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2019

Mechanical Engineering

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Articles 1 - 30 of 647

Full-Text Articles in Engineering

Rapid Prediction Of Low-Boom And Aerodynamic Performance Of Supersonic Transport Aircraft Using Panel Methods, Ted N. Giblette Dec 2019

Rapid Prediction Of Low-Boom And Aerodynamic Performance Of Supersonic Transport Aircraft Using Panel Methods, Ted N. Giblette

All Graduate Theses and Dissertations

The Utah State University Aerolab developed and tested a set of tools for rapid prediction of the loudness of a sonic boom generated by supersonic transport aircraft. This work supported a larger effort led by Texas A&M to investigate the use of adaptive aerostructures in lowering sonic boom loudness at off design conditions. Successful completion of this effort will improve the feasibility of supersonic commercial transport over land.

Funding was provided by a NASA University Leadership Initiative grant to several universities, including Utah State University, as well as industry partners to complete this work over a five year period ...


Spontaneous Emission Rate Enhancement With Aperiodic Thue-Morse Multilayer, Ling Li, Cherian J. Mathai, Shubhra Gangopadhyay, Xiaodong Yang, Jie Gao Dec 2019

Spontaneous Emission Rate Enhancement With Aperiodic Thue-Morse Multilayer, Ling Li, Cherian J. Mathai, Shubhra Gangopadhyay, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The emergence of multilayer metamaterials in the research field of enhancing spontaneous emission rates has recently received extensive attention. Previous research efforts mostly focus on periodic metal-dielectric multilayers in hyperbolic dispersion region; however, the influence of lattice order in subwavelength multilayers on spontaneous emission is rarely studied. Here, we observe the stronger Purcell enhancement of quantum dots coupled to the aperiodic metal-dielectric multilayer with Thue-Morse lattice order from elliptical to hyperbolic dispersion regions, compared to the periodic multilayer with the same metal filling ratio. This work demonstrates the potential of utilizing quasiperiodic metamaterial nanostructures to engineer the local density of ...


3d Janus Plasmonic Helical Nanoapertures For Polarization-Encrypted Data Storage, Yang Chen, Xiaodong Yang, Jie Gao Dec 2019

3d Janus Plasmonic Helical Nanoapertures For Polarization-Encrypted Data Storage, Yang Chen, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Helical structures have attracted considerable attention due to their inherent optical chirality. Here, we report a unique type of 3D Janus plasmonic helical nanoaperture with direction-controlled polarization sensitivity, which is simply fabricated via the one-step grayscale focused ion beam milling method. Circular dichroism in transmission of as large as 0.72 is experimentally realized in the forward direction due to the spin-dependent mode coupling process inside the helical nanoaperture. However, in the backward direction, the nanoaperture acquires giant linear dichroism in transmission of up to 0.87. By encoding the Janus metasurface with the two nanoaperture enantiomers having specified rotation ...


Pore Elimination Mechanisms During 3d Printing Of Metals, S. Mohammad H. Hojjatzadeh, Niranjan D. Parab, Wentao Yan, Lianyi Chen, For Full List Of Authors, See Publisher's Website. Dec 2019

Pore Elimination Mechanisms During 3d Printing Of Metals, S. Mohammad H. Hojjatzadeh, Niranjan D. Parab, Wentao Yan, Lianyi Chen, For Full List Of Authors, See Publisher's Website.

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser powder bed fusion (LPBF) is a 3D printing technology that can print metal parts with complex geometries without the design constraints of traditional manufacturing routes. However, the parts printed by LPBF normally contain many more pores than those made by conventional methods, which severely deteriorates their properties. Here, by combining in-situ high-speed high-resolution synchrotron x-ray imaging experiments and multi-physics modeling, we unveil the dynamics and mechanisms of pore motion and elimination in the LPBF process. We find that the high thermocapillary force, induced by the high temperature gradient in the laser interaction region, can rapidly eliminate pores from the ...


