Mechanical Engineering Commons^™

Cyber-Physical System Characterization And Co-Regulation Of A Quadrotor Uas, Seth E. Doebbeling

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

An Unmanned Aircraft System (UAS) is a Cyber-Physical System (CPS) in which a host of real-time computational tasks contending for shared resources must be cooperatively managed to obtain mission objectives. Traditionally, control of the UAS is designed assuming a fixed, high sampling rate in order to maintain reliable performance and margins of stability. But emerging methods challenge this design by dynamically allocating resources to computational tasks, thereby affecting control and mission performance. To apply these emerging strategies, a characterization and understanding of the effects of timing on control and trajectory following performance is required. Going beyond traditional control evaluation techniques, …

Development Of The End-Effector Of A Cable-Driven Parallel Manipulator For Automated Crop Sensing, Iman Salafian

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

A four cable-driven parallel manipulator (4CDPM), consisting of sophisticated spectrometers and imagers, is under development for use in acquiring phenotypic and environmental data over an acre-sized maize field. This thesis presents the design, controls, and testing of two sub-systems in a 4CDPM: a Center of Mass Balance System (CMBS) and a Drop-Down System (DDS).

One of the factors that influences stability is the center of mass (COM) position of the end effector. An offset in COM can cause a pendulum effect or an undesired tilt angle. A center of mass balancing system is presented in this thesis to minimize the …

Analysis Of Angles-Only Hybrid Space-Based/Ground-Based Approach For Geosynchronous Orbit Catalog Maintenance, Blythe A. Andrews

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geosynchronous Equatorial Orbit (GEO) is critical to Earth communications, weather monitoring, and national defense. Orbit estimation of GEO objects is difficult due to physical constraints placed on ground-based tracking devices such as weather, object range, and tracking frequency restrictions. These constraints are commonly mitigated through the use of two-way signaling devices for cooperative GEO satellites. However, determining the position and velocity of uncooperative GEO satellites and/or objects is more challenging. The objective of this dissertation is to quantify the increased orbital accuracy of objects in the GEO catalog when the Air Force Space Command Space Surveillance Network (AFSPC SSN) is …

Meshless Method For Simulation Of Compressible Flow, Ebrahim Nabizadeh Shahrebabak

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the present age, rapid development in computing technology and high speed supercomputers has made numerical analysis and computational simulation more practical than ever before for large and complex cases. Numerical simulations have also become an essential means for analyzing the engineering problems and the cases that experimental analysis is not practical. There are so many sophisticated and accurate numerical schemes, which do these simulations. The finite difference method (FDM) has been used to solve differential equation systems for decades. Additional numerical methods based on finite volume and finite element techniques are widely used in solving problems with complex geometry. …

Effect Of Multiphase Radiation On Coal Combustion In A Pulverized Coal Jet Flame, Bifen Wu, Somesh Roy, Xinyu Zhao, Michael F. Modest

Mechanical Engineering Faculty Research and Publications

The accurate modeling of coal combustion requires detailed radiative heat transfer models for both gaseous combustion products and solid coal particles. A multiphase Monte Carlo ray tracing (MCRT) radiation solver is developed in this work to simulate a laboratory-scale pulverized coal flame. The MCRT solver considers radiative interactions between coal particles and three major combustion products (CO₂, H₂O, and CO). A line-by-line spectral database for the gas phase and a size-dependent nongray correlation for the solid phase are employed to account for the nongray effects. The flame structure is significantly altered by considering nongray radiation and …

Improving The Floris Wind Plant Model For Compatibility With Gradient-Based Optimization, Jared Thomas, Pieter Gebraad, Andrew Ning

Faculty Publications

The FLOw Redirection and Induction in Steady-state (FLORIS) model, a parametric wind turbine wake model that predicts steady state wake characteristics based on wind turbine position and yaw angle, was developed for optimization of control settings and turbine locations. This paper provides details on the recent changes made to the FLORIS model to make the model more suitable for gradient-based optimization. Changes to the FLORIS model were made to remove discontinuities and add curvature to regions of non-physical zero gradient. Exact gradients for the FLORIS model were obtained using algorithmic differentiation. A set of three case studies demonstrate that using …

Three-Dimensional Printing Of "Green" Fuels For Low-Cost Small Spacecraft Propulsion Systems, Stephen A. Whitmore

