Engineering Commons^™

Numerical Simulations Of Comprehensive Hydrodynamic Performance Of Darpa Suboff Submarine, Kenshiro Takahashi

Theses and Dissertations

A numerical study of the DARPA SUBOFF model using computational fluid dynamics (CFD) has been presented for developing a CFD application procedure to compute the hydrodynamic performance of underwater vehicles, including submarines. Several configurations, such as bare hull, fairwater, sterns, and/or ringwing-appended hulls, were examined for the straight-ahead, steady translation and turning, and self-propelled conditions. A systematic study was conducted to ensure an adequate computational domain expansion and reasonable prism layer mesh properties for solutions independent of the parameters. The hydrodynamic forces exerted on the hull and the appendages were verified and validated in accordance with a published methodology under …

Semantic And Qualitative Physics-Based Formal Reasoning For Functional Decomposition In Mechanical Design, Xiaoyang Mao

Theses and Dissertations

Function modeling plays an essential role in academy design studies, yet a lack of acceptance in industry. A possible reason is that the designer must have well understand of the controlled vocabularies and grammars to utilize this method. The research presented in this dissertation is to fill this gap so that designers can use function-based design method without relevant knowledge. In graph-based function models, the function verbs and flow nouns are usually chosen from predefined vocabularies. The vocabulary class definitions, combined with function modeling grammars defined at various levels of formalism, enable function-based reasoning. However, the text written in plain …

Ultrasonic Wave Propagation In Copper/Graphene Metal Matrix Composites, Casey Lindbloom

Mechanical Engineering Undergraduate Honors Theses

Emerging metallic composite materials implanted with graphene sheets are showing immense promise, with benefits being observed with regards to mechanical, thermal, and electrical material properties. This research aims to investigate the effects on ultrasonic wave propagation in Copper/Graphene Metal Matrix Composites (Cu/Gr MMCs) with varying graphene arrangements inspired from nacre and bone nanoscale material distributions. To accomplish this, the molecular dynamics (MD) method is utilized to simulate nanoscale wave propagation on a set of Cu/Gr MMCs with differing graphene arrangements and volume percentages ranging up to 4.56%. The computational model results are then analyzed to determine the variation in energy …

Hvac System Energy Audit For Leverett Elementary School, Connor Smalling

Biological and Agricultural Engineering Undergraduate Honors Theses

Leverett Elementary School is located in Fayetteville, AR. The school needs significant upgrades to its infrastructure. The Fayetteville Public School District has voted to pursue an Energy Services Performance Contract (ESPC) in order to finance the desired upgrades to Leverett Elementary, among other schools in the district.

The scope of this thesis was to perform an energy audit on the existing heating, ventilation, and air conditioning (HVAC) system. By using an energy modeling software, eQuest, the building and the existing base system were modeled to determine utility consumption. Three different HVAC system alternatives were analyzed against the base system by …

Vehicle Interior Access Deployable Worksurface Mechanism Concept Product Design, Premchand Gunachandran

Theses and Dissertations

by

Premchand Gunachandran

The University of Wisconsin-Milwaukee, 2019

Under the Supervision of Professor Mohammad Habibur Rahman

Easy access and adjusting the vehicle interior configuration to a variety of situations and uses is the general desire for any vehicle user. To meet such desire an attempt has been made in this study to conceptualize a design to develop a new mechatronic product called re-configurable vehicle interior console mechanism to deploy a worksurface (DWS), which will provide flexible use of the vehicle’s interior of both partial and fully autonomous vehicles. This re-configurable vehicle interior console will deploy the DWS using a power …

Damage Resistance And Tolerance Of 3d Woven Composites, Justin T. Mcdermott

Electronic Theses and Dissertations

Composite materials have been adopted into primary aircraft structures by virtue of their great strength-to-weight and stiffness-to-weight ratios, fatigue insensitivity, and corrosion resistance. These characteristics are leveraged by aircraft designers to deliver improved fuel effciency and reduced scheduled maintenance burdens for their customers. These benefits have been impressively realized in the Boeing 787 and Airbus A350 XWB, with airframes utilizing about 50% composites by weight. Tempering these successes, however, are the inherent vulnerabilities of carbon-fiber reinforced composites. When compared to conventional metallic structure, composite laminates are more sensitive to stress concentrations at mechanical fastenings and damage due to low-velocity impact. …

