Other Mechanical Engineering Commons^™

Influence Of Swirl And Turbulence In The Particle Removal Using Fog In A Pipe Flow, Nisarg T. Patel

All Theses

Fog-and-tube scrubbers are employed to remove harmful ultrafine aerosols, such as Diesel particulate matter (DPM), from an airflow. The underlying principle of this removal process involves enlarging the aerosol particles by coagulating them with fog drops, which are subsequently eliminated through inertial impaction onto the tube wall. Previous research conducted by Tabor et al. (2021) demonstrated an increase in scavenging of ultrafine DPM particles, ranging from 11.5 nm to 154 nm, by as large as 45% over the no fog case. This finding is crucial in addressing the challenges associated with conventional filtration methods for capturing ultrafine particles.

The present …

Investigation Of Fatigue Response With Analytical And Machine Learning Models And Hygroscopic Analysis Of Asymmetric Bistable Cfrp Composites, Shoab Ahmed Chowdhury

All Dissertations

Asymmetric bistable carbon fibre reinforced plastic (CFRP) composites enable a broad range of applications as they can sustain multiple stable configurations and have small snap-through load requirements. These unique features, coupled with their light strength-to-weight and stiffness-to-weight ratios, have made them preferred options for multifunctional systems. This study investigates the fatigue and hygroscopic response of 2-ply, [0/90] bistable CFRP laminates and proposes predictive modeling approaches for improved performance.

While previous studies widely researched and documented the fatigue of general composites in axial loading, fatigue analysis of asymmetric bistable composites in the out-of-plane snap-through direction is inadequate. This study performs fatigue …

Extensional Flows Of Polymer Solutions In Planar Microchannels, Mahmud Kamal Raihan

All Dissertations

Non-Newtonian fluids such as polymer solutions often flow under microscale extensional conditions in many natural and engineering flow fields such as in microfluidic chips, porous rocks, biological membranes and filters, printheads in additive manufacturing, etc. The changing cross sectional areas of the internal flow passages therein exert additional extension on the flow along with the shearing. Numerous studies have been dedicated to understanding the extensional flows of polymer solutions over the years. However, most of these studies only focused on flexible polymers exhibiting elasticity in their macroscopic rheology, whereas rigid polymers that portray shear-thinning but often elude elasticity in the …

Water Hammer Analysis For Ash Slurry Disposal Pipelines Of A Thermal Power System, Biprodip Mukherjee, Subhasish Das, Satyapriya Mandal

Journal of Environmental Science and Sustainable Development

Coal-ash slurry transportation via pipelines has been accepted as a potential, economical, and dependable mode of two-phase flow of solid-liquid transportation. It is solid-liquid transportation where the ash slurry generally flows through mild steel, and a good amount of pump energy and pressure is required to convey the slurry with a density above 1220 kg/m3. The study is basically on the water hammer analysis of ash slurry conveying pipes. Nevertheless, since the hammer analysis is typically carried out in normal water, the study of ash slurry is compared to the know criteria of potable water. The study aims to understand …

Twin-Solute, Twin-Dislocation And Twin-Twin Interactions In Magnesium, Materials Yue, Jian Wang, Jian-Feng Nie

Department of Mechanical and Materials Engineering: Faculty Publications

Magnesium alloys have received considerable research interest due to their lightweight, high specific strength and excellent castability. However, their plastic deformation is more complicated compared to cubic materials, primarily because their low-symmetry hexagonal closepacked (hcp) crystal structure. Deformation twinning is a crucial plastic deformation mechanism in magnesium, and twins can affect the evolution of microstructure by interacting with other lattice defects, thereby affecting the mechanical properties. This paper provides a review of the interactions between deformation twins and lattice defects, such as solute atoms, dislocations and twins, in magnesium and its alloys. This review starts with interactions between twin boundaries …

