Mechanical Engineering Commons^™

The Diffuse Bounce Back Lattice Boltzmann Method And Its Applications On The Study Of Fluid-Particle Interactions, Geng Liu

Dissertations and Theses

Fluid-structure interaction is very broadly seen and widely used in many industrial, engineering and environmental processes. The lattice Boltzmann method has been preferred for simulating particulate flows due to its advantages of easy implementation, micro- and mesoscopic physical insights and parallel algorithm. Both sharp and diffuse boundary treatments are studied to recover curved and moving boundaries on structured orthogonal grids for the lattice Boltzmann method. These methods can describe curved boundaries more accurately and more smoothly than the naive staircase approximation. However, to improve the order of velocity accuracy and to reduce the fluctuation of force, either interpolation or additional …

Transition To Turbulence And Relaminarization Of Pulsatile Pipe Flows, Joan Gomez

Dissertations and Theses

The instability and transition to turbulence and its evolution in pulsatile pipe flows involving both, reverse and no-reverse flows, is the primary focus of this experimental work. A piston driven by a programable DC servo motor was used to set up a water flow system and provide the pulsation characteristics. Time-resolved particle image velocimetry data were acquired in a refractive index matching setup by using a continuous wave laser and a high-frame-rate digital camera. The position of the piston was continuously recorded by a laser proximity sensor. Different experiments were carried out with Reynolds numbers in the range of 535 …

Simulation Of Particle Transport In A Multi-Component Flow With A High Viscosity Ratio Driven By Slender Structures, Michael Roeing-Donna

Graduate Research Theses & Dissertations

Simulating particle transport in multi-component fluid flows driven by slender structures is important but challenging, especially when dealing with large viscosity ratios. In this thesis, a general multi-physics model is introduced to handle multi-component fluid flows, slender beating structures, immersed particles/droplets, and their interactions. This multi-physics model has been validated with analytical solutions and other published experimental and numerical results for the mean mucous velocity. The validated model is used to study particle transport in nasal mucous layer, the interplay between cilia and fluid flow. The model shows that mucous-pericilairy layer interface and mucous-air interface remain a constant height throughout …

Modeling Study Of Electrocoagulation System For Treating Wastewater, Swachwa Dey

Graduate Research Theses & Dissertations

Effective treatment of wastewater from households, communities, and industries is vital to preserve our environment. Chemical treatment to add coagulants into the wastewater is the most popular treatment method, but due to the high operating cost and secondary contamination issue, a novel method to solve those issues is required. In this study, we revisited the electro-coagulation (EC) system which has promising features of low system/operating cost and environment friendly process. EC was actively developed once, but due to the low efficiency and scaling-up issues, it could not be fully utilized. In this study, physics-based mathematical model was developed to elucidate …

Assessing The Effectiveness Of Cfd To Solve An Inverse Problem Of Thermal Profiles For The Protodune-Sp Neutrino Detector, Cecilia Anne Streff

Electronic Theses and Dissertations

Computational fluid dynamics (CFD) is a branch of fluid mechanics which is employed to numerically solve complex fluid, heat transfer, and multiphysics problems. Traditionally, CFD techniques are used to solve “forward” problems—using some known information of a system as inputs to a representative model to predict experimental measurements or expected system behavior. The work presented here demonstrates how CFD may be used to solve an “inverse” problem—given limited experimental data and some model, predict (previously unidentified) “input” system (or system model) parameters. The case study for this research uses a validated CFD modeling approach of the liquid argon (LAr) region …

Morphology Control Of One-Dimensional Gallium Nitride Nanostructures By Modulating The Crystallinity Of Sacrificial Gallium Oxide Templates, Yun Taek Ko, Mijeong Park, Jingyeong Park, Jaeyun Moon, Yong Ho Choa, Young In Lee

Mechanical Engineering Faculty Research

In this study, we demonstrated a method of controllably synthesizing one-dimensional nanostructures having a dense or a hollow structure using fibrous sacrificial templates with tunable crystallinity. The fibrous ga2o3 templates were prepared by calcining the polymer/gallium precursor nanofiber synthesized by an electrospinning process, and their crystallinity was varied by controlling the calcination temperature from 500oC to 900oC. gaN nanostructures were transformed by nitriding the ga2o3 nanofibers using NH3 gas. All of the transformed gaN nanostructures maintained a one-dimensional structure well and exhibited a diameter of about 50 nm, but their morphology was clearly distinguished according to the crystallinity of the …

