Mechanical Engineering Commons^™

Development And Experimental Study Of A Novel Plate Dehumidifier Made Of Anodized Aluminum., Tao Wen, Lin Lu, Chuanshuai Dong, Yimo Luo

Faculty of Science & Technology (THEi)

The falling film dehumidifier is a key component in the liquid desiccant cooling system (LDCS). However, the most commonly used metals, such as steel and aluminum, can hardly resist the erosion of liquid desiccant. It greatly limits the fabrication of compact dehumidifiers and hinders the promotion of LDCS. The present study introduced a novel falling film dehumidifier which was made by the metal of anodized aluminum. Experiments were carried out to compare the dehumidification performance between ordinary aluminum dehumidifier and anodized one. The influences of air temperature, mass flow rate, inlet humidity and solution temperature, mass flow rate, temperature on …

Visible Light Crosslinkable Human Hair Keratin Hydrogels, Kan Yue, Yanhui Liu, Batzaya Byambaa, Vaishali Singh, Wanjun Liu, Xiuyu Li, Yunxia Sun, Yu Shrike Zhang, Ali Tamayol, Peihua Zhang, Kee Woei Ng, Nasim Annabi, Ali Khademhosseini

Department of Mechanical and Materials Engineering: Faculty Publications

Keratins extracted from human hair have emerged as a promising biomaterial for various biomedical applications, partly due to their wide availability, low cost, minimal immune response, and the potential to engineer autologous tissue constructs. However, the fabrication of keratin-based scaffolds typically relies on limited crosslinking mechanisms, such as via physical interactions or disulfide bond formation, which are time-consuming and result in relatively poor mechanical strength and stability. Here, we report the preparation of photocrosslinkable keratin-polyethylene glycol (PEG) hydrogels via the thiol-norbornene “click” reaction, which can be formed within one minute upon irradiation of visible light. The resulting keratin-PEG hydrogels showed …

Performance Trades For Multiantenna Gnss Multisensor Attitude Determination Systems, Nathan A. Tehrani, Jason N. Gross

Faculty & Staff Scholarship

We present various performance trades for multiantenna global navigation satellite system (GNSS) multisensor attitude estimation systems. In particular, attitude estimation performance sensitivity to various error sources and system configurations is assessed. This study is motivated by the need for system designers, scientists, and engineers of airborne astronomical and remote sensing platforms to better determine which system configuration is most suitable for their specific application. In order to assess performance trade-offs, the attitude estimation performance of various approaches is tested using a simulation that is based on a stratospheric balloon platform. For GNSS errors, attention is focused on multipath, receiver measurement …

Further Development Of A Thermal Comfort Based Fuzzy Logic Controller For A Direct Expansion Air Conditioning System, Huaxia Yan, Yan Pan, Zhao Li, Shiming Deng

Faculty of Science & Technology (THEi)

The primary purpose of A/C is offering occupants with acceptable indoor thermal comfort levels. Thermal comfort is a complicated result of non-linear interactions between six parameters. However, many of current A/C systems solely control air temperature. Whenever anyone of the five parameters other than temperature varies significantly, an occupant may feel thermally uncomfortable. To address the issue, a comprehensive thermal comfort index should be used as regulator in A/C systems. One fuzzy logic controller is available. However, the approach to the fuzzy logic controller is complicated. In this paper, one previous established fuzzy logic controller is simplified for its real …

Exercise Machine Generator, Duane Harbick

All Undergraduate Projects

Exercise “spinning bikes” and bicycle training stands are common ways to maintain fitness and train for cycling. This exercise necessitates the user putting work into the machine by means of pedaling. In many instances the work put into exercise bikes and training stands is not taken advantage of. The objective of this project is an attempt to make use of some of the energy that a person would usually expend during exercise by building a generator that interfaces with multiple spinning bikes and training stands. It uses a synchronous pulley system to interface with the exercise machine and spin a …