Spatial Variation Of Vector Vortex Beams With Plasmonic Metasurfaces, Yuchao Zhang, Jie Gao, Xiaodong Yang Dec 2019

Spatial Variation Of Vector Vortex Beams With Plasmonic Metasurfaces, Yuchao Zhang, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The spatial variation of vector vortex beams with arbitrary polarization states and orbital angular momentum (OAM) values along the beam propagation is demonstrated by using plasmonic metasurfaces with the initial geometric phase profiles determined from the caustic theory. The vector vortex beam is produced by the superposition of deflected right- and left-handed circularly polarized component vortices with different helical phase charges, which are simultaneously generated off-axially by the single metasurface. Besides, the detailed evolution processes of intensity profile, polarization distribution and OAM value along the beam propagation distance is analyzed. The demonstrated arbitrary space-variant vector vortex beam will pave the ...


Viscoelastic Properties Of Shock Wave Exposed Brain Tissue Subjected To Unconfined Compression Experiments, Annastacia K. Mccarty, Ling Zhang, Sarah Hansen, William J. Jackson, Sarah A. Bentil Dec 2019

Viscoelastic Properties Of Shock Wave Exposed Brain Tissue Subjected To Unconfined Compression Experiments, Annastacia K. Mccarty, Ling Zhang, Sarah Hansen, William J. Jackson, Sarah A. Bentil

Mechanical Engineering Publications

Traumatic brain injuries (TBI) affect millions of people each year. While research has been dedicated to determining the mechanical properties of the uninjured brain, there has been a lack of investigation on the mechanical properties of the brain after experiencing a primary blast-induced TBI. In this paper, whole porcine brains were exposed to a shock wave to simulate blast-induced TBI. First, ten (10) brains were subjected to unconfined compression experiments immediately following shock wave exposure. In addition, 22 brains exposed to a shock wave were placed in saline solution and refrigerated between 30 minutes and 6.0 hours before undergoing ...


Orbital Angular Momentum Transformation Of Optical Vortex With Aluminum Metasurfaces, Yuchao Zhang, Xiaodong Yang, Jie Gao Dec 2019

Orbital Angular Momentum Transformation Of Optical Vortex With Aluminum Metasurfaces, Yuchao Zhang, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The orbital angular momentum (OAM) transformation of optical vortex is realized upon using aluminum metasurfaces with phase distributions derived from the caustic theory. The generated OAM transformation beam has the well-defined Bessel-like patterns with multiple designed topological charges from -1 to +2.5 including both the integer-order and fractional-order optical vortices along the propagation. The detailed OAM transformation process is observed in terms of the variations of both beam intensity and phase profiles. The dynamic distributions of OAM mode density in the transformation are further analyzed to illustrate the conservation of the total OAM. The demonstration of transforming OAM states ...


Second-Harmonic Optical Vortex Conversion From Ws₂ Monolayer, Arindam Dasgupta, Jie Gao, Xiaodong Yang Dec 2019

Second-Harmonic Optical Vortex Conversion From Ws₂ Monolayer, Arindam Dasgupta, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Wavelength, polarization and orbital angular momentum of light are important degrees of freedom for processing and encoding information in optical communication. Over the years, the generation and conversion of orbital angular momentum in nonlinear optical media has found many novel applications in the context of optical communication and quantum information processing. With that hindsight, here orbital angular momentum conversion of optical vortices through second-harmonic generation from only one atomically thin WS2 monolayer is demonstrated at room temperature. Moreover, it is shown that the valley-contrasting physics associated with the nonlinear optical selection rule in WS2 monolayer precisely determines the output circular ...


Ndbc Ocean Wave Observation System Update, Rodney Riley, Randy Stewart, Steven Dinapoli Oct 2019

Ndbc Ocean Wave Observation System Update, Rodney Riley, Randy Stewart, Steven Dinapoli

Ocean Waves Workshop

The U.S. National Oceanic and Atmospheric Administration’s (NOAA) National Data Buoy Center (NDBC) is modifying its ocean wave observation system due to parts obsolescence. The modified system is named Ocean Wave Linux (OWL). OWL will replace the NDBC’s older and now obsolete Digital Directional Wave Module (DDWM). Once OWL completes operational verification, the DDWM will be phased out of the NDBC’s operational weather buoy network.


