Mechanical Engineering Commons^™

Temperature Analysis Of A Square Lid-Driven Cavity With Particle Suspensions, Justin Kortge

Graduate Research Theses & Dissertations

Computational fluid dynamics (CFD) and discrete element method (DEM) are powerful tools for simulating systems that contain fluids and particles. Studies of particle fluid systems greatly vary in their applications and complexity, and yet there is a scarcity of studies focused on the thermal characteristics of the fluid. A computational analysis is conducted on two-dimensional flow in a square thermal lid-driven cavity to assess the effect of particle suspensions on the thermal characteristics of the cavity. Most studies analyzing the effect of suspensions in a thermal lid-driven cavity treat the medium as a single homogeneous nanofluid. Those that do treat …

Study Protocol To Analyze The Effects Of Posture And Exoskeleton On Human Exposure To Hand-Transmitted Vibration, Parisa Torkinejad Ziarati

Graduate Research Theses & Dissertations

Exposure to power hand tool-generated vibrations may lead to several health disorders collectively known as hand-arm vibration (HAV) syndromes. Power hand tools are often used in overhead postures in the manufacturing and construction industries. However, HAV risks are examined in the front-of-body posture in the existing safety standards and guidelines. Therefore, it is important to understand the effects of overhead working posture on vibration transmissibility (VT) in the upper extremities (UEs) and the spine. Secondly, there is a rising trend of using occupational exoskeletons (Exos) in the manufacturing and construction industries, especially involving overhead work with power hand tools. However, …

Process Optimization For An Integrated Reverse Osmosis—Pressure Retarded Osmosis Pilot-Scale System Operated On Humboldt Bay, Ca, Galen O'Toole

Cal Poly Humboldt theses and projects

Pressure retarded osmosis (PRO) is an emerging osmotic power technology that could mitigate the major challenges faced by seawater reverse osmosis desalination (RO): brine disposal and high energy consumption. The primary focus of this paper is process optimization for a linked seawater reverse osmosis (RO) and pressure retarded osmosis (PRO) water purification system. PRO generates power by using osmosis to “pump” water through a membrane from low pressure and low concentration to high pressure and high concentration (RO brine). This commercial-scale pilot effort explores process optimization for pressure retarded osmosis as an industrial process rather than theoretical or experimental process. …

Branched Chain Amino Acid Strain State Monitoring With Raman Spectroscopy And Plasmonic Bowtie Nanoantenna Devices For Early Disease Detection, Caroline A. Campbell

Theses and Dissertations

This work centers on the development and the down-selection of nano-manufactured devices to be used in conjunction with Raman spectroscopy for probing a branched chain amino acid. The nano-manufactured devices integrate plasmonic nanoantennas for the purpose of amplifying molecular fingerprints, which are otherwise difficult to detect, through Surface Enhanced Raman Spectroscopy (SERS). Plasmonic nanostructures can be utilized for a variety of biomedical and biochemical applications to detect the characteristic fingerprint provided by Raman Spectroscopy. The nano-manufactured devices create an electric field that amplifies minute perturbations and raises the signal above background noise. This may provide a deeper understanding of signal …

Development And Optimization Of A Low Volume Air-Jet Dry Powder Inhaler (Dpi) Platform For The Delivery Of High Dose Aerosolized Powder To Infants, Connor Howe

Theses and Dissertations

The goal of this research project was to develop an infant air-jet dry powder inhaler (DPI) platform for high-efficiency nose-to-lung (N2L) aerosol administration to infants through optimization of individual system components followed by expansion of the system to higher doses and different formulations using a new approach. Primary challenges associated with aerosol delivery to infants using the N2L route include the extremely narrow extrathoracic airways, short inspiratory times (~0.2 sec), low safe airway pressure (H₂O), and very low volumes of air (~10 mL) available to form the aerosol. The infant air-jet DPI system was comprised of three main …

Workforce Development Strategies In Additive Manufacturing, Mel Cossette, Ismail Fidan, Gaffar Gailani, Angran Xiao