Asme Rc Baja Challenge: Suspension And Steering, Hunter W. Jacobson

All Undergraduate Projects

The American Society of Mechanical Engineers (ASME) usually hosts an RC Baja challenge each year, testing a RC car in three events: slalom, acceleration and Baja. Although ASME will not be holding an event this year, CWU will be holding a similar event with three RC Baja car teams from CWU. The RC car that is tested in these events is designed and manufactured typically in teams of two. The RC car that each team submits must be able to complete these events while also remaining competitive. One part of great importance for the RC car is the suspension and …

Easy Install Outboard Motor Mount, Doug Dunbar

All Undergraduate Projects

The boating industry can be expensive for the typical weekend boater. That is, keeping, maintaining, and using a boat and all of its various accessories is a constant cost for the owner. In the Midwest and inland it is necessary to store boats and outboard boat motors out of the inclement weather and harsh conditions of seasonal change. Specifically, removing or installing an expensive and awkward outboard motor can be both dangerous financially and physically (damage or injury). It is not uncommon for motors to cost several thousand dollars.

The purpose of this project was to research, design, and implement …

Cwu Bottle Opener Manufacturing, Austin Sanford

All Undergraduate Projects

Previous students from the Mechanical Engineering Technology program came up with a method to help raise funds and awareness for the program. The idea was to manufacture and sell CWU bottle openers. However, a more efficient manufacturing method was needed. The aspect of the process that would have the most impact on the manufacturing time and material efficiency was the CNC machining of the parts. There were many potential variables to change to improve the process, but the main changes were to the cutter speeds and stock material size. Consequently, the changes made to stock material size reduced the number …

Asme R/C Baja Car, Torrie Large

All Undergraduate Projects

How does one build a car? Do they start with the tires and build inward or do they develop separate aspects at the same time? This remote-controlled car was designed and built with the intention of competing in the annual Baja Competition. There are three competitions: sprinting, slalom, and an obstacle course. The suspension system of this car must be designed to support the car for both the physical build and the competitiveness. It must do this without interfering with the drive train and steering mechanism designed by Doug Erickson. The suspension system employs suspension arms attached to the chassis …

Seawater Distiller (Solar Collector For Heating Seawater), Ali Alismail

All Undergraduate Projects

Many people in the world globally have limited or no access to clean drinking water. Unclean drinking water is a major cause of deadly diseases such as typhoid, cholera, and other water-borne diseases. The motivation of this report aims to document a senior project to satisfy for the award of MET by CWU. The aim was to design and manufacture a solar thermal collector capable of heating water using solar energy. The solar collector was developed by designing and fabricating a parabolic reflective surface. The reflective surface was manufactured from a reflective stainless-steel sheet. The advantages of using a parabolic …

Cassette Lockring Removal Tool, Kyle Wright

All Undergraduate Projects

Removal of a bicycle cassette requires additional tools to hold the cassette in place while loosening the cassette lockring. Typically a tool called a chain whip is used to stabilize the cassette, but is difficult to quickly and correctly apply to the cassette. Due to the need for an additional tool to hold the cassette, the user is faced with utilizing both hands while still needing to somehow hold the wheel in place. The lockring is torqued relatively tight and the overall combination of force, ergonomics, and number of tools required makes the task difficult to perform quickly. The objective …

H.F. Hauff Pruner Cutting Blades, Wyley Stewart

All Undergraduate Projects

Apple orchards are a critical component of agriculture in the United States, and keeping the apple trees in the best shape for optimum growth and production is hard work. Neil Hauff, an agriculture industry expert, challenged students at CWU to engineer a power assisted tree pruner. Across the country, apple orchards need pruned every season. The pruning of the trees is strenuous manual labor that requires many man hours. The proposed solution is to create a power assisted tree pruner that would minimize the amount of work needed to trim each tree branch. This project has been separated into three …

