Mechanical Engineering Commons^™

Numerical Study On Oscillating Flow Over A Flat Plate Using Pseudo-Compressibility In Intermittent Turbulent Regime, Shivank Srivastava Mr.

LSU New Orleans Theses and Dissertations

A Computational Fluid Dynamic (CFD) in-house code is developed to study unsteady characteristics of incompressible oscillating boundary layer flow over a flat plate under laminar and intermittently turbulent condition using pseudo-compressible unsteady Reynolds Averaged Navier- Stokes (RANS) model. In the in-house code, the two-dimensional, unsteady conservation of mass and momentum equations are discretized using finite difference techniques which employs second order accurate (based on Taylor series) central differencing for spatial derivatives and second order Runge-Kutta accurate differencing for temporal derivatives. The in-house code employs Fully Explicit-Finite Difference technique (FEFD) to solve the governing differential equations of the mathematical model. In …

Investigation Of Two-Phase Flow Phenomena In Rotating Paper Dryer To Achieve Effective Heat Transfer With Low Energy Consumption, Hamed Abdul Majeed

LSU New Orleans Theses and Dissertations

The paper industry provides important consumer products comprised of paper, tissue, paper board, and pulping. The papermaking process requires a lot of energy, in the form of steam, to dry the paper web in rotating dryers. As steam condenses inside the dryers by releasing heat to the dryer walls, the condensate is removed using either stationary or rotary siphons. Since the condensate is usually at a saturated state, part of the condensate flashes into vapor during the extraction process and becomes difficult to extract. Thus, additional blow-through steam is used to push the condensate out. Since this blow-through steam is …

Mitigation Of Airborne Contaminant Spread Through Simple Interventions In An Occupied Single-Family Home, Florida Solar Energy Center, Nazim Muradov

FSEC Energy Research Center®

Historically, reducing aerosol-based transmission of respired viruses in indoor environments has been of importance for controlling influenza viruses and common-cold rhinoviruses. The present public health emergency associated with SARS-CoV-2 makes this topic critically important. Yet to be tested is the potential effectiveness of simple interventions that create an isolation zone (IZ) for a suspected/confirmed sick or sensitive person requiring quarantine. The intent in existing homes is to find a practical means to mitigate exposure to airborne contaminants. In creating an IZ in an occupied single-family home in the study, four simple strategies were tested. The test configurations were: (1) IZ …

Wildfire Prevention & Suppression System, Johnny Dimas Flores, Ansh Jetly, Antonio Lorenzo

Mechanical Engineering Senior Theses

The Bay area community has continually been at threat to wildfires. The current trend showed that wildfires would be an even more prevalent threat in the near future. Despite this, there still exists a lack of knowledge involving wildfire safety and protection for people’s property. Current systems were found to be too expensive, needed constant maintenance, or access to isolated storage of 1,000+ gallons of water. Through research of misting systems, the effectiveness of mist as a radiation shield, and working with members of CalFire, it was determined that the system needed to meet the following parameters to be effective …

Uavs For Vegetation Monitoring: Overview And Recent Scientific Contributions, Ana I. De Castro, Yeyin Shi, Joe Mari Maja, Jose M. Pena

Department of Mechanical and Materials Engineering: Faculty Publications

This paper reviewed a set of twenty-one original and innovative papers included in a special issue on UAVs for vegetation monitoring, which proposed new methods and techniques applied to diverse agricultural and forestry scenarios. Three general categories were considered: (1) sensors and vegetation indices used, (2) technological goals pursued, and (3) agroforestry applications. Some investigations focused on issues related to UAV flight operations, spatial resolution requirements, and computation and data analytics, while others studied the ability of UAVs for characterizing relevant vegetation features (mainly canopy cover and crop height) or for detecting different plant/crop stressors, such as nutrient content/deficiencies, water …

Three-Dimensional Shape Analysis Of Peripapillary Retinal Pigment Epithelium-Basement Membrane Layer Based On Oct Radial Images, Junfei Tong, Pengfei Dong, Sachin Kedar, Deepta Ghate, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The peripapillary retinal pigment epithelium-basement membrane (ppRPE/BM) layer angle was recently proposed as a potential index for estimating intracranial pressure noninvasively. However, the ppRPE/BM layer angle, measured from the optical coherence tomography (OCT) scans, varied across the radial directions of the optic disc. This made the ppRPE/BM layer angle difficult to be utilized in its full potential. In this study, we developed a mathematical model to quantify the ppRPE/BM layer angles across radial scans in relation to the ppRPE/BM 3D morphology in terms of its 3D angle and scanning tilt angles. Results showed that the variations of the ppRPE/BM layer …

