Engineering Commons^™

Flux Focusing Axial Magnetic Gear, Robert J. Rutherford

Undergraduate Research & Mentoring Program

Power transmission is traditionally achieved with a mechanical gear. These gears require maintenance, cause vibration, and have no overload protection. Magnetic gears (MGs) offer an innovative solution to these drawbacks as they do not require regular maintenance, have no need for lubrication, create very little acoustic noise, have built in overload protection and as a result of these advantages, have a longer lifetime of operation. The flux focusing axial magnetic gear (FFAMG) was assembled for future testing of power transmission, conversion, and generation applications.

Gears are used to transmit power by converting low speed-high torque rotary motion into high speed-low …

Deposition Velocity Dependence On Urban Morphology, Rawand Muzafar Rasheed

Undergraduate Research & Mentoring Program

Understanding the interactions between the atmospheric boundary layer and urban structures provides insights into emerging problems such as green building design as well as dispersion and deposition of pollutants on urban structures. Characterization of deposition velocity dependence through the naphthalene sublimation method on model urban structures is conducted herein where the analogous fundamental transport mechanisms of momentum and mass transport is obtained via mass of naphthalene transferred. Via wind tunnel experiments, results show that deposition velocity of naphthalene from urban structures increases with increased number of urban structures ahead of the point of investigation. This is attributed to the wakes …

Jet Bounce In Low Gravity, Caleb Turner

Undergraduate Research & Mentoring Program

Liquid jets rebound (‘bounce’) from superhydrophobic surfaces when they impinge at oblique angles. We call this interesting phenomena ‘jet bounce’ and in this work we investigate the phenomena at large length scales in a reduced gravitational environment. For example, for water at Reynolds numbers 0 < Re < 3500 and surface normal Weber numbers 0 < We < 60 we characterize the response of the jets on the hydrophobic surface in the brief 2.1s micro-gravity environment achieved using a drop tower. It is observed that by varying jet velocity, flow rate, jet diameter, and incident angle we observe up to four distinct regimes of behavior. The various regimes may be targeted for specific applications and we demonstrate a variety of unique jet bounce behaviors for applications such as no-touch, no-contact fluid-thermal transport for spacecraft unit operations such as contaminated water processing, device cooling, and cryogenic fluids transport and management.

Stable jet bounce from small diameter jet ≈ 1 mm and low impact angle. Characterizing Reynolds number ≈ 900 and normal Weber number ≤ 10 allow jet bounce to rebound in non-destructive behavior.

Conditional Averaging And Classification In The Near Wake Of A Wind Turbine Array Boundary Layer, Sarah E. Smith

Undergraduate Research & Mentoring Program

Flow perturbation induced by interaction with a turbine rotor produces considerable turbulence which can alter the productivity of subsequent units within a wind farm. Previous methods have characterized near wake vorticity of a single turbine as well as recovery distance for various turbine array configurations. This study aims to build from previous methods of analysis from the perspective of the rotor well within a turbine array and develop a model to examine points of significant imposition in relation to rotational effects. Hot wire anemometry was employed downstream of a turbine located in the middle of the third row in a …

The Effect Of Plasma On Graphene Quality In An Inductively Couple Plasma Chemical Vapor Deposition Reactor, Brendan Coyne

Undergraduate Research & Mentoring Program

Despite continued interest in research and application development, full scale graphene production is still limited by many factors including prohibitively high growth temperature requirements. Extremely high quality graphene growth is possible at high temperatures using chemical vapor deposition (CVD). Use of an inductively coupled plasma chemical vapor deposition (ICP CVD) reactor with the benefit of precursor gas decomposition through plasma generation, may provide possibility to reduce growth temperature. Herein, we report plasma’s effects on graphene growth by comparing growths of increasing power supplied to plasma generation and changes in precursor gas ratios. Plasma composition was characterized by ultraviolet and visible …

The Effectiveness Of Sanitary Inspections As A Risk Assessment Tool For Thermotolerant Coliform Bacteria Contamination Of Rural Drinking Water: A Review Of Data From West Bengal, India, Christian Snoad, Corey L. Nagel, Animesh Bhattacharya, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

The use of sanitary inspections combined with periodic water quality testing has been recommended in some cases as screening tools for fecal contamination. We conducted sanitary inspections and tested for thermotolerant coliforms (TTCs), a fecal indicator bacteria, among 7,317 unique water sources in West Bengal, India. Our results indicate that the sanitary inspection score has poor ability to identify TTC-contaminated sources. Among deep and shallow hand pumps, the area under curve (AUC) for prediction of TTC > 0 was 0.58 (95% confidence interval [CI] = 0.53–0.61) and 0.58 (95% CI = 0.54–0.62), respectively, indicating that the sanitary inspection score was only …