Gearbox Baffle Optimization, Megan Arduin

Masters Theses

Current literature reveals there is limited consensus on the placement of baffles within a gearbox to reduce churning losses. Thus, there is a need for a process to identify baffle clearances that result in maximum and minimum churning losses. There are two types of baffles: axial and radial. While both axial and radial baffles cause reductions in churning losses to various degrees, the focus is on the effect of radial baffles. The effect of a board (rectangular plate) baffle location on the churning losses of a single gear gearbox are evaluated using computational fluid dynamics (CFD) implemented in Ansys. Several …

Backstepping Approach For Design Of Cascaded Pid Controller With Guaranteed Trajectory Tracking Performance For Micro-Air Uav, Yusuf Kartal

Mechanical and Aerospace Engineering Theses

Flight controllers for micro-air UAVs are generally designed using Proportional- Integral-Derivative (PID) methods, where the tuning of gains is difficult and time-consuming, and performance is not guaranteed. In this thesis, we develop a rigorous method based on the sliding mode analysis and nonlinear backstepping to design a PID controller with guaranteed performance. This technique provides the structure and gains for the PID controller, such that a robust and fast response of the UAV for trajectory tracking is achieved. First, the second-order sliding variable errors are used in a rigorous nonlinear backstepping design to obtain guaranteed performance for the nonlinear UAV …

Material Characterization And Fracture Prediction Of Fdm Printed Parts, Sanchita Sheth

Mechanical and Aerospace Engineering Theses

In order to take advantage of the design freedom that Additive Manufacturing offers, most applications require reliable material characterization. This can ensure that a design performs within its environment and life requirements. This work discusses two models. One investigates the raster angle dependency of stiffness properties and the other numerically predicts fracture in Fused Deposition Modeling (FDM) printed polymer parts. Pre-processing of FDM geometry was done in Abaqus CAE (SIMULIA TM). FEA and post-processing was done in BSAM, which is a damage prediction software developed for composites. BSAM uses a regularized extended finite element approach of Discrete Damage Modeling. In …

Development And Testing Of A Control Strategy For Dynamic Cooling At Rack Level In Data Centers, Amrutha Valli Rachakonda

Mechanical and Aerospace Engineering Theses

Cooling is a critical part of data center’s infrastructure, and with ongoing demands in data processing and storage, thermal management issues are of great concern. Some imperative methods of removing heat are either using air or liquid (preferably water or refrigerant). When high power density modules are involved, liquid cooling addresses some of the problems faced by air cooling as liquid coolants have higher thermal capacitance. Also, in the case of multi-chip modules, a non-uniform heating due to multi-core generates hot-spots and increases temperature gradients across the module. A dynamic cold plate along with a self-regulated flow control device was …

Static Response Calibration Of 3d Printed Thin Walled Structures Using Fused Deposition Modelling, Akhilesh Ravindra Kulkarni

Mechanical and Aerospace Engineering Theses

3-D printing has enabled flexible, tool-less fabrication that yields numerous benefits. One benefit is unique and complex structural arrangements that increase design freedom to minimize weight. Such arrangements can be guided by advanced topology, shape, and sizing optimization tools using appropriate process constraints to ensure a printable design and can include highly integrated structural details such as stiffeners, flanges, frames, and other connections. 3D printing thin wall aircraft structures presents challenges for material and structural characterization. 3D printing enables integrated structural details, each detail is affected by the print process capability to fabricate the local geometry and deviations from designed …

A Robust Controller Design For A Tailless Uav With Effective Control Allocation, Ethem Hakan Orhan