Mechanical Properties Of The Skeleton Of Acropora Cervicornis, Bridget Masa

Honors Undergraduate Theses

This research explores the instantaneous mechanical behavior of the skeleton of the critically endangered staghorn coral Acropora cervicornis. Both bleached and sanded skeletons were used in this experiment. The Raman spectroscopy test showed that there was no significant change in the Raman shift between the three branches tested. The shifts were nearly identical to Raman shifts of calcium carbonate. Vickers hardness test found that 1 Bleached had the average hardness of 3.44 GPa with a standard deviation of 0.12 GPa. The sanded sample also had a similar value of 3.54 GPa with a standard deviation of 0.13 GPa. Samples from …

Electrostatic Potential And Valence Modulation In La0.7sr0.3mno3 Thin Films, Robbyn Trappen, A. C. Garcia- Castro, Vu Thanh Tra, Chih-Yeh Huang, Wilfredo Ibarra-Hernandez, James Fitch, Sobhit Singh, Jingling Zhou, Guerau Cabrera, Ying-Hao Chu, James M. Lebeau, Aldo H. Romero, Mikel B. Holcomb

Faculty & Staff Scholarship

The Mn valence in thin film La0.7Sr0.3MnO3 was studied as a function of film thickness in the range of 1–16 unit cells with a combination of non-destructive bulk and surface sensitive X-ray absorption spectroscopy techniques. Using a layer-by-layer valence model, it was found that while the bulk averaged valence hovers around its expected value of 3.3, a significant deviation occurs within several unit cells of the surface and interface. These results were supported by first principles calculations. The surface valence increases to up to Mn3.7+, whereas the interface valence reduces down to Mn2.5+. The change in valence from the expected …

Enhancement Of Performance Of Micro Direct Ethanol Fuel Cells By Structural Modification, Sindhuja Valluri

Masters Theses

“Direct Ethanol Fuel Cells (DEFC’s) are becoming more important in current energy conversion devices because of their higher efficiency compared to other fuel cells. However, the performance of current DEFC’s is not efficient in providing energy to meet increasing energy demand. The objective of this work is to make the cell compact and at the same time improve performance. For this purpose, we have removed gasket and endplates to make structure compact and increased surface area by developing a new corrugated structure. This work also uses 3D printing technology Fused Deposition Modeling (FDM) to make pocket backing case to improve …

Soy-Based Polyurethane Foam For Insulation And Structural Applications, Gurjot S. Dhaliwal

Doctoral Dissertations

"Polyurethane (PU) foams are widely used as insulation materials due to their high insulation properties and low cost compared to conventional materials such as styrene and mineral wool. PU foams are traditionally fabricated with petroleum-based precursors. However, high crude price and higher carbon footprint has lead interest of researchers to synthesis PU foams using plant-based raw materials, that are inexpensive and renewable. In this dissertation, PU foams were fabricated using soy-based polyol and its thermal and mechanical properties were investigated. In the first part, of PU foam samples with different formulations were fabricated using soy-based polyol HB230, and varying amounts …

Pressure Image Based Attitude Controller For Small Unmanned Aerial Vehicles, Kenneth Thompson

Electronic Theses and Dissertations

As technology improves, small unmanned aerial vehicles (SUAV) have been identified for their utility in a variety of applications in which larger unmanned craft may be incapable of accomplishing mission objectives. These aircraft with their small size and long flight durations are ideal for hazardous inspection and long duration surveillance missions. One challenge preventing the widespread adoption of these systems is their instability to abrupt changes in the flow field around them due to wind gusts or flow separation. Currently, traditional rigid body based sensors are implemented in their flight control systems, which are sufficient in higher inertia aircraft for …

A Modeling Framework Of Brittle And Ductile Fractures Coexistence In Composites, Yangyang Qiao

Electronic Theses and Dissertations

In order to reduce the weight of automobiles and aircrafts, lightweight materials, such as aluminum alloy, advanced high strength steel, composite materials, are widely used to replace the traditional materials like mild steel. Composite materials are complicated in material mechanical properties and less investigated compared to metallic materials. Engineering composites can be categorized into polymer matrix composites (PMCs), metal matrix composites (MMCs) and ceramic matrix composites (CMCs) according to their matrix materials. A set of mechanical experiments ranging from micro scale (single fiber composite and thin film composite) to macro scale (PMCs and MMCs) were conducted to fully understand the …

