve given system stabilization or command following criteria, the ability to obtain a predictable transient performance is a challenging problem when there is no a priori knowledge about system uncertainties (e.g., their upper bounds and/or domains). In order to address this problem, a new method is presented in [1, 2] utilizing artificial basis functions in the update law of an adaptive control design. This approach is predicated on a gradient minimization procedure and achieves a predictable transient performance without inducing oscillations in the system response as the constant gain due …

Directional Thermal Emission From A Leaky-Wave Frequency-Selective Surface, Edward C. Kinzel, J. C. Ginn, L. A. Florence, B. A. Lail, G. D. Boreman

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Dynamic Mechanical Analysis And High Strain-Rate Energy Absorption Characteristics Of Vertically Aligned Carbon Nanotube (Vacnt) Reinforced Woven Fiber-Glass Composites, Kiyun Kim

Electronic Theses and Dissertations

No abstract provided.

Test 2124a: New Holland T8.380, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Development And Operation Of A Mobile Test Facility For Education, Christopher Davis

Dissertations, Master's Theses and Master's Reports

The automotive industry saw a large shift towards vehicle electrification after the turn of the century. It became necessary to ensure that new and existing engineers were qualified to design and calibrate these new systems. To ensure this training, Michigan Tech received a grant to develop a curriculum based around vehicle electrification. As part of this agenda, the Michigan Tech Mobile Laboratory was developed to provide hands-on training for professional engineers and technicians in hybrid electric vehicles and vehicle electrification. The Mobile Lab has since then increased the scope of the delivered curriculum to include other automotive areas and even …

Effect Of Impact Damage On Compression-Compression Fatigue Behavior Of Sandwich Composites, Ali M. Al-Sharif

Wayne State University Dissertations

The aim of this research work was to investigate the effect of impact damage on in-plane buckling and compression-compression fatigue behavior for a new sandwich structure made from E-glass/epoxy face sheets over end-grain balsa wood core. Low velocity impact tests were carried out using a drop-weight impact tower by impacting the sandwich beam at the center with energy level slightly higher than threshold energy level of 8.8 J. Edge-wise compression static tests were conducted for impacted and non-impacted samples to address energy absorption characteristics of these composites. Analytical and experimental investigations were carried out to measure critical buckling loads and …

Development Of A Thickness Accommodation Technique For Origami-Inspired Design, Bryce Edmondson

Theses and Dissertations

Designers are constantly searching for new sourcing of inspiration for innovative design. Recently, origami has gained interest as one of these potential sources. Origami literally translated from Japanese means “paper folding” where “oru” means “to fold” and “kami” means “paper”. Since paper is insufficient to solve many engineering design problems, designers must turn to other materials. These materials will inevitably be thicker than paper and will often require different folding techniques and considerations. This thesis provides background information describing previous methods to accommodate thickness in origami-inspired design, presents a newly developed technique to address limitations of other methods, and explores …

Radiation Heat Transfer In A Particulate Medium Using A Ray Tracing Method, Manish B. Patil

LSU Master's Theses

In the present work, a complete 3D simulation of ray tracing model is developed for studying the radiation heat transfer, associated with laser based additive manufacturing, in both thick and thin particulate beds by using the Monte Carlo method. Additional program is developed for creating different types of packing structures such as simple cubic, rhombohydral and random packing. The scattering mechanisms in the particulate beds for large opaque spheres are evaluated using the specular and diffuse reflection methods. Further, a novel approach has been added to the model to include isotropic, forward and backward scattering mechanisms for a medium which …

Simulating Energy Efficient Control Of Multiple-Compressor Compressed Air Systems, Sean Murphy, J. Kelly Kissock

Mechanical and Aerospace Engineering Faculty Publications

In many industrial facilities it is common for more than one air compressor to be operating simultaneously to meet the compressed air demand. The individual compressor set-points and how these compressors interact and respond to the facility demand have a significant impact on the compressed air system total power consumption and efficiency. In the past, compressors were staged by cascading the pressure band of each compressor in the system. Modern automatic sequencers now allow more intelligent and efficient staging of air compressors.