Mechanical and Aerospace Engineering Faculty Publications

This paper details the advantages of employing modern additive manufacturing methods to fabricate hybrid rocket fuels for intrinsically safe and green small spacecraft propulsion systems. Using additive manufacturing overcomes multiple issues frequently associated with hybrid propulsion, including poor volumetric efficiency, system ignitability, and low fuel regression rates. When certain three-dimensionally printed thermoplastics are subjected to a high-voltage low-wattage charge, electrostatic arcing along the surface pyrolizes a small amount of material that, with the introduction of an oxidizer, “seeds” combustion and produces immediate and reliable ignition. Thermoplastic fuel grains can be printed with port shapes that enhance burn properties and increase …

Optimum Conditions For Eor Using Nanofluids Subjected To Em Waves, Muhammad Kashif, Poppy Puspitasari

Journal of Mechanical Engineering Science and Technology (JMEST)

Today’s major challenge for oil industry is to improve the oil recovery from the reservoir. Various enhanced oil recovery (EOR) methods have been applied in the field and the steam injection is one of the most favourable methods. The deep reservoir will result in failure of this method due to excessive heat dissipation. In this situation, generating and injecting steam may be uneconomical due to the tremendous reduction of the recovery. Some methods using nanotechnology have been introduced and elaborated. However, we propose the electromagnetic (EM) method as an alternative due to its long range transmission of the transverse waves. …

Analysis Of Strength Of Glass Fibre Composite Leaf Spring Using Finite Element Method, Andoko Andoko, Poppy Puspitasari, Avita Ayu Permanasari

Journal of Mechanical Engineering Science and Technology (JMEST)

Leaf spring, as one of the main components of the suspension system, serves the function of absorbing road shocks and any wheel vibrations, preventing them from being transmitted directly to the vehicle body. Moreover, it can increase the tire traction as well as support the weight of the vehicle and various kinds of external forces. Various studies on the use of composite materials for leaf springs have shown that the strength of composite leaf spring is similar to steel leaf spring with the same load carrying capacity. However, the composite leaf spring has the added advantage of being more lightweight. …

Factors Affecting The Surface Roughness In Sinking Edm Process, Ahmad Atif Fikri, Maftuchin Romlie, Aminnudin Aminnudin

Journal of Mechanical Engineering Science and Technology (JMEST)

The purpose of this study is to gain insights into the surface quality (smoothness) of sinking EDM machining products. Among other non-conventional machining processes, Electrical Discharge Machining (EDM) is the most commonly used process. EDM is a machining process that uses electric sparks created between a workpiece and a tool (electrode). As a manufacturing process, EDM is used for workpieces which have intricate contours and precise dimensions, and works by using electric discharges (sparks) applied in a rapid series of repetitive electrical discharges between the two electrodes, separated by a dielectric fluid, and subject to an electric voltage. Since the …

The Strength Of Moulding Sand Consisting Of A Mixture Of Bentonite, Tapioca Flour, And Sago Flour As A New Binder Formula To Improve The Quality Of Al-Si Cast Alloy, Andoko Andoko, Riana Nurmalasari, M. Alfian Mizar, Retno Wulandari, Poppy Puspitasari, Avita Ayu Permanasari

Journal of Mechanical Engineering Science and Technology (JMEST)

The major factors determining the quality of sand casting products are the base sand and the composition of the sand mould and the binding material. In the foundry industry, the most commonly used binder for creating sand moulds is bentonite. However, the price of bentonite is likely to keep rising. This study aimed at discovering a new binder formula associated with the effect of binder composition i.e. bentonite, tapioca flour, and sago flour on the basis of its mechanical and physical properties. The new formula was expected to be a better binder in the production of sand moulds, resulting in …

Analysis Of Biodegradation Of Bioplastics Made Of Cassava Starch, Nanang Eko Wahyuningtiyas, Heru Suryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Environmental pollution due to plastic waste taking too long to decompose has become a global problem. There have been numerous solutions proposed, one of which is the use of bioplastics. The use of cassava starch as the main ingredient in the manufacture of bioplastics shows great potential, since Indonesia has a diverse range of starch-producing plants. The aim of the present study is to analyse the effect of glycerol on microbial degradation. This experimental research investigated the use of cassava flour mixed with glycerol plasticizer at various concentrations (0, 2, 2.5, 3%) in the synthesis of bioplastics. The aspects studied …

Effect Of Magnetic Field On Diesel Engine Power Fuelled With Jatropha-Diesel Oil, Sukarni Sukarni, Partono Partono, Deni Krisdianto, Retno Wulandari