Investigation Into The Feasibility Of Adding Turbulators To Rocket Combustion Chamber Cooling Channels Using A Conjugate Heat Transfer Analysis, Tyler Buchanan

Electronic Theses and Dissertations

A conjugate heat transfer analysis will be carried out to simulate an 89 kN thrust chamber hydrogen cooling channel, to determine the feasibility of adding turbulators to the combustion chamber cooling channels at various parameters such as angle, pitch, and height of the turbulator. An existing regeneratively cooled chamber environment is simulated and used as a baseline case to be compared against. The new design includes using ribbed turbulators or delta wedges in the cooling channels to increase the heat transfer on the channel hot wall (wall adjacent to the hot gas wall) and on the two channel sidewalls. With …

Nondestructive Testing Methods Aided Via Numerical Computation Models For Various Critical Aerospace Power Generation Systems, Peter Warren

Electronic Theses and Dissertations

A current critical necessity for all industries which utilize various equipment that operates in high temperature and extreme environments, is the ability to collect and analyze data via non destructive testing (NDT) methods. Operational conditions and material health must be constantly monitored if components are to be implemented precisely to increase the overall performance and efficiency of the process. Currently in both aerospace and power generation systems there are many methods that are being employed to gather several necessary properties and parameters of a given system. This work will focus primarly on two of these NDT methods, with the ultimate …

The Study Of An Impinging Unsteady Jet - Fluid Mechanics And Heat Transfer Analysis, Andrea Osorio

Electronic Theses and Dissertations

The high heat transfer capabilities of impinging jets have led to their widespread use in industrial applications, such as gas turbine cooling. These impinging jets are usually manufactured on the walls of super-alloy metals and are influenced by being positioned with a confined setting. Studies have been shown to enhance the heat transfer of impinging jets by fluctuating the flow which will be analyzed in this project with two designs. The first design is a self-sustaining stationary fluidic oscillator that causes a sweeping motion jet to impinge on the surface. This is investigated using Particle Image Velocimetry (PIV) to study …

Navigation Of An Autonomous Differential Drive Robot For Field Scouting In Semi-Structured Environments, Douglas Freese

Electronic Theses and Dissertations

In recent years, the interests of introducing autonomous robots by growers into agriculture fields are rejuvenated due to the ever-increasing labor cost and the recent declining numbers of seasonal workers. The utilization of customized, autonomous agricultural robots has a profound impact on future orchard operations by providing low cost, meticulous inspection. Different sensors have been proven proficient in agrarian navigation including the likes of GPS, inertial, magnetic, rotary encoding, time of flight as well as vision. To compensate for anticipated disturbances, variances and constraints contingent to the outdoor semi-structured environment, a differential style drive vehicle will be implemented as an …

Application Of Trained Pod-Rbf To Interpolation In Heat Transfer And Fluid Mechanics, Rebecca A. Ashley

Honors Undergraduate Theses

To accurately model or predict future operating conditions of a system in engineering or applied mechanics, it is necessary to understand its fundamental principles. These may be the material parameters, defining dimensional characteristics, or the boundary conditions. However, there are instances when there is little to no prior knowledge of the system properties or conditions, and consequently, the problem cannot be modeled accurately. It is therefore critical to define a method that can identify the desired characteristics of the current system without accumulating extensive computation time. This thesis formulates an inverse approach using proper orthogonal decomposition (POD) with an accompanying …

Equibiaxial Flexural Strength Testing Of Advance Ceramics, Ryan T. Jordan

Honors Undergraduate Theses

Ceramics are very important materials with many unique properties used in numerous industrial applications. Ceramics could be very hard and very strong in comparison to metals; however, they are very brittle, thus they are prone to instantaneous and catastrophic failure. Therefore, their reliability is compromised and it is very important to have advanced techniques that allow evaluating their mechanical behavior in many unusual stress states. One of such testing methods is biaxial strength method, that allows to measure properties not only unidirectional, but also in a biaxial way. The research work for this thesis will be built on design and …