AirSim, a compressed air simulation tool, is now able to simulate multiple-compressor systems with pressure band and automatic …

Proceedings Of The 15th Annual Early Career Technical Conference (Front Matter), Ectc Coordinating Committee

Early Career Technical Journal (ECTJ)

Proceedings of the 15th Annual Early Career Technical Conference, November 7, 2015. School of Engineering, University of Alabama at Birmingham, Birmingham, Alabama; pp. i-x

Section 1: Bio-Medical/Bioengineering, Ectc Coordinating Committee

Early Career Technical Journal (ECTJ)

Proceedings of the 15th Annual Early Career Technical Conference, November 7, 2015. School of Engineering, University of Alabama at Birmingham, Birmingham, Alabama; pp. 1-36

Section 3: Dynamic Systems & Control, Ectc Coordinating Committee

Early Career Technical Journal (ECTJ)

Proceedings of the 15th Annual Early Career Technical Conference, November 7, 2015. School of Engineering, University of Alabama at Birmingham, Birmingham, Alabama; pp. 65-106

Section 5: Numerical Methods, Ectc Coordinating Committee

Early Career Technical Journal (ECTJ)

Proceedings of the 15th Annual Early Career Technical Conference, November 7, 2015. School of Engineering, University of Alabama at Birmingham, Birmingham, Alabama; pp. 151-165

Analysis Of Strain Distribution On Several Parts Of Human Lung During Mechanical Ventilation Breathing, Israr Bin M Ibrahim, Parya Aghasafari, Ramana Pidaparti

Early Career Technical Journal (ECTJ)

Section 1: Bio-Medical/Bioengineering; pp. 3-9

Proceedings Of The 15th Annual Early Career Technical Conference (Complete Issue), Ectc Coordinating Committee

Early Career Technical Journal (ECTJ)

Proceedings of the 15th Annual Early Career Technical Conference, November 7, 2015. School of Engineering, University of Alabama at Birmingham, Birmingham, Alabama

Feasibility Study Of Substituting The Ffr Invasive Procedure With Cfd Analysis For Assessment Of Human Coronary Artery Stenosis, Mohamed M. Selim, Ankur Gupta

Early Career Technical Journal (ECTJ)

Section 1: Bio-Medical/Bioengineering; pp. 10-16

A Millimeter-Wave Printed Antenna At 35 Ghz For Biomedical Applications, Vinhson La, Saeed I. Latif, David A. Nelson

Early Career Technical Journal (ECTJ)

Section 1: Bio-Medical/Bioengineering; pp. 17-21

Airflow Characteristics In Adult Upper 9 Generations Of Lung Model And Airway Changing (Aging) Effect Under Ventilated Breathing, Jongwon Kim, Ramana Pidaparti, Rebecca L. Heise, Angela M. Reynolds

Early Career Technical Journal (ECTJ)

Section 1: Bio-Medical/Bioengineering; pp. 22-27

Pultruded Glass-Graphite/Epoxy Hybrid Composites Subjected To Transverse High Strain-Rate Compression Loading, Muhammad Afrough, Tejas S. Pandya

Early Career Technical Journal (ECTJ)

Section 2: Materials, Design & Manufacturing; pp. 39-43

Ksu Autonomous Go-Kart Frame, Andrew Geiman, Kevin Mcfall

Early Career Technical Journal (ECTJ)

Section 2: Materials, Design & Manufacturing; pp. 44-51

Section 4: Heat Transfer, Energy Generation & Conversion, Ectc Coordinating Committee

Early Career Technical Journal (ECTJ)

Proceedings of the 15th Annual Early Career Technical Conference, November 7, 2015. School of Engineering, University of Alabama at Birmingham, Birmingham, Alabama; pp. 107-150

Azi-Drive: A Novel Thruster Mapper For Twin Propeller Maritime Vessels, Andrew Gray, Kevin French, Jacob Panikulam, Zach Goins, Eric Schwartz

Early Career Technical Journal (ECTJ)

Section 2: Materials, Design & Manufacturing; pp. 52-57