Development And Training Of A Neural Controller For Hind Leg Walking In A Dog Robot, Alexander J. Hunt, Nicholas Szczecinski, Roger Quinn

Mechanical and Materials Engineering Faculty Publications and Presentations

Animals dynamically adapt to varying terrain and small perturbations with remarkable ease. These adaptations arise from complex interactions between the environment and biomechanical and neural components of the animal’s body and nervous system. Research into mammalian locomotion has resulted in several neural and neuro-mechanical models, some of which have been tested in simulation, but few “synthetic nervous systems” have been implemented in physical hardware models of animal systems. One reason is that the implementation into a physical system is not straightforward. For example, it is difficult to make robotic actuators and sensors that model those in the animal. Therefore, even …

Reversible Control Of The Magnetization Of Fe₃O₄ Via Lithium Ions, Guodong Wei, Lin Wei, Dong Wang, Yufeng Tian, Yanxue Chen, Shishen Yan, Liangmo Mei, Jun Jiao

Mechanical and Materials Engineering Faculty Publications and Presentations

In this report, a reversible control of Fe₃O₄ saturated magnetization by Li ions is demonstrated. A miniature Li ion battery (LIB) was assembled using a Fe₃O₄ nanoparticle layer as the active cathode. A stable magnetism modulation is realized by a nondestructive electrochemical process in which the lithium insertion results in a valence change and partial redistribution of Fe cations in the crystal structure. The relation between the discharge voltage and the chemical phases were studied by ex situ X-ray diffraction and magnetic measurement. In a suitable discharge potential range, a reversible control of Fe₃O₄ saturated magnetization was obtained without structural …

Anisotropic Character Of Low-Order Turbulent Flow Descriptions Through The Proper Orthogonal Decomposition, Nicholas Hamilton, Murat Tutkun, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Proper orthogonal decomposition (POD) is applied to distinct data sets in order to characterize the propagation of error arising from basis truncation in the description of turbulence. Experimental data from stereo particle image velocimetry measurements in a wind turbine array and direct numerical simulation data from a fully developed channel flow are used to illustrate dependence of the anisotropy tensor invariants as a function of POD modes used in low-order descriptions. In all cases, ensembles of snapshots illuminate a variety of anisotropic states of turbulence. In the near wake of a model wind turbine, the turbulence field reflects the periodic …

Fifty-Plus-Year Postflight Analysis Of First Fluid Experiment Aboard A Spacecraft, Mark M. Weislogel, Yongkang Chen, William J. Masica, Fred J. Kohl, Robert D. Green

Mechanical and Materials Engineering Faculty Publications and Presentations

This year marks the 55th anniversary of the first fluid physics experiment performed aboard a spacecraft during the Mercury-Atlas 7 mission. Since then, NASA has conducted over 80 fluids physics experiments aboard a variety of spacecraft, many of which have enhanced the understanding of large-length-scale capillary phenomena relevant to liquid management in the weightless state. As both celebration and demonstration, the Mercury-Atlas 7 fluids experiment is revisited in light of the current understanding of large-length-scale capillary fluidics. Employing a modern numerical tool, a rich variety of experimental outcomes are discovered that were not observed during the flight experiment. Interestingly, experimental …

Reversible Control Of The Magnetization Of Spinel Ferrites Based Electrodes By Lithium-Ion Migration, Guodong Wei, Lin Wei, Dong Wang, Yanxue Chen, Yufeng Tian, Shishen Yan, Liangmo Mei, Jun Jiao

Mechanical and Materials Engineering Faculty Publications and Presentations

Lithium-ion (Li-ion) batteries based on spinel transition-metal oxide electrodes have exhibited excellent electrochemical performance. The reversible intercalation/deintercalation of Li-ions in spinel materials enables not only energy storage but also nondestructive control of the electrodes’ physical properties. This feature will beneft the fabrication of novel Li-ion controlled electronic devices. In this work, reversible control of ferromagnetism was realized by the guided motion of Li-ions in MnFe₂O₄ and γ-Fe₂O₃ utilizing miniature lithium-battery devices. The in-situ characterization of magnetization during the Li-ion intercalation/deintercalation process was conducted, and a reversible variation of saturation magnetization over 10% was observed …