Performance Characteristics Of The Spotter: A New Developed Wave Measurement Buoy, Kaus Raghukumar, Grace Chang, Frank Spada, Craig Jones, Tim Jannsen Oct 2019

Performance Characteristics Of The Spotter: A New Developed Wave Measurement Buoy, Kaus Raghukumar, Grace Chang, Frank Spada, Craig Jones, Tim Jannsen

Ocean Waves Workshop

The Spotter is a low-cost, real-time, solar powered wave measurement buoy that was recently developed by Sofar Technologies, Inc. (formerly Spoondrift). To evaluate the data quality of the Spotter device, we performed a series of validation experiments that included comparisons between Spotter-derived motions and prescribed wave motions (monochromatic and random waves) on a custom-built, motion-controlled validation stand, and simultaneous in-water measurements using a conventional wave measurement buoy, the Datawell DWR-G4 (Datawell).


Achieving Energy Justice In Low Income Communities: Creating A Community-Driven Program For Residential Energy Savings, Anya Galli Robertson, Kevin Hallinan, Jennifer Hoody Oct 2019

Achieving Energy Justice In Low Income Communities: Creating A Community-Driven Program For Residential Energy Savings, Anya Galli Robertson, Kevin Hallinan, Jennifer Hoody

Conference: The Social Practice of Human Rights

The cost of residential energy the U.S. is unequally distributed, with low income households paying higher rates and spending 16.8% of their income on utility bills compared to 3.5% of all U.S. Residents.[1] Researchers have found that bringing the housing stock up to the efficiency of the median household would reduce excess energy cost by as much as 68%.[2] However, access to opportunities to reduce residential energy consumption and costs such as tax incentives and utility rebate programs tends to be biased toward wealthier, white homeowners. Additionally, low income residents are most likely to ...


The Improvement Of The Solar Air Heater Duct By Wired Ribs Utilization, Osamah Raad Skheel/Alkhafaji Sep 2019

The Improvement Of The Solar Air Heater Duct By Wired Ribs Utilization, Osamah Raad Skheel/Alkhafaji

Karbala International Journal of Modern Science

Abstract Heat transfer coefficient of the solar air heater duct (SAH) is low due increasing the thermal performance of its absorber. The present study tends to enhance the thermal characteristics of the SAH by adopting the wired ribs on the absorber under different ribs dimensions and arrangements. A rectangular duct is used to form the SAH with length L=1500mm, width w=100mm and height H=30mm. The used heat fluxes over the absorber are 1000W/m2 and 500W/m2 while the operated Reynolds number range is 708 ~ 6375. The utilized wired ribs are arranged over the absorber so as ...


Analytical Approach To Investigation Of Free Vibration Of Thin Rectangular Plate Immersed In Fluid, Resting On Winkler And Pasternak Foundations, Obanishola Safiq, Gbeminiyi Sobamowo, Saheed Salawu Sep 2019

Analytical Approach To Investigation Of Free Vibration Of Thin Rectangular Plate Immersed In Fluid, Resting On Winkler And Pasternak Foundations, Obanishola Safiq, Gbeminiyi Sobamowo, Saheed Salawu

Karbala International Journal of Modern Science

Dynamic behaviour of free vibration of rectangular plate is investigated. This study considered an analytical approach to investigation of free vibration of thin rectangular plate immersed in fluid, resting on Winkler and Pasternak foundations.The governing nonlinear partial differential equation is analyzed using two-dimensional differential transform method. The accuracy of the analytical solutions obtained is verified with existing results in literature and confirmed in excellent agreement. Thereafter, the analytical solutions are used for investigation of effect of elastic foundation, fluid and aspect ratio on vibrating plate.From the result, it is observed that, increase elastic foundation parameters increases natural frequency ...