Direct Energy Deposition Of Mo Powder Prepared By Electrode Induction Melting Gas Atomization, Goo Won Roh, Eun Soo Park, Jaeyun Moon, Hojun Lee, Jongmin Byun

Mechanical Engineering Faculty Research

Molybdenum (Mo) is used to form a barrier layer for metal wiring in displays or semiconductor devices. Recently, researches have been continuously attempted to fabricate Mo sputtering targets through additive manufacturing. in this study, spherical Mo powders with an average particle size of about 37 um were manufactured by electrode induction melting gas atomization. Subsequently, Mo layer with a thickness of 0.25 mm was formed by direct energy deposition in which the scan speed was set as a variable. According to the change of the scan speed, pores or cracks were found in the Mo deposition layer. Mo layer deposited …

Effect Of Heat Treatment On Microstructure And Hardness Of A Worn Rail Repaired Using Laser Powder Deposition, Ershad Mortazavian, Zhiyong Wang, Hualiang Teng

Mechanical Engineering Faculty Research

The frequent replacement of worn rails on tracks brings an immense economic burden on the railroad industry, and also causes significant interruptions to railroad operation. Restoration of worn rails via laser powder deposition (LPD) can considerably reduce the associated maintenance costs. This study was focused on the use of LPD to repair the worn profile of a standard U.S. rail. The microstructure of the 304L stainless steel deposits with a minimum hardness of 85 HRB was composed of austenite, δ-ferrite, and sigma. Micropores were dispersed throughout the deposit, and microcracks were found at the rail-deposition interface. The pearlitic rail substrate …

Warm Unit Rod Movement Stand For Proton Improvement Project Ii, Christopher Shohei Becker

Graduate Research Theses & Dissertations

Fermilab is responsible for many experiments involving proton acceleration and requires a significant upgrade to its linear accelerator infrastructure to meet the needs of the 21st century high energy physics. The Proton Improvement Project II (PIP II) is a plan to allow Fermilab to maintain its title of most intense accelerator by doubling the output of its proton beam to 800 MeV. An array of high frequency cryomodules generate the beam but are limited in total manufacturing lengths. To connect the multiple devices, a combination of magnets and ion vacuum pumps at room temperature -- therefore called warm units -- …

Combined Puncture And Cutting Of Soft-Coated Fabrics By A Pointed Blade: Energy, Force, And Stress Failure Criteria, Ennouri Triki, Chantal Gauvin

Études primaires

Soft elastomer-coated fabrics are widely used in engineering and protective applications. Puncture cutting by sharp-tipped objects is one of the most common failure modes of protective gloves made of coated fabrics. In order to investigate the puncture-cutting process of soft elastomer-coated fabrics, we studied the mechanisms and mechanics of pointed-blade insertion into specimens cut out from four protective gloves. Experimental and analytical analyses showed that total energy and critical puncture-cutting force calculated analytically are both able to predict the puncture-cutting resistance of soft elastomer-coated fabrics measured experimentally. Total energy is obtained from the relationship between the puncture-cutting work and the …

Application Of Data And Geospatial Analysis In Energy And Health Systems, Ali Faghani

Graduate Research Theses & Dissertations

Having sustainable energy and health systems are the main factors in the vision plan of every country. Both of these systems are correlated with a variety of frameworks, including social, physical, technological, political, and economic factors. Therefore, different types of analytics methods can be implemented to develop the required assessments for those who make plans since understanding the effect of such factors individually, also their interactions, and the overall effect is crucial. With this regard, applications of data analysis and geospatial techniques in both energy, and health systems have recently gained attention. The proposed research here deployed advanced data analytics …

Thermal/Structural Analysis Of The Axion Quantum Metrology Cavity And Its Components, Tyler Funk

Graduate Research Theses & Dissertations

This research was centered around maximizing the capability to cool dielectric material within a containment unit, or Photonic Band Gap (PBG) cavity, designed for detecting axion dark matter and identifying the unit’s thermal properties. There are multiple types of PBG cavities, but the latest version that axion researchers wish to use has been theorized to contain possible issues related to its thermal properties. Thermal conductivity is an issue with the dielectric material because it is made from alumina which is highly insulative. This is important since the research is being done in a cryogenic environment and the thermal noise affects …