Publications and Research

Additive Manufacturing (AM), also known as 3D Printing (3DP), is one of the newest manufacturing technologies with growing utilization in our daily life. Parallel to this growth, new materials, machines, and specific processes are being developed to produce parts in better-finished quality, at lower cost, and with shorter production time. However, workforce education in this evolving field has not advanced at the same pace as the technology, lacking proven curriculums, high-quality/accredited degree programs, and specialized advanced degrees. In this paper, some best practices established by the authors are introduced. The list is far from exhaustive but is proven to be …

Cool Thermal Energy Storage: Water And Ice To Alternative Phase Change Materials, Sandra K. S. Boetcher

Publications

Cool thermal energy storage has a long history dating back to ancient times with modern developments beginning in the mid-nineteenth century where blocks of ice were cut from frozen lakes for cooling applications. Today, the prevalent mode of thermal energy storage is the utilization of ice tanks in commercial buildings for peak shaving and load shifting. In this chapter, a summary of different types of water/ice thermal energy storage systems is provided; an overview of alternative phase change materials for use in cool thermal energy storage is given; and alternative phase change material thermal energy systems, their implementation, challenges, and …

A General Coupling Methodology For Unsteady Aerostructural Optimization With Analytic Derivatives, Taylor Mcdonnell, Adam Cardoza, Denis-Gabriel Caprace, Andrew Ning

Faculty Publications

Multidisciplinary design optimization offers a comprehensive approach for designing complex aerostructural systems such as wind turbines. Gradient-based multidisciplinary design optimization can be used to optimize complex systems using large numbers of design variables. However, the convergence of gradient-based optimization methods to an optimal solution is highly dependent on the accuracy of the provided derivatives. In this paper, we propose a general method for creating unsteady coupled systems for steady-state, eigenvalue, and time-domain analyses. We then describe how highly accurate derivatives may be obtained from these analyses using a combination of automatic differentiation and analytic methods (including the unsteady adjoint). Finally, …

In-Flow Dynamics Of An Area-Difference-Energy Spring-Particle Red Blood Cell Model On Non-Uniform Grids, Brendan Walsh, Fergal Boyle

Articles

In this paper the area-difference-energy spring-particle (ADE-SP) red blood cell (RBC) structural model developed by Chen and Boyle is coupled with a lattice Boltzmann flux solver to simulate RBC dynamics. The novel ADE-SP model accounts for bending resistance due to the membrane area difference of RBCs while the lattice Boltzmann flux solver offers reduced computational runtimes through GPU parallelisation and enabling the employment of non-uniform meshes. This coupled model is used to simulate RBC dynamics and predictions are compared with existing experimental measurements. The simulations successfully predict tumbling, tank-treading, swinging and intermittent behaviour of an RBC in shear flow, and …

Tidal Current Turbine Blade Optimisation With Improved Blade Element Momentum Theory And A Non-Dominated Sorting Genetic Algorithm, Eng Jet Yeo, David Kennedy, Fergal O'Rourke

Articles

Tidal current energy has the advantage of predictability over most of the other renewable energy resources. However, due to the harsh operating environment and complicated site conditions, developments in this domain have been gradual. Paramount to these points is device design and optimisation of hydrodynamic performance. Recent developments in the correction models of BEM theory have further improved the accuracy of the prediction model. Using an improved blade element momentum theory model that is capable of accurately capturing the downwash angle and combining it with a well-developed and reliable non-dominated sorting genetic algorithm model, an effective and efficient tidal current …

Building Performance - Societal Drive, Programme And Symposium, Joseph Little, Patrick Daly

Articles

Society is increasingly looking at the construction industry to mitigate the environmental crisis and solve the housing crisis through wholesale embrace of three broad sets of challenges. The MSc in Building Performance (Energy Efficiency in Design) (MSc BP(EED)) was created in 2017 to provide significant upskilling in the knowledge, skills, and software applications of building design professionals so that they can meet these challenges, while creating compliant, sustainable, super-low energy, new and renovated buildings. The delivery of the programme supports upskilling of employed building design professionals at Masters level, encouraging a minority to develop their capacity and interest in research …

Determining Cause Of Failure For Load Cells Supporting Vertical Pressure Vessels Subject To Wind Loading, Seth Nowak