Atomistic Simulations Of Twin Facets Associated With Three-Dimensional { []011 } Twins In Magnesium, Qiyu Zeng, Mingyu Gong, Houyu Ma, Yao Shen, Jian-Feng Nie, Jian Wang, Yue Liu

Department of Mechanical and Materials Engineering: Faculty Publications

Twinning is a deformation mechanism that creates three-dimensional (3D) twin domains through the migration of twin facets. This occurs via the nucleation and glide of twinning disconnections (TDs), which can pile up to create twin facets. A comprehensive under- standing of twin facets associated with 3D twins, including their atomic structures and energies, is crucial for understanding deformation twinning. In this study, we propose a molecular statics/dynamics (MS/MD) approach to determine characteristic twin facets enclosing 3D non-equilibrium/equilibrium { [] 011 } twin domains, which has been much less studied than the counterpart { [] 012 } twin domains. The stability …

The Essential Work Of Fracture In Peridynamics, Christer Stenström, Kjell Eriksson, Florin Bobaru, Stefan Golling, Pär Jonsén

Department of Mechanical and Materials Engineering: Faculty Publications

In this work, the essential work of fracture (EWF) method is introduced for a peridynamic (PD) material model to characterize fracture toughness of ductile materials. First, an analytical derivation for the path-independence of the PD J -integral is provided. Thereafter, the classical J -integral and PD J-integral are computed on a number of analytical crack problems, for subsequent investigation on how it performs under large scale yielding of thin sheets. To represent a highly nonlinear elastic behavior, a new adaptive bond stiffness calibration and a modified bonddamage model with gradual softening are proposed. The model is employed for two …

Mesoporous Particle Embedded Nanofibrous Scaffolds Sustain Biological Factors For Tendon Tissue Engineering, Chiara Rinoldi, Ewa KijeńSka-GawrońSka, Marcin Heljak, Jakub Jaroszewicz, Artur KamińSki, Ali Khademhosseini, Ali Tamayol, Wojciech Swieszkowski

Department of Mechanical and Materials Engineering: Faculty Publications

In recent years, fiber-based systems have been explored in the frame of tissue engineering due to their robustness in recapitulating the architecture and mechanical properties of native tissues. Such scaffolds offer anisotropic architecture capable of reproducing the native collagen fibers’ orientation and distribution. Moreover, fibrous constructs might provide a biomimetic environment for cell encapsulation and proliferation as well as influence their orientation and distribution. In this work, we combine two fiber fabrication techniques, such as electrospinning and wet-spinning, in order to obtain novel cell-laden 3D fibrous layered scaffolds which can simultaneously provide: (i) mechanical support; (ii) suitable microenvironment for 3D …

Enhancement Of Interlaminar Shear Strength Of Carbon Fiber Reinforced Polymer Composites With Freeform 3d Printing Using Magnetic Compaction & Zt-Cfrp Technologies, Mohammad Rakibul Islam

Graduate Theses and Dissertations (2019 - present)

Carbon Fiber Reinforced Polymer (CFRP) laminates often exhibit matrix-sensitive weaknesses and flaws when produced via conventional additive manufacturing (AM) techniques due to the introduction of voids and defects during the AM process. This thesis employs a new approach called Magnetic Compaction Force Assisted-Additive Manufacturing (MCFA-AM) to fabricate Carbon Nanofibers (CNF)Z-threaded CFRP (i.e., ZR-CFRP) composite laminates. This novel method utilized a magnetic force to simultaneously levitate, deposit, and compact Continuous Carbon Fiber Reinforced Polymer (C-CFRP) composites in free space and rapidly solidifies the CFRP part without any mold; and effectively reduces the voids. Previous studies have demonstrated that the incorporation of …

Effect Of Surface Fluid Entrapment In A Laminar Flat Plate Boundary Layer, Abigail Hays