Microfluidics Design Considering Hyperuniformity And Cell Transport In Flow For Improved Circulating Tumor Cell Capture Efficiency, Michael Clarence Hood

Graduate Research Theses & Dissertations

Isolation of circulating tumor cells (CTCs) from patient derived blood samples for cancerdiagnostics and monitoring is challenging due to the extremely low CTC concentration. This thesis work evaluates the performance of passive microfluidics devices with different designs based on computational modeling. A new cell separation method is proposed based on velocity differentiation of varying cell sizes. All numerical studies were conducted in 2D based on a fluid structure interaction code where the fluid flow was solved based on the lattice Boltzmann method (LBM) implemented in Palabos, and the cell dynamics were simulated based on the molecular dynamics package LAMMPS, with …

Coaxially Electrospun Fibrous Polymer Scaffolds For Tissue Regeneration And Drug Delivery, Matthew Michael Kleszynski

Graduate Research Theses & Dissertations

A biomaterial is a substance that is specifically engineered to take on a role within the body, either alone or in conjunction with other materials, with the purpose of influencing the body. Using Polymers as a biomaterial is an exciting field of study that has the potential to further our abilities to help those in need. Creating composite nanofibrous scaffolds composed of hydrophobic and hydrophilic polymers may outperform structures made of a single polymer in both in vitro and in vivo environments. Hydrophilicity governs the behavior of polymers in the body and has influence over the mechanical properties of the …

Blood Flow Simulation In A Microvascular Network, Kacper Ostalowski

Graduate Research Theses & Dissertations

Cardiovascular disease such as heart attack or stroke has been the leading cause of death in the US for over 100 years. Understanding the blood cell transport physics in a vascular network is important in both fundamental research and clinical practices. In this study, 3Dnumerical simulations on blood flow in a complex retina vascular network were performed considering deformable red blood cells (RBCs), white blood cells (WBCs), and obstructed vessels. The blood was modeled as a mixture of RBCs and WBCs suspended in fluid. The fluid was solved using the lattice Boltzmann method (LBM), and blood cells were modeled by …

Developing A Standard Platform To Predict The Drag Coefficient Of Irregular Shape Particles, Amin Roostaeehosseinabadi

Graduate Research Theses & Dissertations

Solid-fluid interactions are commonly observed in natural transport phenomena and industrial applications such as sedimentation in rivers and pneumatic and hydraulic conveying of coarse particles. Here particle and fluid motion affect each other through force interactions, especially via drag force. To evaluate the magnitude of the drag force first the drag coefficient (CD) of the particle needs to be measured mostly experimentally. The CD depends on the particle’s geometry (i.e., shape, dimension, …) and the properties of the fluid medium. Since the solid particles commonly observed in nature or used in industrial setups come with irregular shapes, finding a relation …

A Dynamic Active Noise Control System For Live Music Attenuation, Elliot James Krueger

Graduate Research Theses & Dissertations

This thesis proposes a system design that will be suitable for applying active noise control (ANC) effectively to live musical instruments. The design consists of three parts: a signal separation section, an instrument classification section, and the active noise control section. The signal separation section will split up the music signals. The instrument classification section will identify the signals, and the ANC section will attenuate the music signal based on the previous information from the other sections. The two instruments of focus will be the trombone and tuba for their low frequency and ability to be quite loud in a …

Rebuild The Niu Split-Hopkinson Pressure Bar Apparatus For High Strain Rate Tensile Test, Dian Li

Graduate Research Theses & Dissertations

A Split-Hopkinson apparatus is a device used to dynamically test material properties for constructing constitutive model and can be used for high strain rate deformation research and experiments. NIU currently has a Split-Hopkinson apparatus that can conduct compressive tests only. The goal of this thesis is to redesign and rebuild the existing apparatus, so the high strain rate tensile tests can be conducted.