A Self-Tunable Piezoelectric Energy Harvester, Ashraf Hussein

Theses and Dissertations

In this study, a new technique to harvest energy using inertial vibration energy harvesters is introduced. A triple-layer piezoelectric beam with a self-tunable frequency was developed in order to respond to variable-frequency excitations, thereby maintaining the beam in a state of resonance for maximum power output. The tuning mechanism managed to change the natural frequency of the beam in the range of 2.27 ���� to 6.25 ����. In this case, the output voltage could be raised from 12�� to 23��.

A mathematical model was developed to investigate the natural frequency, the output voltage, and the output power of the beam …

Frequency Domain Measurements Of Melt Pool Recoil Force Using Modal Analysis, Tristan Cullom, Cody Lough, Nicholas Altese, Douglas Bristow, Robert Landers, Ben Brown, Troy Hartwig, Andrew Barnard, Jason Blough, Kevin Johnson, Edward Kinzel

Michigan Tech Publications, Part 1

Recoil pressure is a critical factor affecting the melt pool dynamics during Laser Powder Bed Fusion (LPBF) processes. Recoil pressure depresses the melt pool. When the recoil pressure is low, thermal conduction and capillary forces may be inadequate to provide proper fusion between layers. However, excessive recoil pressure can produce a keyhole inside the melt pool, which is associated with gas porosity. Direct recoil pressure measurements are challenging because it is localized over an area proportionate to the laser spot size producing a force in the mN range. This paper reports a vibration-based approach to quantify the recoil force exerted …

Comparison Of Fish Assemblages Aggregated By Artificial Reefs Using Scuba Diving And Acoustic Surveys, Hsueh-Jung Lu, Jia-Rong Lin, Ting-Chieh Huang, Sunarti Sinaga

Journal of Marine Science and Technology–Taiwan

To determine the aggregation effect of artificial reefs (ARs), we conducted surveys in 16 artificial reefs in Taiwan by using the scientific echo sounder, Simrad EY-60 (200 KHz), along with sighting by scuba divers. Scuba diving was conducted within the reef structures (r ¼ 20 m), whereas acoustic surveys were conducted over a wider range (r ¼ 100 m), with five repeating transects over the ARs. We compared the results obtained from the two methods among 16 artificial reefs in the coastal waters of Taiwan to determine the consistency of the quantitative information between the two methods and to investigate …

Study On The Behavior Of Peled (Coregonus Peled ) Around A Set Net By Ultrasonic Biotelemetry System In A Plateau Lake, China, Jing Liu, Keiichi Uchida, Leiming Yin, Yong Tang, Yoshinori Miyamoto, Binbin Xing

Journal of Marine Science and Technology–Taiwan

Sayram Lake is a plateau cold-water lake located in northwestern China. Peled (Coregonus peled ) was introduced to Sayram Lake from Russia in 1998. The behavior characteristics of peled in Sayram Lake are important for fishery resource proliferation, effective fishing, and sustainable development. In this study, we used an ultrasonic biotelemetry system to track the fish around a large-scale set net in Sayram Lake. The purpose of this study is to study the behavior characteristics of the peled and to provide suggestions for the improvement of the set net. The results showed that the fish released in the playground of …

Energy-Based Orbital Stabilization Of Underactuated Systems Using Impulse Controlled Poincaré Maps, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of energy-based orbital stabilization of underactuated mechanical systems with one passive degree-of-freedom is addressed. The orbit is a manifold where the active generalized coordinates are fixed, and the total mechanical energy is equal to some desired value. A hybrid control strategy comprised of continuous and intermittent impulsive inputs is presented. The continuous controller is designed using partial feedback inearization to converge the active generalized coordinates to their desired values. The choice of desired energy characterizes a unique orbit which is stable but not asymptotically stable. To stabilize the desired orbit, a Poincaré section is constructed at a fixed …

Effects Of Air Pollution, Temperature And Moisture Content On Copper And Silver Corrosions And The Reliability Of Data Center Equipment, Rui Zhang

Dissertations - ALL

The effects of moisture content, temperature, and pollutant mixture on atmospheric corrosion of copper and silver were investigated by exposing test specimens to different environmental conditions, followed by surface characterization using the coulometric reduction, Scanning Electron Microscopy, and Energy Dispersive Spectrometry (SEM/EDS). Printed circuit board test cards (PCBs) with bare copper were also used to investigate the effects of voltage bias on the PCBs on the corrosion rate. The test specimens were exposed to mixed flowing gases (MFG) environment with eight different combinations of the following five pollutants at the fixed concentration levels: 60 ppb O3, 80 ppb NO2, 40 …