Mechanical Engineering Research Theses and Dissertations

For streamlined objects in laminar flow, the drag is dominated by friction drag. To counteract this, the boundary condition of the object can be changed to introduce an apparent slip on the surface. A number of approaches have been proposed for introducing surface slip to reduce drag and viscous resistance in fluid flows. This work investigates a novel approach to providing slip via fluid entrapment in a perforated domain embedded in the surface. The fluid entrapment system uses a cavity underneath the domain to allow entrapment of fluid of the same type, or supply air to the surface perforations in …

Nitric Oxide: Physiological Functions, Delivery, And Biomedical Applications, Syed Muntazir Andrabi, Navatha Shree Sharma, Anik Karan, S. M. Shatil Shahriar, Brent Cordon, Bing Ma, Jingwei Xie

Department of Mechanical and Materials Engineering: Faculty Publications

Nitric oxide (NO) is a gaseous molecule that has a central role in signaling pathways involved in numerous physiological processes (e.g., vasodilation, neurotransmission, inflammation, apoptosis, and tumor growth). Due to its gaseous form, NO has a short half-life, and its physiology role is concentration dependent, often restricting its function to a target site. Providing NO from an external source is beneficial in promoting cellular functions and treatment of different pathological conditions. Hence, the multifaceted role of NO in physiology and pathology has garnered massive interest in developing strategies to deliver exogenous NO for the treatment of various regenerative and biomedical …

The Potential Of The Implementation Of Offline Robotic Programming Into Automation-Related Pedagogy, Max Rios Carballo, Xavier Brown

Publications and Research

In this study, the offline programming tool RoboDK is used to program industrial robots for the automation sector. The study explores the feasibility of using this non-disruptive robot programming software for classroom use; assesses how well RoboDK can be used to program various robots used in the industry; creates and tests various applications; and pinpoints technical obstacles that prevent a smooth link between offline programming and actual robots. Initial results indicate that RoboDK is an effective tool for deploying its offline programming code to a Universal Robot, UR3e. There are many potential for advanced applications. The goal of the project …

Design And Development Of Ultrabroadband, High-Gain, And High-Isolation Thz Mimo Antenna With A Complementary Split-Ring Resonator Metamaterial, Ammar Armghan, Khaled Aliqab, Meshari Alsharari, Osamah Alsalman, Juveriya Parmar, Shobhit K. Patel

Department of Mechanical and Materials Engineering: Faculty Publications

The need for high-speed communication has created a way to design THz antennas that operate at high frequencies, speeds, and data rates. In this manuscript, a THz MIMO antenna is designed using a metamaterial. The two-port antenna design proposed uses a complementary splitring resonator patch. The design results are also compared with a simple patch antenna to show the improvement. The design shows a better isolation of 50 dB. A broadband width of 8.3 THz is achieved using this complementary split-ring resonator design. The percentage bandwidth is 90%, showing an ultrabroadband response. The highest gain of 10.34 dB is achieved …

Restoration Of Normal Blood Flow In Atherosclerotic Arteries Promotes Plaque Stabilization, Morgan A. Schake, Ian Mccue, Evan T. Curtis, Thomas J. Ripperda Jr., Samuel Harvey, Bryan T. Hackfort, Anna Fitzwater, Yiannis S. Chatzizisis, Forrest Kievit, Ryan M. Pedrigi

Department of Mechanical and Materials Engineering: Faculty Publications

Blood flow is a key regulator of atherosclerosis. Disturbed blood flow promotes atherosclerotic plaque development, whereas normal blood flow protects against plaque development. We hypothesized that normal blood flow is also therapeutic, if it were able to be restored within atherosclerotic arteries. Apolipoprotein E-deficient (ApoE^-/-) mice were initially instrumented with a blood flow-modifying cuff to induce plaque development and then five weeks later the cuffwas removed to allowrestoration of normal blood flow. Plaques in decuffed mice exhibited compositional changes that indicated increased stability compared to plaques in mice with the cuff maintained. The therapeutic benefit of decuffingwas comparable …

Consumer 3d Printing For Remote Control Aircraft Wings: Development Of Novel Wingbox Structure, Ian Clark

University Honors Theses

Remote control aircraft construction and can be a very expensive and time-consuming hobby. With 3D printer consumer adoption rates skyrocketing, there is a gap between demand for RC aircraft and suitable well-designed models available to creators and hobbyists. By creating and testing two iterations of wingbox geometries, this research aims to help close that gap by producing an easily printable wing structure. While there are improvements that can be made on this work, this research has been effective in generating a novel wingbox structure for FFF 3D printing that has distinct advantages over other designs currently available.