Journal of Mechanical Engineering Science and Technology (JMEST)

Jatropha oil has characteristics very close to the diesel fuel, so it has good prospects as a substitute or as a mixture of diesel fuel. Previous research showed that jatropha oil usage in diesel engines caused power to decrease. It was probably owing to the higher viscosity of the Jatropha oil compared to that of diesel oil. Installing the magnetic field in the fuel line of a diesel engine fueled with jatropha-diesel oil is expected to reduce the viscosity of jatropha-diesel oil mixture, hence improve the combustion reaction process. This research aims to know the influence of the magnetic field …

Utilization Of Carbon Nanotubes In Electromagnetic Wave Detectors, Muhammad Hanis Zakariah, Poppy Puspitasari

Journal of Mechanical Engineering Science and Technology (JMEST)

Direct detection of hydrocarbon by an active source using electromagnetic (EM) energy termed seabed logging (SBL) has shown very promising results. However, currently available electromagnetic wave technology has a number of challenges include sensitivity and frequency matching. This paper presents development of the carbon nanotubes (CNTs) as electromagnetic wave detector due to outstanding properties of carbon nanotubes. They are currently one of the desired materials for advanced technologies. Two types of detectors were developed in this work, carbon nanotube-based (D1) and without nanotubebased (D2) detectors. Various configuration and arrangement for each type of detector were investigated to determine the one …

Structural Vs.. Compositional Disorder In Thermal Conductivity Reduction Of Sige Alloys, Jihui Nie, Raghavan Ranganathan, Zhi Liang, Pawel Keblinski

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We Use Equilibrium Molecular Dynamics Simulations to Determine the Relative Role of Compositional and Structural Disorder in a Phononic Thermal Conductivity Reduction by Studying Three 50-50 SiGe Alloy Structures: Ordered Alloys, Disordered Alloys, and Amorphous Alloys, as Well as Pure Amorphous Si and Ge Structures for Reference. While Both Types of Disorders Significantly Reduce Thermal Conductivity, Structural Disorder is Much More Effective to This Aim. the Examination of Phonon Lifetimes in Disordered Alloys Shows High Values in a Low Frequency Regime Governed by Umklapp Scattering that Are Reduced Rapidly with Increasing Frequency Following Rayleigh Scattering Behavior. the Local Properties Analysis …

Socio-Economic Implications Of Large-Scale Electric Vehicle Systems, Florida Solar Energy Center, Omer Tatari

FSEC Energy Research Center®

Transportation is a complex, technology-intensive socio-technical system, which needs to be tackled in an integrated manner. Also, transportation as a sector is a significant component of any national economy, and has far-reaching implications both with regard to socio-economic and environmental well-being of the society and within the context of sustainability science. For this reason, sustainable transportation is not only an important field of research within the academia but also an indispensable constituent of a sustainable economy. Therefore, investigating the path to sustainable transportation requires a holistic approach, encompassing the three dimensions of sustainability, i.e. environment, society, and economy. There are …

Evaluation And Enhancement Of Clean Energy Systems: Analytical, Computational And Experimental Study Of Solar And Nuclear Cycles, Nima Fathi

Mechanical Engineering ETDs

Clean (and specifically renewable) energy is steadily improving its global share. However, finite availability of fossil fuels and the growing effects of climate change make it an urgent priority to convince the industry and governments to incentivize investment in the renewable energy field and to make it more attractive by decreasing the capital cost. Until recently, uncertainties in funding limited renewable energy development, especially in the US. That limitation has been one of the barriers to progress. Another limitation of many renewable energy systems is the variability in their output, which makes them unsuitable for baseline power production. Therefore, fossil …

Impact Of Diy Home Manufacturing With 3d Printing On The Toy And Game Market, Emily Peterson, Joshua M. Pearce

Department of Materials Science and Engineering Publications

The 2020 toy and game market is projected to be US$135 billion. To determine if 3D printing could affect these markets if consumers offset purchases by 3D printing free designs, this study investigates the 100 most popular downloaded designs at MyMiniFactory in a month. Savings are quantified for using a Lulzbot Mini 3D printer and three filament types: commercial filament, pellet-extruded filament, and post-consumer waste converted to filament with a recyclebot. Case studies probed the quality of: (1) six common complex toys; (2) Lego blocks; and (3) the customizability of open source board games. All filaments analyzed saved the user …