An Intelligent Virtual Design Studio (Vds) For Integrative Design Of Green Buildings, Zhaozhou Meng

Dissertations - ALL

The overall goal of the study was to develop a "Virtual Design Studio (VDS)": a software platform for integrated, coordinated and optimized design of green building systems with low energy consumption, high indoor environmental quality (IEQ), and high level of sustainability. My dissertation research was focused on the development of a key VDS component -- an integrated design process and a near-real time performance simulation approach for fast feedbacks at the early stage of the integrated design process.

A design process module "Magic Cube" (MC) was developed for the VDS as the core for the design integration and coordination. It …

Mash 2016 Test Level 3 And Test Level 4 Evaluation Of Roadside Safety Barrier With Pedestrian Features, Miguel Angel Hinojosa Palacios

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The Minnesota Department of Transportation (MnDOT) desires to use a vehicle, bicycle, and pedestrian combination bridge railing system along pedestrian and bicycle bridge paths. The system was evaluated per MASH 2016.

In full-scale crash test no. MNPD-3, the system was evaluated according to MASH test designation no. 3-11. The 2014 Dodge Ram 1500 crew cab pickup truck impacted the system 71¼ in. upstream from the centerline of post no. 4 with a speed of 63.4 mph at an angle of 25.3 degrees. The combination railing system was found to meet the AASHTO MASH 2016 TL-3 impact safety criteria.

MnDOT uses …

Seasonal Dynamics In Fish Distribution And Abundance Revealed By An Acoustic Survey In Coastal Waters Of The Suzu Area, Kochi Prefecture, Japan, Yanhui Zhu, Kenji Minami, Yuka Iwahara, Kentaro Oda, Koichi Hidaka, Osamu Hoson, Koji Morishita, Sentaro Tsuru, Masahito Hirota, Hokuto Shirakawa, Kazushi Miyashita

Journal of Marine Science and Technology–Taiwan

For Japan's fishery, it is essential to conduct sustainable and efficient fishery owing to the decline in fish catch as well as the fisher population. To obtain information that contributes to sustainable and efficient fishery, we researched appropriate set-net locations with regard to fish distribution, abundance, and environmental characteristics. We conducted surveys from 2017/5 to 2018/2 in the Suzu coastal area, Kochi Prefecture, where the only main industry is set-net fishery. We investigated the seasonal relationships between fish school characteristics, including distribution and size, and marine environmental conditions in the Suzu coastal area, using a quantitative echo sounder (KSE300 SONIC, …

Development Of A Biomass Assessment Method Using Fisheries Echo Sounder For Monitoring Whitebait Fishery In Shizuoka Prefecture, Japan, Kenichi Kobayashi, Yanhui Zhu, Daichi Oshiyama, Kenji Minami, Hokuto Shirakawa, Kazushi Miyashita

Journal of Marine Science and Technology–Taiwan

Coastal fisheries constitute the second most important sector in fishery production in Japan, following offshore fisheries. Thus, spatial evaluation of coastal fishing grounds and understanding of the changes in biomass are important for the sustainable use of fishing resources. For the assessment of spatial fish biomass, a quantitative echo sounder is used, but such a device is not mass produced and involves a high cost. In the present study, we examined the feasibility of biomass assessment using typical commercial fisheries echo sounders that are widely used and cheaper than quantitative echo sounders. Therefore, we aimed to verify the validity of …

An Intelligent Virtual Design Studio (Vds) For Integrative Design Of Green Buildings, Zhaozhou Meng

Dissertations - ALL

The overall goal of the study was to develop a “Virtual Design Studio (VDS)”: a software platform for integrated, coordinated and optimized design of green building systems with low energy consumption, high indoor environmental quality (IEQ), and high level of sustainability. My dissertation research was focused on the development of a key VDS component -- an integrated design process and a near-real time performance simulation approach for fast feedbacks at the early stage of the integrated design process.