Crash Safety In The Introductory Physics Lab, Daniel Ludwigsen, Janet Brelin-Fornari, Joseph Neal Sep 2019

Crash Safety In The Introductory Physics Lab, Daniel Ludwigsen, Janet Brelin-Fornari, Joseph Neal

Daniel Ludwigsen

Crash Safety in the Introductory Physics Lab Abstract In the field of vehicle occupant protection and crash safety, the Deceleration Sled offers researchers a controlled, repeatable, and relatively cost-effective means to test interior parts such as safety restraint systems. The sled can accelerate a 2000 lb payload to achieve a speed of 40 mph before a hydraulically controlled deceleration models the deformation of the vehicle structure during a crash. Understanding the dynamics of the sled and interpreting test results incorporates many of the core concepts of a first course in introductory physics. This application of physics principles is the inspiration ...


Developing A Workflow To Integrate Tree Inventory Data Into Urban Energy Models, Farzad Hashemi, Breanna L. Marmur, Ulrike Passe, Janette R. Thompson Sep 2019

Developing A Workflow To Integrate Tree Inventory Data Into Urban Energy Models, Farzad Hashemi, Breanna L. Marmur, Ulrike Passe, Janette R. Thompson

Ulrike Passe

Building energy simulation is of considerable interest and benefit for architects, engineers, and urban planners. Only recently has it become possible to develop integrated energy models for clusters of buildings in urban areas. Simulating energy consumption of the built environment on a relatively large scale (e.g., such as a neighborhood) will be necessary to obtain more reliable results, since building energy parameters are influenced by characteristics of the nearby environment. Therefore, the construction of a 3-D model of urban built areas with detail of the near-building environment should enhance simulation approaches and provide more accurate results. This paper describes ...


The Use Of Sacrificial Support Structures In A Rapid Machining Process, Wutthigrai Boonsuk, Matthew C. Frank Sep 2019

The Use Of Sacrificial Support Structures In A Rapid Machining Process, Wutthigrai Boonsuk, Matthew C. Frank

Wutthigrai Boonsuk

Rapid prototyping techniques for CNC machining have been developed in an effort to produce functional prototypes in appropriate materials. One of the major challenges is to develop an automatic fixturing system for the part during the milling process. The current proposed method, sacrificial support fixturing, is similar to the support structures used in existing rapid processes, such as Stereolithography. During the machining process, the sacrificial supports emerge incrementally and, at the end of the process, are the only entities connecting the part to the stock material. In this paper, we propose methodologies for the design of sacrificial support structures for ...


Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson Sep 2019

Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson

Protocols and Reports

The process of transferring a monolayer of graphene using two different concentrations of sodium hydroxide (NaOH) solution unto a silicon dioxide (SiO2) coated Si chip using electrochemistry was performed. The transfer process is crucial for the delamination of a continuous graphene monolayer film from copper foil. After examining and inspecting the integrity of the graphene monolayer, it was observed that the lower concentration to NaOH led to slower rate of hydrogen bubble generation; this condition was found to be less destructive and yielded a graphene film with fewer visible tears.


The Hydrodynamics And Heat Transfer Of Impinging Jet Flow And Circular Hydraulic Jump, Yunpeng Wang Sep 2019

The Hydrodynamics And Heat Transfer Of Impinging Jet Flow And Circular Hydraulic Jump, Yunpeng Wang

Electronic Thesis and Dissertation Repository

The laminar axisymmetric flow and heat transfer of a circular impinging jet and hydraulic jump on a solid surface is analyzed theoretically using boundary-layer and thin-film approaches. Liquid jet impingement features many applications such as jet rinsing, jet cooling, liquid atomization and chemical reactors. The associated hydraulic jump dramatically affects the performance of the heat and mass transfer in such applications. In the current thesis, the effects of inertia, surface tension, surface rotation, gravity and heat transfer are comprehensively explored for impinging jet flow and the formation of hydraulic jump.

The boundary-layer heights and film thickness are found to diminish ...