Radiative Heat Transfer Analysis Of Railroad Bearings For Wayside Hot-Box Detector Optimization, Arthur Mealer, Constantine Tarawneh, Stephen Crown

Mechanical Engineering Faculty Publications

The railroad industry utilizes wayside detection systems to monitor the temperature of freight railcar bearings in service. The wayside hot-box detector (HBD) is a device that sits on the side of the tracks and uses a non-contact infrared sensor to determine the temperature of the train bearings as they roll over the detector. Various factors can affect the temperature measurements of these wayside detection systems. The class of the railroad bearing and its position on the axle relative to the position of the wayside detector can affect the temperature measurement. That is, the location on the bearing cup where the …

The Impact Of Power Curve Estimation On Commercial Wind Power Forecasts - An Empirical Analysis, Gianni Goretti, Aidan Duffy, Tek Tjing Lie

Conference papers

An increasing number of utilities participating in the energy market require short term (i.e. up to 48 hours) power forecasts for renewable generation in order to optimize technical and financial performances. As a result, a large number of forecast providers now operate in the marketplace, each using different methods and offering a wide range of services. This paper assesses five different day-ahead wind power forecasts generated by various service providers currently operating in the market, and compares their performance against the state-of-the-art of short-term wind power forecasting. The work focuses on how power curve estimations can introduce systematic errors that …

A Thermodynamic Study Of Binary Real Gas Mixtures Undergoing Normal Shocks, Josiah M. Bigelow

Mechanical Engineering ETDs

We investigate the difference between Amagat and Dalton mixing laws for gaseous equations of state (EOS) using planar traveling shocks. Numerical modeling was performed in the Sandia National Laboratories hydrocode CTH utilizing tabular EOS in the SESAME format. Numerical results were compared to experimental work from the University of New Mexico Shock Tube Laboratory. Latin hypercube samples were used to assess model sensitivities to Amagat and Dalton EOS. We find that the Amagat mixing law agrees best with the experimental results and that significant difference exist between the predictions of the Amagat and Dalton mixing methods.

Maximizing Operating Room Performance Using Portfolio Selection, Vivek Reddy Gunna, Amin Abedini, Wei Li

Mechanical Engineering Faculty Publications

The operating room (OR) is responsible for most hospital admissions and is one of the most cost and work intensive areas in the hospital. From recent trends, we observe an ironic parallel increase among expenditure and waiting time. Therefore, improving OR scheduling has become obligatory, particularly in terms of patient flow and benefit. Most of the hospitals rely on average patient arrivals and processing times in OR planning. But in practice, variations in arrivals and processing times causes high instability in OR performance. Our model of optimization provides OR schedules maximizing patient flow and benefit at a fixed level of …

An Optimization Model For Operating Room Scheduling To Reduce Blocking Across The Perioperative Process, Amin Abedini, Wei Li, Honghan Ye

Mechanical Engineering Faculty Publications

Operating room (OR) scheduling is important. Because of increasing demand for surgical services, hospitals must provide high quality care more efficiently with limited resources. When constructing the OR schedule, it is necessary to consider the availability of downstream resources, such as intensive care unit (ICU) and post anaesthesia care unit (PACU). The unavailability of downstream resources causes blockings between every two consecutive stages. In this paper we address the master surgical schedule (MSS) problem in order to minimize blockings between two consecutive stages. First, we present a blocking minimization (BM) model for the MSS by using integer programming, based on …

Meniscus-Assisted Solution Printing Of Largegrained Perovskite Films For High-Efficiency Solar Cells, Ming He, Bo Li, Xun Cui, Beibei Jiang, Yanjie He, Yihuang Chen, Daniel O'Neil, Paul Szymanski, Mostafa A. El-Sayed, Jinsong Huang, Zhiqun Lin

Department of Mechanical and Materials Engineering: Faculty Publications

Control over morphology and crystallinity of metal halide perovskite films is of key importance to enable high-performance optoelectronics. However, this remains particularly challenging for solution-printed devices due to the complex crystallization kinetics of semiconductor materials within dynamic flow of inks. Here we report a simple yet effective meniscus-assisted solution printing (MASP) strategy to yield large-grained dense perovskite film with good crystallization and preferred orientation. Intriguingly, the outward convective flow triggered by fast solvent evaporation at the edge of the meniscus ink imparts the transport of perovskite solutes, thus facilitating the growth of micrometre-scale perovskite grains. The growth kinetics of perovskite …

Novel Transducer Calibration And Simulation Verification Of Polydimethylsiloxane (Pdms) Channels On Acoustic Microfluidic Devices, Scott T. Padilla

USF Tampa Graduate Theses and Dissertations

The work and results presented in this dissertation concern two complimentary studies that are rooted in surface acoustic waves and transducer study.