A design process module “Magic Cube” (MC) was developed for the VDS as the core for the design integration and coordination. It …

Effects Of Air Pollution, Temperature And Moisture Content On Copper And Silver Corrosions And The Reliability Of Data Center Equipment, Rui Zhang

Dissertations - ALL

The effects of moisture content, temperature, and pollutant mixture on atmospheric corrosion of copper and silver were investigated by exposing test specimens to different environmental conditions, followed by surface characterization using the coulometric reduction, Scanning Electron Microscopy, and Energy Dispersive Spectrometry (SEM/EDS). Printed circuit board test cards (PCBs) with bare copper were also used to investigate the effects of voltage bias on the PCBs on the corrosion rate. The test specimens were exposed to mixed flowing gases (MFG) environment with eight different combinations of the following five pollutants at the fixed concentration levels: 60 ppb O3, 80 ppb NO2, 40 …

Acoustic Survey For Estimating Density Of Anchovy Schools In The South Sea Of Korea, Eunbi Min, Eun-A Yoon, Sung-Tae Kim, Seong Yong Moon, Hyun Woo Kim, Shelly Salim, Taejong Kang, Doo-Jin Hwang

Journal of Marine Science and Technology–Taiwan

No abstract provided.

Estimating The Sampling Efficiencies Of A Framed Midwater Trawl And Ring Net For Zooplankton Using An Acoustic Method, Zhen Lu, Tohru Mukai, Yasuzumi Fujimori, Kohji Iida

Journal of Marine Science and Technology–Taiwan

It is well known that there is bias using different sampling gear, such as a framed midwater trawl (FMT) and a ring net, when measuring the density and length distribution of target species. This limit is characterized by the sampling efficiency of the gear. Acoustic monitoring can be used to determine the sampling efficiencies of this gear, as its noninvasive, wide-range sweeps provide more reliable estimates of absolute abundance of the target species. The density measured by the gear can then be standardized by multiplying the initial density measurement by the derived sampling efficiency. In this study, we compared the …

In Situ Broadband Acoustic Measurements Of Age-0 Walleye Pollock And Pointhead Flounder In Funka Bay, Hokkaido, Japan, Kohei Hasegawa, Naizheng Yan, Tohru Mukai

Journal of Marine Science and Technology–Taiwan

Measurements of the broadband acoustic backscattering from fish should improve acoustic discrimination between species. The pulse compression processing of broadband systems can be used to measure acoustic backscattering with high range resolution and improve signal-to-noise ratio. This may increase opportunities for in situ target strength (TS) measurements, the preferred method of collecting TS data. To evaluate the availability of TS spectra for acoustic discrimination, three Simrad EK80 wideband transceivers and split-beam transducers of 70, 120, and 200 kHz were used to collect in situ frequency responses of TS from age-0 juvenile walleye pollock and pointhead flounder, a swimbladderless flat-fish, distributed …

Volume Scattering And Echo Integration In Fisheries Acoustics Revisited, Masahiko Furusawa

Journal of Marine Science and Technology–Taiwan

Echo integration is the most important method in fisheries acoustics. The basis of the method is volume scattering theory, and the theory assumes that many fish are randomly and homogeneously distributed broader than a beam spread. In actual acoustic surveys, however, we encounter various distributions for which these assumptions do not hold. It is the echo integration method that hypothetically fulfills these assumptions. In this paper, we review the volume scattering theory and the echo integration method historically and theoretically and confirm their bases. We then point out some misunderstandings affected by historical constraints such as the persistence of time …

Sound, Material And Strength Correlation, Ryan Mcbride

Symposium of Student Scholars

With a growing amount of manufacturing utilizing 3D printing, there is a correlation between strength and material which can affect sound produced by sirens. An air raid siren that has been downloaded from Thingiverse.com spins with a 49:1 gear ratio to produce 2 tone sounds and with that large number of revolutions comes friction, and in order to create a 3D printed air raid siren, the siren must be made out of a material that can withstand high temperatures without melting and quick rotations without delaminating. There are many materials that can be printed to withstand those forces, but it …

Classroom Room Acoustics And Effect On Speech With And Without Face Coverings In Direct And Reverberant Sound Fields, Danny Hernandez-Borjas

Symposium of Student Scholars

Prior to the COVID-19 pandemic, life consisted of seeing people in dense public areas such as malls, parks, and schools. But the life these people once knew has changed with face coverings becoming more prevalent in society along with social distancing which caused these public places to limit their capacity. However, a certain faction of society-this being students, have been affected immensely due to this transition of life at school which includes mandatory face coverings in the classroom and social distancing. This research focuses on the effects on speech with and without face coverings in a classroom setting in certain …

Real-Time Monitoring Of Fdm 3d Printer For Fault Detection Using Machine Learning: A Bibliometric Study, Vaibhav Kisan Kadam, Satish Kumar, Arunkumar Bongale