Pre-Methylation Of Lignin To Improve Storage Stability Of Oil Produced By Solvent Liquefaction, Jae-Young Kim, Parinaz Hafezi-Sefat, Sarah D. Cady, Ryan G. Smith, Robert C. Brown Sep 2019

Pre-Methylation Of Lignin To Improve Storage Stability Of Oil Produced By Solvent Liquefaction, Jae-Young Kim, Parinaz Hafezi-Sefat, Sarah D. Cady, Ryan G. Smith, Robert C. Brown

Sarah Cady

In this study, we methylated hydroxyl groups (phenolic hydroxyl: Phe-OH and aliphatic hydroxyl: Aliph-OH) in soda lignin (SL) prior to solvent liquefaction to improve storage stability of the resulting oil. We investigated two methylating reagents, dimethyl sulfate (DMS) and dimethyl carbonate (DMC), for selective Phe-OH and total hydroxyl group (Phe-OH and Aliph-OH) blocking. Samples of SL, DMS-SL, and DMC-SL were depolymerized into oils under supercritical ethanol (350 °C). Both methylated lignins produced higher amounts of oils and smaller amounts of char compared to untreated SL due to suppressed charring reactions. Oil produced from SL had relatively higher functional group contents ...


The Impact Of Patient-Specific Vascular Structure On Localized Cooling In The Human Heart, Nathan Paul Spangenberg Sep 2019

The Impact Of Patient-Specific Vascular Structure On Localized Cooling In The Human Heart, Nathan Paul Spangenberg

Theses and Dissertations

Acute Myocardial Infarction (AMI) is the leading cause of worldwide death and disability, and approximately 720,000 Americans will experience an AMI in 2018. Studies have shown that rapid hypothermia therapy (<35°C) before reperfusion in patients with AMI can reduce infarct size by 37%. Localized therapeutic hypothermia has proven the potential to cool heart tissue rapidly following AMI, 3°C in 5 minutes. Using Materialise Mimics digital imaging software and the finite volume method we analyzed temperature distributions in six patient-specific left main coronary artery (LMCA) models. A mock circulatory loop was used to determine the exiting temperatures of a standard 7 Fr catheter to feed into our model with flow rates ranging from 29.2 ml/min to 68.85 ml/min. Our work showed that therapeutic hypothermia (TH) temperatures were evident at the outlets of three out of all six heart models, which varied in each left anterior descending (LAD) and left circumflex (LCX) artery depending on flowrate. Results of this study indicate that biovariability in patient-specific vascular structures significantly impacts therapeutic hypothermia (TH) treatment methods. These results indicate that further research is needed to examine more accurate physiological effects, such as pulsatile flow and vessel wall thickness. Future models will be used to provide insight to guide more efficient TH device designs and operation parameters to optimize patient outcomes following AMI.


Pairing Electrostatic Levitation With Triboelectric Transduction For High-Performance Self-Powered Mems Sensors And Actuators, Mark Pallay, Alwathiqbellah I. Ibrahim, Ronald N. Miles, Shahrzad Towfighian Sep 2019

Pairing Electrostatic Levitation With Triboelectric Transduction For High-Performance Self-Powered Mems Sensors And Actuators, Mark Pallay, Alwathiqbellah I. Ibrahim, Ronald N. Miles, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

We demonstrate that an electrostatic levitation MEMS switch can be operated by applying mechanical pres- sure to a triboelectric generator. The toggling mechanism of the switch draws no current but requires a high actuating voltage, while the generator can supply a high voltage but only produces microwatts of power. The synergistic combination results in an entirely self-powered sensor and switch; the normally-closed MEMS switch can be toggled open by applying a threshold force to the generator without the need for any outside power or supplementary circuitry. A model of the MEMS switch and electrostatic force is validated with experimental data ...


Initial Development Of A Prototype Sensor Testbed For Fetal Monitoring, Christian Beauvais Aug 2019

Initial Development Of A Prototype Sensor Testbed For Fetal Monitoring, Christian Beauvais

Theses and Dissertations

The objective of this research is to design and manufacture a device that exhibits some of the bio-physiological signals relevant to fetal health monitoring. Currently, limited options exist for testing the performance of monitoring devices such as the tocodynamometer (TOCO) and electrocardiograph (ECG) that measure the bio-physiological signals of a woman and her fetus. Sensor designers need ways of generating and acquiring signals that do not carry the ethical burden of human testing. The development of such a device, as considered in this work, may involve using muscle wire or an inflatable tube as prospective foundations for simulating uterine contraction ...