Mechanical and Aerospace Engineering Theses

Attempts to completely remove the tails from aircraft can be dated back to the early days of modern aviation. A number of stability and control problems arising from the unique characteristics of the configuration resulted in poor handling qualities and some dangerous flight characteristics in the early designs. Lately, this configuration is becoming widespread again and the current state-of-the-art of fly-by wire technology and modern control design techniques enable design of tailless aircraft which are safe to fly. In this thesis, a study on the application of modern robust control design techniques on a tailless UAV is presented. A nonlinear …

Autonomous Carrier Landing Of A Fixed-Wing Uav With Airborne Deck Motion Estimation, Metin Kus

Mechanical and Aerospace Engineering Theses

This study focuses on the design, implementation, and evaluation of an autonomous carrier landing system featuring an airborne deck motion estimation module. The three-dimensional dynamics of a fixed-wing UAV with the actuator and engine dynamics are considered. A carrier motion model that accounts for the perturbations caused by various sea states is built. An airborne measurement system, which is composed of a calibrated camera and light-emitting beacons, is utilized to detect several coplanar target points on the moving carrier deck. The known correspondence between the locations of the target points and their coordinates on the focal plane of the camera …

Characterization Of Thermo-Mechanical Properties Of Copper Nano-Particles Infused Acrylonitrile Butadiene Styrene (Abs)- 3d Printed Specimens, Viswajit Talluru

Mechanical and Aerospace Engineering Theses

Now a days the use of metal nanoparticle infused polymer is becoming widespread, since the development of polymer with enhanced thermal properties are being used for the growth of electronic packaging industry. In this study, copper nanoparticles are mixed with the Acrylonitrile Butadiene Styrene (ABS) thermoplastic in varying mass proportions, to observe the changes in thermal and structural properties of ABS. As expected, the extruded wire with high nano-particle concentration exhibited much higher thermal conductivity than its raw ABS form. For the case of 2% copper nanoparticle infused ABS using one dimensional steady state heat flux method though extrude wire …

Isolated Nucleus Stiffens In Response To Low Intensity Vibration, Joshua Newberg

Boise State University Theses and Dissertations

The nucleus, central to all cellular activity, relies on both direct mechanical input and its molecular transducers to sense and respond to external mechanical stimuli. This response occurs by regulating intra-nuclear organization that ultimately determines gene expression to control cell function and fate. It has long been known that signals propagate from an extracellular environment to the cytoskeleton and into nucleus (outside-in signaling) to regulate cell behavior. Emerging evidence, however, shows that both the cytoskeleton and the nucleus have inherent abilities to sense and adapt to mechanical force, independent of each other. While it has been shown that isolated nuclei …

Thermoresponsive Switchable Solvents For Enhanced, Simultaneous Microalgae Oil Extraction Reaction For Biodiesel Production, Mukhtar Ahmed Ismail

Mechanical Engineering Theses

In this study, a thermo-responsive switchable solvent (TSS), with a tunable hydrophobicity by simply changing the temperature (between 25 to 45oC) was used for simultaneous lipids extraction from wet microalgae and biodiesel production. By manipulating the hydrophobicity of the solvent, the cell wall disruption, lipid extraction and transesterification, and product separation steps were all carried out in a single pot, while eliminating the need for the energy intensive and time-consuming drying step. To overcome the problems currently encountered by using conventional alkaline catalysts in the transesterification of lipids, immobilized enzyme has been used. The proposed TSS consisted of an ionic …

Numerical Modeling Of Phase Transition In Shock Tube Problem, Man Minh Le

Theses and Dissertations

In this work, we developed a numerical model for phase transition in shock-tube problem. This work focused on simulating shock-tube problem and the numerical framework is based on a two-phase flow model. Our simulation tool is an in-house FORTRAN multiphase compressible flow solver, RocSDT [31]. Specifically, this involves the Euler equations along with the Stiffened Gas Equation of State (EOS), an interface of liquid-gas type, and the effects of heat and mass transfer due to phase transition. This thesis described the implementation and incorporation of a phase transition model into a system of five partial differential equation model and the …