Cooled Liquid Rocket Thrust Chamber, Benjamin Gibson, Kealan Frederick Harris, Ryan Frank Schackel, Bjorn Thorsen

Mechanical Engineering

Cooling may affect the thrust output of a small-scale rocket. Little research is published about small-scale rocket performance. We hypothesize the thrust produced varies as the amount of cooling varies. To facilitate assessing this hypothesis, we have designed and built a liquid rocket engine rated for at approximately 25 lb_f of thrust. Our objective was to build in parallel with Cal Poly Space Systems, who built a rocket engine with similar specifications except without cooling. Our challenge is to integrate film cooling, so that the effects of cooling may be compared to Cal Poly Space System’s engine which has …

Perforated Groove Cam Lock, Matthew J. Redmond, Samuel A. Potter, Dylan Weiglein, Andrew Reese

Mechanical Engineering

NASA Artemis III astronauts need a way to attach and detach various tools to an extension handle to be used during lunar EVA sample collection. Because lunar dust is so harsh and abundant, mechanisms must be designed to function regardless of the number of contact particulates. Past designs used on the Apollo missions proved to be problematic for their operators, opening the door for innovative improvement. A new mechanism has been proposed that directly addresses the performance issues of the original handle extension mentioned in NASA’s Apollo mission reports. The new mechanism boasts an open design that promotes dust tolerance …

Flexible Water Cooling, Joshua Terlaje, Andrew Lin, Nicholas Morales, Tanner Parrott

Mechanical Engineering

The goal of this project is to develop and deploy a water-cooling system to reduce the danger of heat exhaustion among communities of farmworkers. Currently, it is difficult to keep chilled water available throughout the workday when using portable water coolers. The idea uses a refrigeration system to chill the water supply by using the power take-off (PTO) on farm equipment and a corresponding generator to get around this restriction.

The project places a strong premium on keeping the chilled water supply at a maximum temperature of 59°F to ensure compliance with the California Department of Industrial Relations' requirements. Each …

Metamaterial-Based Soft Actuators, Savannah June Cheney, Nathan Kessenich, Marco Leen, Merek Mcgill

Mechanical Engineering

For this project the team was tasked with designing a soft actuator that incorporated aspects of mechanical metamaterials. The team’s goal was to demonstrate the feasibility of structural metamaterials in the field of soft robotics and demonstrate a novel response with a final assembly. Also included in the team's discussion are the manufacturing steps, protype tests & results, and suggested future next steps. Following the previous report (critical design review) the team chose to follow the path of designing a continuum robot with metamaterials incorporated into the design. A continuum robot consists of a soft cylindrical body with rigid evenly …

Disc Golf Throwing Robot, Nevada S. Schultz, Sydney M. Lewis, Erick Edmundo Daza, Rachel Alysse Greenberg, Peter M. Kean

Mechanical Engineering

Disc golf companies need better methods to test disc flight. The scope of this project is to create a disc throwing robot that can throw a disc golf driver 450-500 feet, with control over the speed, spin, and release angle. Research shows that multiple disc-throwing products exist; however, none meet the full requirements of this project. The Cal Poly senior project design team created a proof-of-concept machine. This prototype started as a two-wheel mechanism. Eventually, a third wheel was added, allowing for complete control over disc spin. The three-wheel prototype reached 62 mph when perfectly calibrated. The prototype is accurate, …