Plant Disease Identification Using Explainable 3d Deep Learning On Hyperspectral Images, Koushik Nagasubramanian, Sarah Jones, Asheesh K. Singh, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian Aug 2019

Plant Disease Identification Using Explainable 3d Deep Learning On Hyperspectral Images, Koushik Nagasubramanian, Sarah Jones, Asheesh K. Singh, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian

Baskar Ganapathysubramanian

Background

Hyperspectral imaging is emerging as a promising approach for plant disease identification. The large and possibly redundant information contained in hyperspectral data cubes makes deep learning based identification of plant diseases a natural fit. Here, we deploy a novel 3D deep convolutional neural network (DCNN) that directly assimilates the hyperspectral data. Furthermore, we interrogate the learnt model to produce physiologically meaningful explanations. We focus on an economically important disease, charcoal rot, which is a soil borne fungal disease that affects the yield of soybean crops worldwide.

Results

Based on hyperspectral imaging of inoculated and mock-inoculated stem images, our 3D ...


Computational Finite Element Analysis Of Adaptive Gas Turbine Stator-Rotor Flow Interactions For Future Vertical Lift Propulsion, Nikita Kozak, Luis Bravo, Muthuvel Murugan, Anindya Ghoshal, Yu Yu Khine, Yuri Bazilevs, Ming-Chen Hsu Aug 2019

Computational Finite Element Analysis Of Adaptive Gas Turbine Stator-Rotor Flow Interactions For Future Vertical Lift Propulsion, Nikita Kozak, Luis Bravo, Muthuvel Murugan, Anindya Ghoshal, Yu Yu Khine, Yuri Bazilevs, Ming-Chen Hsu

Ming-Chen Hsu

The objective of this work is to computationally investigate the impact of an incident-tolerant rotor blade concept on gas-turbine engine performance under off-design conditions. Currently, gas-turbine engines are designed to operate at a single condition with nearly fixed rotor speeds. Operation at off-design conditions, such as during hover flight or during takeoff, causes the turbine blade flow to excessively separate introducing performance degradations, excessive noise, and critical loss of operability. To address these issues, the benefits of using an incidence-tolerant rotor blade concept is explored based on a novel concept that articulates the rotating turbine blade synchronously with the stator ...


Deformation Of Multifunctional Materials At Various Time And Length Scales: A Dic-Based Study, Behrad Koohbor Aug 2019

Deformation Of Multifunctional Materials At Various Time And Length Scales: A Dic-Based Study, Behrad Koohbor

Behrad Koohbor

The focus in the present work is to explore and characterize the underlying deformation and failure mechanisms in multifunctional materials including woven composites and polymeric foams, using full-field measurements. Attention has been especially drawn towards the challenges associated with characterizing these materials at extreme length and time scales, and investigating the advantages of full-field measurements to resolve the existing limitations. Accordingly, the current limitations in the study of dynamic deformation response of low-impedance materials are identified. An approach based on the general stress equilibrium is presented and successfully implemented to include the concurrent effects of inertia and material compressibility into ...


Locomotion Of A Cylindrical Rolling Robot With A Shape Changing Outer Surface, Michael G. Puopolo, Jamey D. Jacob, Emilio Gabino Aug 2019

Locomotion Of A Cylindrical Rolling Robot With A Shape Changing Outer Surface, Michael G. Puopolo, Jamey D. Jacob, Emilio Gabino

Michael G. Puopolo

A cylindrical rolling robot is developed that generates roll torque by changing the shape of its flexible, elliptical outer surface whenever one of four elliptical axes rotates past an inclination called trigger angle. The robot is equipped with a sensing/control system by which it measures angular position and angular velocity, and computes error with respect to a desired step angular velocity profile. When shape change is triggered, the newly assumed shape of the outer surface is determined according to the computed error. A series of trial rolls is conducted using various trigger angles, and energy consumed by the actuation ...