Hydrodynamic Ram Analysis Of Bonded Composite Fuel Tanks, Teddy Sedalor

Theses and Dissertations

Military aircraft are tested against a variety of ballistics threats as part of their design to assess their vulnerability. One aspect of this approach/requirement is Hydrodynamic Ram testing which accounts for projectile impact into fuel tanks. Hydrodynamic Ram (HRAM), which occurs due to overpressure created in an enclosed fluid as a result of the transfer of energy and momentum from a penetrating projectile, can be quite destructive to the enclosing structure, which makes testing expensive. Therefore the need arises for numerical methods to supplement the testing and provide more test data than can be obtained directly from the article test. …

Integration Of Inboard Propulsion In Shock Mitigating Membrane Hull Technology, Korrey Rotkiske

Theses and Dissertations

Membrane Hull Technology is a strength based marine vessel design concept that seeks to utilize the in-plane properties of fiber reinforced composites to generate a lighter weight vessel with inherent shock mitigation benefits. MHT has been applied on several Naval crafts yet the design features of inboard propulsion systems have not been addressed. Inboard propulsion systems are a very common form of propulsion used in many types of marine vessels especially larger vessels. This thesis seeks to overcome the inboard engine mounting challenges of MHT which limits use of this technology in the marine industry. The fundamental design elements of …

Flight Test Data System For Strain Measurement, Zachary David Wilson

Master's Theses

This thesis describes the design and evaluation of two devices to be included in the next generation of the family of devices called the Boundary Layer Data System (BLDS). The first device, called the Quasi-Static Strain Data Acquisition System, is a continuation of the BLDS-M series of devices to be known as the Flight Test Data System (FTDS) that uses a modular approach to acquire non-flow, quasi-static mechanical strain measurements. Various breakout boards and development boards were used to synthesize the device, which were housed by a custom PCB board. The system is controlled by the Simblee^TM System on …

Hybrid Iii 95th Percentile Large Male Finite Element Model Neck Alteration, Eric Riley Day

Master's Theses

The motivation behind the project was to update the Livermore Software Technology Corporation (LSTC) Hybrid III 95th percentile finite element model, such that the neck assembly response under varying simulated loading conditions equals that of the federally regulated Hybrid III 95th percentile anthropomorphic testing device (ATD).

The family of Hybrid III crash test dummies approximate the physical properties and response of the human body in a frontal automotive crash. The Hybrid III is used to assess the effectiveness of vehicle restraint systems. LSTC offers Hybrid III finite element models for use in their Multiphysics simulation software package, LS-DYNA. The Hybrid …

Application Of Solar Water Heaters For Industrial Use, Lucas T. Atkins

Theses and Dissertations

Solar water heating is a technology that is mainly used for domestic water heating in residential homes. In most applications, the idea is to make a home “off the grid” in that there is no requirement for outside infrastructure or need for energy utility to provide power to this home. This falls in line with the trend of “going green” in an effort to reduce energy use, increase efficiency, or reduce emissions and other harmful byproducts.

This technology can be adapted to reduce the energy costs of industrial manufacturing plants. By eliminating the need for certain sections of a process …

Graphene-Fibers Hybrid Structures As Adsorbents For Heavy Metal Ions In Aqueous Solutions, Dulce C. Capitanachi

Theses and Dissertations

The project focuses on the study of graphene-fiber hybrid structures for adsorption of heavy metal ions in aqueous solutions. Polyvinyl alcohol-based graphene–fiber structures were created using centrifugal spinning and a carbonization process.

Characterization methods of the graphene–fiber hybrid structures (GFHS) include SEM, FTIR, TGA, and EDX. Single-step batch-type adsorption studies were performed to analyze the interaction of Cu (II) and Pb (II) ions onto GFHS surface. Different heavy metal ion concentrations were used, as well as a variation of pH values. Elemental analysis of the adsorbent’s surface after filtration experiments was studied by EDX and spectroscopy to verify the presence …

Design And Testing Of A Modular Laser System With Laser Machining And Bioprinting Capabilities, Jesus Gonzalez