Multi-improvements were applied to the Split Hopkinson apparatus in order to improve its working performance. For conducting high strain rate tensile test, the Split-Hopkinson system has been rebuilt with a load-inversion device. The load-inversion device was designed …

A Theory-Supported Machine Learning Model For The Prediction Of Melt Pool Geometry And Optimal Process Window In Metal Additive Manufacturing, Sina Tayebati

Graduate Research Theses & Dissertations

Direct Energy Deposition (DED) is an additive manufacturing (AM) process capable of producing complicate-shaped or functionally graded components, and it is getting intense attention as a revolutionary technology to satisfy high demand in manufacturing process for the aerospace, automotive, and medical industries. However, the repeatability in geometries and properties of fabricated products is one of the most challenging issues for the DED process to be fully utilized, requiring comprehensive understanding of effect of processing conditions on the properties of fabricated parts, and development of relations among those conditions and properties. That is the motivation of this research. In this study, …

Performance And Economical Analysis Of Different Insulating Materials Used To Reduce The Heat Load Of An Existing Residential Building, Radwa A. El-Awadly, Ahmed A. Abdel-Rehim

Mechanical Engineering

The energy consumption from the residential sector is an important element which has an impact on the total energy consumption in any country. The heating and air conditioning loads can be reduced through many means. Using thermal insulation in buildings does not only contribute in reducing the required air conditioning system size, but also in reducing the annual energy cost for the whole building. In this case, the energy saving varies according to the building type, the climatic conditions at which the building is located as well as the type of the insulating material used. In the present study, an …

Effect Of Dust And High Temperature On Photovoltaics Performance In The New Capital Area, Engy Elshazly, Ahmed A. Abdel-Rehim, Amr Abdel Kader, Iman El-Mahallawi

Mechanical Engineering

The trend for integrating solar Photovoltaic Panels as an alternative renewable and sustainable energy source is growing in Egypt, North Africa and the Middle East. However, these efforts are not widely accepted by the society due to their lower efficiencies. The efficiency of the photovoltaic panels is affected by many environmental parameters, which have a negative impact on system efficiency and cost of energy, dust and increased panel temperatures being the most serious. This work presents the results of a case study conducted at The British University in Egypt at El-Sherouk city to study the effect of different parameters such …

An Experimental Study Of A Hemi-Spherical Solar Collector Under Egyptian Climate, Mohamed Ebaid, Salma Salah, Ahmed A. Abdel-Rehim

Mechanical Engineering

Traditional flat plate collectors have shown, under many investigations, low system operating efficiency, which prompted the idea of designing new solar collectors operating with higher efficiency. Such designs include spherical, hemi-spherical, cylindrical, or rhombic solar collectors. The current study experimentally investigates the performance of a stationary newly designed hemi-spherical solar collector in comparison with a flat plate solar collector with the same surface area and weather conditions. This target has been achieved through designing and manufacturing a hemi-spherical collector, followed by analyzing its performance under normal operating conditions of Egyptian climate. The Hemi-spherical solar collector showed a maximum efficiency of …

Energy And Exergy Analysis For Stationary Solar Collectors Using Nanofluids: A Review, Mahmoud Eltaweel, Ahmed A. Abdel-Rehim

Mechanical Engineering

Fossil fuels demonstrate pollution effects and significant emissions on the atmosphere, which made the use of clean, renewable sources of energy a necessity. Renewable energy has many sources, but the most promising and cheapest energy source is solar energy, which has led to a focus on efficient solar energy harvesting to be cheaper for public use. Stationary solar collectors like evacuated tube and flat-plate solar collectors are the most commonly used solar collectors for their simplicity of installation and maintenance. They are mostly used for domestic applications such as solar water heaters. Nanofluids can improve the thermal properties of the …

Numerical Investigation Of The Thermal Performance Of An Axially Rotating Internally Finned Receiver Tube Of A Parabolic Trough Concentrator, Andrew S. Tanious,, Ahmed A. Abdel-Rehim

Mechanical Engineering

Enhancement of the thermal performance of the parabolic trough receiver tube is one of the approaches to energy sustainability. In the present work, the thermal performance of an axially rotating receiver tube equipped with internal flat longitudinal fins is studied. The effects of both the fin height and the rate of axial rotation are investigated at low values of axial Reynold’s number. The numerical analysis is held at various rotation rates using ANSYS Fluent. The numerical findings showed that the effect of the axial rotation on the internally finned receiver tube is not significant yet negative where a maximum reduction …

Recent Advances In Preparation And Testing Methods Of Engine-Based Nanolubricants: A State-Of-The-Art Review, Sayed Akl, Sherif Elsoudy, Ahmed A. Abdel-Rehim, Serag Salem, Mark Ellis