College of Graduate Studies: Theses & Dissertations

Wind loads cannot be avoided during a natural disaster such as a hurricane and could affect the strength and stability of vertical pressure vessels during exposure. Vertical pressure vessels cater to large wind loads; therefore, it is imperative to study the effect of additional loading on the structures. In this study, three pressure vessels with volumes of 50 CuFt, 200 CuFt, and 1100 CuFt, supported by three equidistant load cells under their legs are individually analyzed to determine von mises stress to estimate yield failure criteria. Two load rating criteria, maximum load capacity and water-filled condition (critical condition) are utilized …

Plasma Spheroidization Of Gas-Atomized 304l Stainless Steel Powder For Laser Powder Bed Fusion Process, M. Hossein Sehhat, Austin T. Sutton, Chia-Hung Hung, Ben Brown, Ronald J. O'Malley, Jonghyun Park, Ming-Chuan Leu

PSMRC Faculty Research

Particles of AISI 304L stainless steel powder were spheroidized by the induction plasma spheroidization process (TekSphero-15 spheroidization system) to assess the effects of the spheroidization process on powder and part properties. The morphology of both as-received and spheroidized powders was characterized by measuring particle size and shape distribution. The chemistry of powders was studied using inductively coupled plasma optical emission spectroscopy for evaluation of composing elements, and the powder’s microstructure was assessed by X-ray diffraction for phase identification and by electron backscattered diffraction patterns for crystallography characterization. The Revolution Powder Analyzer was used to quantify powder flowability. The mechanical properties …

Coastal Wave Powered Reverse Osmosis System, Alexander Raymond Charest, Joeseph Daniel Camobreco, Tori Sweet, Sam Williams, Andrew Lepage, Devan Sack, Meagan Wiggin, Chelsea Kimball, Brendan Reagan

Honors Theses and Capstones

Part of the Marine Energy Collegiate Competition (MECC) is the optional Build and Test Challenge where teams are encouraged to build a portion of their proposed solution. After the conducted testing the laboratory results are compared to the simulated and calculated models. For the MECC the University of New Hampshire (UNH) team decided to use a wave energy converter to produce pressurized water. The pressurized water would be filtered through a reverse osmosis membrane to make it potable. Our system uses the power of the ocean waves to move a float up and down in heave motion. This motion drives …

Am Surface Roughness And Its Impact On Drag, Jackson Landry Chandler

Honors Academy

“The main goal of this thesis is to quantify additive manufacturing (AM) surface roughness, as a precursor to identifying its impact on unsteady transient flow properties. Experimental data using the Hirox optical microscopes and SEM imaging collected from the nylon and stainless-steel lattice structures contained an inherent level of surface roughness at the finer scale. Surface Roughness have a negative effect on additively manufactured materials and as such should be mitigated whenever possible. Surface roughness increases unwanted features such as the level of drag, skin friction, negative heat transfer/mass transfer properties, and other unwanted unsteady transitional flow characteristics. Though exceptions …

Fuel Cell Having Corrugated Membrane Electrode Assembly, Jonghyun Park

Patents

An electrochemical reaction cell comprising an anode electrode, a cathode electrode, and a membrane electrode assembly (MEA). The MEA is positioned between the anode electrode and the cathode electrode. The anode electrode, the cathode electrode, and the MEA each have a corrugated shape and are contained within a recess of a housing.

Distributed Process State And Input Estimation For Heterogeneous Active/Passive Sensor Networks, Dzung Minh Duc Tran, Tansel Yucelen, Selahattin Burak Sarsilmaz

Patents

Systems and methods are described for estimating a state of a process and an input to the process using a sensor network. Each sensor node in the sensor network is directly to one or more adjacent sensor nodes and indirectly coupled to the remaining sensor nodes through the one or more adjacent sensor nodes. Each sensor node iteratively calculates a new estimated state based on estimations of the state and the input to the process calculated by the sensor node in a previous iteration. The new estimated state is then adjusted based on a difference between a predicted and actual …

A Study Of Reduced Activation Ferritic Martensitic Metal Core Wire For Wire Arc Additive Manufacturing, Alexander L. Reichenbach

College of Graduate Studies: Theses & Dissertations

This study seeks to determine the technical feasibility of fabricating reduced activation ferritic martensitic (RAFM) steel parts, using a wire arc additive manufacturing (WAAM) process. The WAAM process, manufactures a part by depositing layers of metal onto a substrate to build a large scale near net shape part. RAFM alloy steels are next generation steels designed to resist radiation effects in the radiation intense working environments, such as nuclear reactors. To achieve this, process development and testing to design the WAAM production process with the custom RAFM filler wire was carried out. Several welding waveform modes were tested, and it …