Stochastic Bi-Level Optimization Models For Efficient Operating Room Planning, Amin Abedini, Wei Li, Honghan Ye

Mechanical Engineering Faculty Publications

Within a hospital, the operating room (OR) department has the largest cost and revenue. Because of the aging population, the demand for surgical services has been increasing sharply in recent years. At the other hand, the rate of OR capacity expansion is lower than the rate of increasing demand. As a result, OR managers must leverage their resources by efficient OR planning. OR planning is challenging because of multiple competing\conflicting objectives such cost minimization and throughput maximization. Inherent uncertainty in the surgical procedures and patients arrivals complicate the decision making process. This increases the risk of non-realization of the system …

Turbulent Flame-Vortex Dynamics Of Bluff-Body Premixed Flames, Marissa Geikie

Electronic Theses and Dissertations

This study explores the effects of turbulence and pressure-gradient tailoring on the turbulent flame and vorticity transport mechanisms of premixed flames. A turbulent premixed flame stabilized by a bluff-body in a high-speed combustor is used for the investigation. The combustor pressure gradient is altered using a variable-geometry test section. The turbulence within the combustor is controlled using a custom-designed, supersonic variable-turbulence generator. The turbulent flame-flow field is measured and characterized using simultaneous high-speed particle imaging velocimetry (PIV) and CH* chemiluminescence. The flame-vortex dynamics of the turbulent flame are analyzed using a Lagrangian tracking methodology. Lagrangian fluid elements (LFEs) are tagged …

Damage Characterization Of Aircraft Fuselage Using Vibrothermography Technique-Review And Analysis, Abbasali Saboktakin

International Journal of Aviation, Aeronautics, and Aerospace

Vibrothermogrphy is a promising non-destructive technique that uses ultrasonic elastic waves to detect damages and is typically applied in the aerospace and automotive industries. This technique allows for defect selective imaging using thermal waves that are generated by ultrasound waves. In this paper, vibrothermography technique was applied to the aircraft fuselage to detect its damage. The influence of the damage on the temperature distribution at the damage region on the aluminum was investigated by finite element technique. Comprehensive understanding in edge crack in fuselage heating caused by local friction between crack surfaces was obtained.

Dust Control Examination Using Computational Fluid Dynamics Modeling And Laboratory Testing Of Vortecone And Impingement Screen Filters, Ashish R. Kumar

Theses and Dissertations--Mining Engineering

Heavy industries, such as mining, generate dust in quantities that present an occupational health hazard. Prolonged exposure to the respirable dust has been found to result in many irreversible occupational ailments in thousands of miners. In underground mining applications, a variety of scrubbing systems are used to remove dust near the zones of generation. However, the wire-mesh type fibrous screens in the flooded-bed dust scrubbers used on continuous miners, are prone to clogging due to the accumulation of dust particles. This clogging results in a reduced capture efficiency and a higher exposure to the personnel. This research establishes the Vortecone, …

An Analysis Of Common Drill Stem Vibration Models, Mohammed F. Al Dushaishi, Runar Nygaard, Daniel S. Stutts

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Excessive drill stem (DS) vibration while rotary drilling of oil and gas wells causes damages to drill bits and bottom hole assemblies (BHAs). In an attempt to mitigate DS vibrations, theoretical modeling of DS dynamics is used to predict severe vibration conditions. To construct the model, decisions have to be made on which beam theory to be used, how to implement forces acting on the DS, and the geometry of the DS. The objective of this paper is to emphasize the effect of these assumptions on DS vibration behavior under different, yet realistic, drilling conditions. The nonlinear equations of motion …

Pico Grid-Smart Home Energy Management System, Kristina Istre, James E. Conaway Mr.

ENgaging Educators in Renewable enerGY (ENERGY): Lesson Plans & Slideshows (2017-2019)

No abstract provided.