Theses and Dissertations

This thesis introduces the applications of ultrafast lasers while focusing on their bioprinting capabilities. A custom system was designed to utilize a femtosecond laser for 2D and 3D applications. The characteristics of lasers allow them to be efficiently used in machining, 3D printing, research, and more. Their power and precision allow them to be used for delicate work such as bioprinting. Bioprinting is a field holding great potential to benefit society. Studies conducted over the years prove its usefulness in printing cells and biomaterials, while showing there is still much to improve upon before being able to print fully functioning …

Evaluation Of The Most Significant Factors Influencing The Production Rates Of Highway Construction Activities, Angelica M. Neira

Theses and Dissertations

The utilization of realistic production rates is key for the accurate estimation of the contract time in highway projects. Several factors have an impact on production rates and change the total duration of construction projects. To organize and complete projects in a timely, quality and financially responsible manner, projects need to be scheduled carefully. Schedulers and planners of the Texas Department of Transportation (TxDOT) have been noticing that the estimated timelines are far from the reality and want to investigate if external factors can be the cause of this discrepancy. Some of the factors considered in this study are the …

An Advanced Approach For Contract Time Determination In Highway Projects, Cuauhtemoc Torres Cantu

Theses and Dissertations

In project management, finishing a project on schedule is one of the most important aspects. The Texas Department of Transportation (TxDOT) has been experiencing delays in some projects that can be accounted to an inaccurate project time estimation process. This research presents the development of a user-friendly and comprehensive computer-based contract time determination system. The enhanced system implements probabilistic scheduling techniques such as Program Evaluation and Review Technique, and Monte Carlo Simulation. Additionally, the application of a lognormal two-point PERT method is explored in this study. The new system proposes the use of a database of production rates based on …

Deployable Cover For Cubesat Fuv Imager, Edwin J. Rainville, Patrick J. Rainville, Jeff Wagner

Mechanical Engineering

The goal is to develop a deployable cover for a far ultraviolet imager cube satellite that will be used to map the earth’s auroras in the ionosphere. The deployable cover is used to protect the Far Ultra-Violet (FUV) sensor and lenses, house two mirrors which are used to filter unwanted light and expose optics when deployed. The deployable cover consists of a door, an actuator, a lockout mechanism, and an “open position” indicator. This project also includes designing a fixture for testing the optical alignment of the deployable cover after launch and during orbital conditions. The subassembly is required to …

Waste Gasification, Glyn D. Lewis, Nash Taylor, Nicholas L. Ordonez, David S. Mccallum

Mechanical Engineering

This document summarizes the work the IGT Team has conducted on the topic of waste to energy gasification over the Cal Poly Winter, Spring, and Fall quarters of 2019. The project is being carried out by four Cal Poly Mechanical Engineering students: Nash Taylor, Glyn Lewis, David McCallum, and Nicholas Ordonez and the sponsor of this project is Tod duBois. The team’s original goal was to successfully create a system that compiles residential solid waste on a small scale, gasifies it, and measures the typical syngas outputs, so that the team may assess the viability of gasification of household waste …

Fiberglass Mat-Roll Carryover, Bryce Youngson, Aaliyah Ramos, Johann Cayaban, Tony Ledesma

Mechanical Engineering

The asphalt shingle is a type of roof shingle that uses asphalt for waterproofing. Its low cost and easy installation make it one of the most common roof covers in North America. General Aniline and Film (GAF) is one of the nation’s largest manufacturers of roofing materials and produces asphalt shingles at their Shafter, California manufacturing facility. To manufacture asphalt shingles, a base material of fiberglass passes through a series of processes that sequentially add asphalt, ceramic-coated mineral granules, and thermoplastic adhesive. The fiberglass base-material arrives at the manufacturing facility in large rolls that workers must periodically splice together in …

Katie's Jogger, Megan Guillermo, Erin Wint, Abdullah Sulaiman, Kathryn Mangiaracina

Mechanical Engineering

Edward Robinson is an avid runner who would like to take his daughter on runs. His daughter, Katie, is 100% wheelchair bound and currently does not fit in any commercial joggers on the market. The project team was expected to design, build, and test a custom working prototype of a jogger that the sponsor can use to take his daughter on runs. This entire project was performed over a span of three quarters.