Effects Of Titanium And Cerium Addition On Grain Size And Mechanical Properties Of Ductile Iron Castings, Shelton F. Fowler Iv

College of Graduate Studies: Theses & Dissertations

According to the Hall-Petch equation, the refinement of grains in metals increases the yield strength of the material. Austenite grain size influences the fineness of microstructural constituents in the ferrous alloys. It is well studied that cerium and titanium refine the austenite in steels and some gray irons, but no studies have been done to systematically explore the effects of cerium and titanium additions on austenite in ductile iron. This study sought to determine the effects of selected levels of these elements on the grain size within ductile iron. A hypoeutectic iron was chosen for testing as the proeutectic phase …

Cfd And Heat Transfer Analysis Of Rocket Cooling Techniques On An Aerospike Nozzle, Geoffrey Sullivan

College of Graduate Studies: Theses & Dissertations

In recent years the development of rocket engines has been mainly focused on improving the engine cycle and creating new fuels. Rocket nozzle design has not been changed since the late 1960s. Recent needs for reliable and reusable rockets, as well as advancements in additive manufacturing, have brought new interest into the aerospike nozzle concept. This nozzle is a type of altitude adjusting nozzle that is up to 90% more efficient than bell nozzles at low altitudes and spends up to 30% less fuel. Since the nozzle body is submerged in the hot exhaust gasses it is difficult to keep …

Numerical Design Of Steerable Guidewires, Onkar Prakash Salunkhe

Dissertations, Master's Theses and Master's Reports

Biomedical devices are an integral part of the medical industry nowadays. With the increase in cases of heart disease, catheterization procedures are becoming more frequent. Small-scale actuators are needed for the guidance of small-scale catheters and guidewires to remote targets in the human body. Numerical modelling is needed to guide the experiments in developing such steerable devices and to optimize their design. Here, we designed small-scale steerable guidewires by first developing bending actuators and then assembling them with guidewires. The actuators use materials with strain response to electric potential in a very low voltage range that is not harmful to …

Wireless Power Transfer In Autonomous Mobile Microgrids, Carl Greene

Dissertations, Master's Theses and Master's Reports

The ability to autonomously dock unmanned ground vehicles plays a key role in mobile micro-grids, where efficient power transfer is paramount. The approach utilized in this work allows for near-field wireless power transfer in remote locations with minimal support. Establishing a micro-grid power system connection autonomously using wireless power eliminates the arduous task of designing a complex, multiple degrees of freedom (MDOF) robotic arm. The work presented in this thesis focuses on both the hardware and software within the micro-grid system. This particular near-field wireless system consists of a primary and secondary set of modules, comprised of Litz wire coils, …

Development And Validation Of A Force Measuring Device For A Laboratory Wave Tank, Jacob K. Colling

Dissertations, Master's Theses and Master's Reports

The ability to predict the hydrodynamic force exerted on floating bodies plays a critical role in creating more effective control strategies for wave energy converters (WECs). Developing a test apparatus capable of directly measuring the forces exerted on a floating body subjected to a wavefield provides the means to validate theoretical prediction methods with experimental results and to develop data-based prediction methods for hydrodynamic forces. This report will discuss the development and validation of a device that measures the total vertical force exerted on a test artifact. The device requirements and design are discussed to examine the factors taken into …

Passivity-Based Numerical Modeling And Grid Integration Strategies For Wave Energy Converter Arrays, Salman Husain

Dissertations, Master's Theses and Master's Reports

The body of work presented here develops numerical time-domain models of Wave Energy Converter (WEC) arrays or wave farms. It will be shown here that a cluster of WECs can be more effective in extracting oceanic energy, can facilitate deployment logistics, and help with grid integration. The objectives of this work are: (i) developing a theoretical metric to evaluate the energy extraction potential of a WEC array, (ii) developing an algorithm that ensures the stability of the time-domain models of WEC arrays, and (iii) identifying strategies that facilitate grid integration and power management of a WEC array. In the process …

An Experimental Study Of Fuel Selection For A Gasoline Multi-Mode, Spark Ignited – Compression Ignition Engine, Zachary J. Stanchina

Dissertations, Master's Theses and Master's Reports

In this study of fuels of different reactivities and their performance in a low-temperature combustion (LTC) engine. The engine was a 2.2L CRDI engine code D4HB provided by industry partner Hyundai America Technical Center inc. (HATCI). The engine was instrumented with in-cylinder pressure sensors allowing for monitoring of the combustion process.