An Experimental Study On The Impact Of Pressure Drop In The Ranque-Hilsch Vortex Tube, Mark Parker Aug 2019

An Experimental Study On The Impact Of Pressure Drop In The Ranque-Hilsch Vortex Tube, Mark Parker

Electronic Thesis and Dissertation Repository

A vortex tube converts a single stream of compressed gas into two outlet streams; one heated, and the other cooled. This phenomenon, referred to as energy separation, is not fully understood, thereby requires further experimentation and analysis. CFD can provide insight, however, such simulations require a complete set of information of the geometric, operational, and performance parameters of particular vortex tube experiments.

An experiment is developed to provide complete information for CFD simulations. The vortex tube under consideration is established by considering reported data from past studies and selecting parameters that yield significant energy separation. An experimental apparatus is developed ...


Plant Disease Identification Using Explainable 3d Deep Learning On Hyperspectral Images, Koushik Nagasubramanian, Sarah Jones, Asheesh K. Singh, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian Aug 2019

Plant Disease Identification Using Explainable 3d Deep Learning On Hyperspectral Images, Koushik Nagasubramanian, Sarah Jones, Asheesh K. Singh, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian

Mechanical Engineering Publications

Background

Hyperspectral imaging is emerging as a promising approach for plant disease identification. The large and possibly redundant information contained in hyperspectral data cubes makes deep learning based identification of plant diseases a natural fit. Here, we deploy a novel 3D deep convolutional neural network (DCNN) that directly assimilates the hyperspectral data. Furthermore, we interrogate the learnt model to produce physiologically meaningful explanations. We focus on an economically important disease, charcoal rot, which is a soil borne fungal disease that affects the yield of soybean crops worldwide.

Results

Based on hyperspectral imaging of inoculated and mock-inoculated stem images, our 3D ...


In Vitro Biomechanical Analyses Of The Pcl And Medial Ligaments Of The Human Knee, Alireza Moslemian Aug 2019

In Vitro Biomechanical Analyses Of The Pcl And Medial Ligaments Of The Human Knee, Alireza Moslemian

Electronic Thesis and Dissertation Repository

Previous studies have shown that surgical treatments of PCL injuries are not successful in all cases and there is room for improvement. The effectiveness of an isolated PCL reconstruction, in the setting of what actually is a multi-ligament injury, may be inadequate, and therefore the biomechanical contribution of other ligaments in a PCL-deficient knee need to be better understood.

A new apparatus was used to analyze the effect of medial ligaments transection on the kinematics of the PCL-deficient knee during simulated clinical tests and activities of daily living. We observed that the anterior translation of the medial side of the ...


Computational Finite Element Analysis Of Adaptive Gas Turbine Stator-Rotor Flow Interactions For Future Vertical Lift Propulsion, Nikita Kozak, Luis Bravo, Muthuvel Murugan, Anindya Ghoshal, Yu Yu Khine, Yuri Bazilevs, Ming-Chen Hsu Aug 2019

Computational Finite Element Analysis Of Adaptive Gas Turbine Stator-Rotor Flow Interactions For Future Vertical Lift Propulsion, Nikita Kozak, Luis Bravo, Muthuvel Murugan, Anindya Ghoshal, Yu Yu Khine, Yuri Bazilevs, Ming-Chen Hsu

Mechanical Engineering Conference Presentations, Papers, and Proceedings

The objective of this work is to computationally investigate the impact of an incident-tolerant rotor blade concept on gas-turbine engine performance under off-design conditions. Currently, gas-turbine engines are designed to operate at a single condition with nearly fixed rotor speeds. Operation at off-design conditions, such as during hover flight or during takeoff, causes the turbine blade flow to excessively separate introducing performance degradations, excessive noise, and critical loss of operability. To address these issues, the benefits of using an incidence-tolerant rotor blade concept is explored based on a novel concept that articulates the rotating turbine blade synchronously with the stator ...