Surface acoustic wave devices are utilized in a variety of fields that span biomedical applications to radio wave transmitters and receivers. Of interest in this dissertation is the study of surface acoustic wave interaction with polydimethylsiloxane. This material, commonly known as PDMS, is widely used in the microfluidic field applications in order to create channels for fluid flow on the surface of a piezoelectric substrate. The size, and type of PDMS that is created and ultimately etched on …

Three Hundred And Sixty Degree Real-Time Monitoring Of 3-D Printing Using Computer Analysis Of Two Camera Views, Siranee Nuchitprasitchai, Michael C. Roggemann, Joshua M. Pearce

Department of Materials Science and Engineering Publications

Prosumer (producing consumer)-based desktop additive manufacturing has been enabled by the recent radical reduction in 3-D printer capital costs created by the open-source release of the self-replicating rapid prototype (RepRap). To continue this success, there have been some efforts to improve reliability, which are either too expensive or lacked automation. A promising method to improve reliability is to use computer vision, although the success rates are still too low for widespread use. To overcome these challenges an open source low-cost reliable real-time optimal monitoring platform for 3-D printing from double cameras is presented here. This error detection system is implemented …

Free And Open Source 3-D Model Customizer For Websites To Democratize Design With Openscad, Yuenyong Nilsiam, Joshua M. Pearce

Department of Materials Science and Engineering Publications

3-D printing has entered the consumer market because of recent radical price declines. Consumers can save substantial money by offsetting purchases with DIY pre-designed 3-D printed products. However, even more value can be obtained with distributed manufacturing using mass customization. Unfortunately, the average consumer is not technically sophisticated enough to easily design their own products. One solution to this is the use of an overlay on OpenSCAD parametric code, although current solutions force users to relinquish all rights to their own designs. There is thus a substantial need in the open source design community for a libre 3-D model customizer, …

Mathematical Description And Mechanistic Reasoning: A Pathway Toward Stem Integration, Paul J. Weinberg

Journal of Pre-College Engineering Education Research (J-PEER)

Because reasoning about mechanism is critical to disciplined inquiry in science, technology, engineering, and mathematics (STEM) domains, this study focuses on ways to support the development of this form of reasoning. This study attends to how mechanistic reasoning is constituted through mathematical description. This study draws upon Smith’s (2007) characterization of mathematical description of scientific phenomena as ‘‘bootstrapping,’’ where negotiating the relationship between target phenomena and represented relations is fundamental to learning. In addition, the development of mathematical representation presents a viable pathway towards STEM integration. In this study, participants responded to an assessment of mechanistic reasoning while cognitive interviews …

Study On The Dispersion Of Particles At A Fluid-Liquid Interface And Its Application In Hydrophilous Pollination, Naga Aditya Musunuri

Dissertations

This dissertation work describes the physics of particle adsorption and the spontaneous dispersion of powders that occurs when they come in contact with a fluid-liquid interface and its application in hydrophilous pollination of Ruppia Maritima, an aquatic plant. The dispersion of particles can occur so quickly that it appears explosive, especially for small particles on the surface of mobile liquids like water. PIV (Particle Image Velocimetry) measurements show that the adsorption of a spherical particle at the interface causes an axisymmetric streaming flow about the vertical line passing through the particle center. The fluid directly below the particle rises upward, …

Fast Estimation Model Of Pressure-Temperature Response For Planning Focused Ultrasound Surgery, Tariq Mohammad Arif

Dissertations

High Intensity Focused Ultrasound (HIFU) is becoming a widely accepted modality for extracorporeal non-invasive hyperthermia and surgical procedures. Since ultrasonic transducers need to operate in various challenging body locations, the arrangement of their array elements can be optimized to improve the capability of controlling focus intensity. In the first part of this dissertation, patterns of pressure field variations with several selected design variables (kerf, transducer element’s number and element’s width-height) are studied. These patterns indicate that there is a more suitable shape and arrangement of transducer elements in a specified area to achieve highest possible pressure. In order to obtain …