First, the engine was operated with standard US pump grade gasoline, Research Octane number (RON) 91 E10, to find initial operation conditions as well as control points of stable operation for daily checks on system conditions.

Tested were 8 different fuel blends, the four base blends were provided by …

Atomistic-Continuum Membrane And Machine Learning Models For Two-Dimensional Materials, Upenda Yadav

Dissertations, Master's Theses and Master's Reports

“What could we do with layered structures with just the right layers?” asked Richard Feynman in his famous 1959 lecture, “There’s plenty of room at the bottom.” With the help of the amazing developments of the past several years, we are coming close to answering that question. In 2004, graphene was first isolated from graphite and only six short years later it won the Nobel Prize in Physics. Graphene is one atomic layer of Carbon, it is the thinnest and yet the strongest materials we have ever seen. It is 200 times stronger than its equivalent weight in steel and …

Permeability, Structural Changes, Flow Regime Transitions In Fuel Cell Catalyst Layers And A Model For Predicting Trapped Saturation For Two-Phase Flow In Porous Media, Karrar Takleef Alofari

Dissertations, Master's Theses and Master's Reports

Proper water management in Proton Exchange Membrane (PEM) fuel cell is important to achieve high performance. Understanding the percolation of the produced water at the cathode catalyst layer (CL) is critical for any robust water management technique. In this study, an ex-situ experimental setup is used to study percolation in the CL at different injection rates and relative humidity (RH) conditions. The results show that increasing the flow rate force the liquid to flow through the bulk of the pores due to the dominant viscous effect. On the other hand, at low injection rates, the capillary becomes dominant and liquid …

Partially Stratified Combustion Of Natural Gas For Spark Ignition Engines, Philip S. Zoldak

Dissertations, Master's Theses and Master's Reports

In this work, the advantages of partially stratified direct injection natural gas versus premixed port-fueled injection natural gas spark ignited engines has been studied. The volumetric efficiency, ratio of specific heats and turbulent kinetic energy was found to be higher with direct injection versus port-fueled injection thus improving thermal efficiency. A background study of optical chamber experimental data was performed to develop an understanding on the effect of pressure ratio on direct injection of methane under both fully-expanded (sub-sonic) and under-expanded (super-sonic) conditions. Under-expanded jets had a noticeable advantage in terms of turbulent kinetic energy, which led to enhanced air …

Optimal Control Of Nonlinear Wave Energy Converters In Heave For Maximum Power Extraction, Kevin Nelson

Dissertations, Master's Theses and Master's Reports

The marine renewable energy community is interested in maximizing the power generated by nonlinear wave energy converters. Optimal control methods provide a tool to achieve this aim and can also help to inform the buoy design. An energy-optimal control law for a class of non-linear buoy models is derived and is shown to be singular. The solution approach is illustrated using an hourglass-shaped buoy having a cubic, hydrostatic nonlinearity. The optimal control law is only valid on singular arcs, and a method to search for these arcs is presented. Two singular arcs are found for the hourglass buoy model and …

Concept Evaluation And Development Of A Novel Approach For Integration Of Turbogeneration, Electrification And Supercharging On Heavy Duty Engines, Satyum Joshi

Dissertations, Master's Theses and Master's Reports

While many technologies such as electrically assisted turbocharging, exhaust energy recovery and mild hybridization have already proven to significantly increase heavy-duty engine efficiency, the key challenge to their widespread adoption has been their cost effectiveness and packaging. This research specifically addresses these challenges through evaluation and development of a novel technology concept termed as the Integrated Turbogeneration, Electrification and Supercharging (ITES) system. The concept integrates a secondary compressor, a turbocompound/expander turbine and an electric motor through a planetary gearset into the engine cranktrain. The approach enables a reduced system cost and space-claim, while maximizing the efficiency benefits of independent technologies. …