Library Philosophy and Practice (e-journal)

Additive Manufacturing has wide application range including healthcare, Fashion, Manufacturing, Prototypes, Tooling etc. AM techniques are subjected to various defects that may be printing defects or anomalies in machine. There is gap between current AM techniques and smart manufacturing since current AM lacks in build sensors necessary for process monitoring and fault detection. Both of these issues can be solved by incorporating real-time monitoring into AM. So the study is carried out to identify recent work done in AM to improve current system. For this bibliometric study Scopus database is used, study is kept limited to year 2010-2021 and English …

Open Source Vacuum Oven Design For Low-Temperature Drying: Performance Evaluation For Recycled Pet And Biomass, Benjamin R. Hubbard, Lindsay I. Putman, Stephen Techtmann, Joshua M. Pearce

Michigan Tech Publications, Part 1

Vacuum drying can dehydrate materials further than dry heat methods, while protecting sensitive materials from thermal degradation. Many industries have shifted to vacuum drying as cost-or time-saving measures. Small-scale vacuum drying, however, has been limited by the high costs of specialty scientific tools. To make vacuum drying more accessible, this study provides design and performance information for a small-scale open source vacuum oven, which can be fabricated from off-the-shelf and 3-D printed components. The oven is tested for drying speed and effectiveness on both waste plastic polyethylene terephthalate (PET) and a consortium of bacteria developed for bioprocessing of terephthalate wastes …

Mechanics Of Catheter Herniation, Chase Hartquist

McKelvey School of Engineering Graduate Student Theses & Dissertations

Endovascular catheter-based technologies have revolutionized the treatment of complex vascular pathology. Catheters and endovascular devices that can be maneuvered through tortuous arterial anatomy have enabled minimally invasive treatment in the peripheral arterial system. Although mechanical factors drive an interventionalist's choice of catheters and sheaths, these decisions are mostly qualitative and based on personal experience and procedural pattern recognition. The field currently lacks a definitive quantitative characterization of endovascular tools that are best suited for specific peripheral arterial beds. This approach gives rise to a phenomenon called catheter herniation, which occurs when a catheter is energetically displaced or buckles while a …

Numerical Simulation Of Flow Past An Airfoil With Ice Accretion On Leading Edge, Boyu Wang

McKelvey School of Engineering Graduate Student Theses & Dissertations

The focus of this research is on aerodynamic simulation of flow past NACA 23012 airfoil with clean surface and with ice accretion on its leading edge by using the commercial CFD solver ANSYS Fluent. Reynolds-Averaged Navier-Stokes (RANS) computations are performed using Spalart-Allmaras (SA) and Wray-Agarwal (WA) turbulence models. ANSYS mesh package ICEM is used to model the geometry and generate the mesh. The computations are performed at 0, 2, 4, 6, 8, 10, and 12 degrees angle of attack which are compared with experimental data. For the case of ice accretion at the leading edge, the physical geometry becomes more …

On The Comparison Of Flow Physics Between Minimal And Extended Flow Units In Turbulent Channels, Ethan A. Davis, Siamak Mirfendereski, Jae Sung Park

Department of Mechanical and Materials Engineering: Faculty Publications

Direct numerical simulations were performed to study the effects of the domain size of a minimal flow unit (MFU) and its inherent periodic boundary conditions on flow physics of a turbulent channel flow in a range of 200 ≤ Re_τ ≤ 1000. This was accomplished by comparing turbulent statistics with those computed in sub-domains (SD) of extended domain simulations. The dimensions of the MFU and SD were matched, and SD dynamics were set to minimize artificial periodicities. Streamwise and spanwise dimensions of healthy MFUs were found to increase linearly with Reynolds number. It was also found that both MFU …

Fatigue Monitoring Through Wearable Sensors For Construction Workers, Srikanth Sagar Bangaru

LSU Doctoral Dissertations

About 40% of the US construction workforce experiences high-level fatigue, which leads to poor judgment, increased risk of injuries, a decrease in productivity, and a lower quality of work. Excessive fatigue from working in unpleasant working conditions, long working hours, or heavy workloads can aggravate fatigue's adverse effects, leading to work-related musculoskeletal disorders (WMSDs) and productivity loss. Therefore, it is essential to monitor fatigue to reduce the adverse effects and preventing long-term health problems. However, since fatigue demonstrates itself in several complex processes, there is no single standard measurement method for fatigue detection. This research aims to develop a system …