Mechanical Engineering

Reducing power losses in engines is considered a key parameter of their efficiency improvement. Nanotechnology, as an interface technology, is considered one of the most promising strategies for this purpose. As a consumable liquid, researchers have studied nanolubricants through the last decade as potential engine oil. Nanolubricants were shown to cause a considerable reduction in the engine frictional and thermal losses, and fuel consumption as well. Despite that, numerous drawbacks regarding the quality of the processed nanolubricants were discerned. This includes the dispersion stability of these fluids and the lack of actual engine experiments. It has been shown that the …

Investigation Of The Tribological Behavior Of Mineral Lubricant Using Copper Oxide Nano Additives, Ahmed A. Abdel-Rehim, Sayed Akl, Sherif Elsoudy

Mechanical Engineering

In this study, tribological properties of custom formulated and stabilized nano lubricant are investigated. Spherical CuO nanoparticles are suspended in 20W-50 mineral base lubricant using Oleic Acid (OA) as a surfactant. Three different nano lubricant concentrations with 0.2, 0.5, and 1 wt.% were analyzed through ASTM G-99 pin-on-disc tribometer standardized test under boundary/mixed lubrication regimes. The generated friction and wear analyses confirm a consolidation of tribological properties with a reduction in friction coefficient in the range of 14.59–42.92%, compared with the base lubricant. Analysis of worn surfaces (SEM/EDX) as well as (AFM) was conducted. Combined hypotheses were proposed from the …

A Combined Study Of Heat Transfer And Temperature Distribution Inside Heated Double-Wall Infant Incubator Using Cfd, Hesham Safwat

Mechanical Engineering

What will be the answer if someone tried walking on the street and asking ten mothers in which pregnancy month their child had been born? The answer will be shocking because according to World Health organization (WHO 2012) at least one out of those ten mothers will answer that her kid was born earlier than his/her time! There are more than 15 million premature babies in the world having their first breath every year earlier than their times and more than 1.1 million of them the first few breaths unfortunately become their last. Moreover, if this question is asked to …

Cfd Investigation Of The Optimal Ventilation System For A Single-Family Room Neonatal Intensive Care Unit, Hesham Safwat, Ahmed Elbaz

Mechanical Engineering

Newborns are immunocompromised, and they are more susceptible to get infected than elders, hence, they should be kept in an aseptic environment that is almost free of microorganisms. A neonatal intensive care unit (NICU) is intended for caring for ill, premature and low-birth-weight infants. There are 2 main types of NICUs: the open-bay (OBA) NICU and single-family room (SFR) NICU. Researches have proved that the SFR NICUs have many advantages as compared with the OBA NICUs ,hence, SFR NICUs are predominant worldwide since 1994. The ventilation system has a crucial role in the infection prevention and control (IPC) program, as …

Effect Of Hearing And Head Protection On The Localization Of Tonal And Broadband Reverse Alarms, Chantal Laroche, Christian Giguère, Véronique Vaillancourt, Claudia Marleau, Marie-France Cadieux, Karina Laprise-Girard, Emily Gula, Véronique Carroll, Manuelle Bibeau, Hugues Nélisse

Études primaires

Objective

This study explored the effects of hearing protection devices (HPDs) and head protection on the ability of normal-hearing individuals to localize reverse alarms in background noise.

Background

Among factors potentially contributing to accidents involving heavy vehicles, reverse alarms can be difficult to localize in space, leading to errors in identifying the source of danger. Previous studies have shown that traditional tonal alarms are more difficult to localize than broadband alarms. In addition, HPDs and safety helmets may further impair localization.

Method

Standing in the middle of an array of eight loudspeakers, participants with and without HPDs (passive and level-dependent) …

Numerical Investigation Of The Earplug Contribution To The Low-Frequency Objective Occlusion Effect Induced By Bone-Conducted Stimulation, Kevin Carillo, Olivier Doutres, Franck Sgard

Études primaires

The use of earplugs is commonly associated with an increased perception of the bone-conducted part of one's own physiological noise. This phenomenon is referred to as occlusion effect and is most prominent at low frequencies. Several factors influence the occlusion effect, such as the ear anatomy; the bone-conducted stimulation; and the type of occlusion device and its fit, insertion depth, and material properties. The latter factor is of great interest to potentially reduce the occlusion effect of passive earplugs. This paper investigates the mechanism(s) of contribution of earplugs to the objective occlusion effect. A two-dimensional axi-symmetric finite element model of …