Engineering Commons^™

The Influence Of Mixing Duct Length And Phase Of Flight On Wall Temperatures Of A Rocket Based Combined Cycle Engine In Ejector And Air-Augmented Modes, Jonathan Grow

Doctoral Dissertations and Master's Theses

Rocket Based Combined Cycle (RBCC) engines have been theorized as a possible means of powering launch vehicles and high-speed atmospheric vehicles. By incorporating aspects of both air-breathing and rocket propulsion, RBCC engines promise up to a 230 % increase in specific impulse over traditional chemical rocket propulsion by entraining a secondary flow of atmospheric air and mixing it with the exhaust of a rocket motor. Students within the Embry-Riddle Future Space Explorers and Developers Society (ERFSEDS) identified a
problem of excessive heating and structural failure of the mixing duct during launch and transonic flight of a student-built flight test vehicle. …

Thermal Transport Across 2d/3d Van Der Waals Interfaces, Cameron Foss

Doctoral Dissertations

Designing improved field-effect-transistors (FETs) that are mass-producible and meet the fabrication standards set by legacy silicon CMOS manufacturing is required for pushing the microelectronics industry into further enhanced technological generations. Historically, the downscaling of feature sizes in FETs has enabled improved performance, reduced power consumption, and increased packing density in microelectronics for several decades. However, many are claiming Moore's law no longer applies as the era of silicon CMOS scaling potentially nears its end with designs approaching fundamental atomic-scale limits -- that is, the few- to sub-nanometer range. Ultrathin two-dimensional (2D) materials present a new paradigm of materials science and …

Analysis Of The Self-Heating Effect On Unfilled Poly(Methyl Methacrylate) Due To Cyclic Behavior, Muhammed R. Kose

All Theses

Poly(methyl methacrylate, (PMMA) has been implemented as part of the supporting structure in complete hip and knee replacements since the 1950s. Known as bone cement while in the body, PMMA is known to undergo compressive and tensile stresses that wear down the bio-compatible barrier and cause pieces to come loose inside the human body. These pieces are then attacked by the body’s own nervous system, leading to inflammation, and eventually necessitating replacement. It has been documented that under cyclic loading PMMA can reach temperatures that start to degrade its tensile capabilities. In this study the potential cause of self-heating was …

State-Of-The-Art Of Thermal Control Solutions To Establish A Modular, Multi-Orbit Capable Spacecraft Thermal Management System Design Methodology, Robert C. Consolo Jr

Doctoral Dissertations and Master's Theses

Today, the exploration and exploitation of space continues to become a more common occurrence. All types of spacecraft (S/C) utilize various types of thermal management solutions to mitigate the effects of thermal loading from the unforgiving vacuum of space. Without an appropriately designed thermal system, components on-board the S/C can experience failure or malfunction due to fluctuations in temperatures either beyond the designed operational parameters or unstable oscillating temperatures. The purpose of this study is to perform a comprehensive review of technologies available today that are being used for thermal management onboard S/C in addition to investigating the means to …

Thermal Vacuum Chamber Modification, Testing, And Analysis, Jared C. Lehmann

Master's Theses

This work discusses the modification and analysis of the Blue Thermal Vacuum Chamber (TVAC) located at the Space Environments Lab at California Polytechnic State University, San Luis Obispo. The modified design has a cylindrical test section and can accommodate 6U Cubesats or larger for educational or research purposes. The sizing process for the modified shroud cooling system and modular heating plates is discussed. The modified cooling system uses existing nitrogen plumbing into the chamber and control systems with a new copper shroud. The modified heating system uses modular heater plates, which utilize the existing three heater strips. The modified system …

A Multi Physics Integrated Solution For A High-Pressure Stage Turbine Efficiency And Durability, Sanjay Chopra

Theses and Dissertations

World electricity demand is projected to grow at an annual rate of ~ 2.1% to year 2040₁. EIA projects nearly 50% increase in world energy usage by 2050 led by growth in Asia.[28];[29]. It is predicted that the global electricity demand grows at approximately 1.6 % per year from approximately 2008 and forecasted to approximately 2035, twice the rate of primary energy demand. This raises electricity's usage in total final energy consumption from approximately 19% in 2018 to approximately 24% in 2040. Electricity demand growth is set to be particularly strong in developing economies. .[28];[29];[38] As an enabler, to meet …

Thermal Testing And Characterization Of Nanoparticles Synthesized For Biological Treatment, Tonie Butler

Mechanical Engineering Undergraduate Honors Theses

The overall goal of this research project is to synthesize iron core, silica capped nanoparticles that, when they are exposed to a particular magnetic field, will react by increasing in temperature and emitting substantial thermal output. They will be injected into the human body for biological benefit by targeted thermal radiation. Once in the human body, ideally, they will be able to target a specific area, and then a magnetic field will be applied to induce thermal output through the process of hyperthermia. As the nanoparticles emit heat, they will mimic the natural bodily behavior seen by way of hyperthermia, …

Thermal/Structural Analysis Of The Axion Quantum Metrology Cavity And Its Components, Tyler Funk

Graduate Research Theses & Dissertations

This research was centered around maximizing the capability to cool dielectric material within a containment unit, or Photonic Band Gap (PBG) cavity, designed for detecting axion dark matter and identifying the unit’s thermal properties. There are multiple types of PBG cavities, but the latest version that axion researchers wish to use has been theorized to contain possible issues related to its thermal properties. Thermal conductivity is an issue with the dielectric material because it is made from alumina which is highly insulative. This is important since the research is being done in a cryogenic environment and the thermal noise affects …

Characterization Of Fiber Bragg Grating Based, Geometry-Dependent, Magnetostrictive Composite Sensors, Edward Lynch

Theses and Dissertations

Optical sensors based on geometry dependent magnetostrictive composite, having potential applications in current sensing and magnetic field sensing are modeled and evaluated experimentally with an emphasis on their thermal immunity from thermal disturbances. Two sensor geometries composed of a fiber Bragg grating (FBG) embedded in a shaped Terfenol-D/epoxy composite material, which were previously prototyped and tested for magnetic field response, were investigated. When sensing magnetic fields or currents, the primary function of the magnetostrictive composite geometry is to modulate the magnetic flux such that a magnetostrictive strain gradient is induced on the embedded FBG. Simulations and thermal experiments reveal the …

Three-Level Converters For Low Voltage Active Front End Motor Drives, Marzieh Karami

Theses and Dissertations

Electric drives with Active Front End (AFE) converters can provide benefits such as lower harmonic current injections to the grid, smaller size filters, lower THD values and cost saving for injection of power to the grid in brake situations. SiC-MOSFET based two-level converters can be a promising topology for Active Front End (AFE) application in electric drives. The possibility of high switching frequency will make the grid filters smaller. Grid filters are used for EMC and power quality issues. However, there are practical limitations for increasing the switching frequency such as dead time in the gating signals, sampling requirements, and …

Efficient Enhancement Of Micro-Nucleation Rates In Flow-Boiling - By Concurrent Micro-Structuring Of The Boiling-Surface And Its Judicious Energization By Piezoelectric-Transducer Induced Acoustic Vibrations., Atharva Rahane

Dissertations, Master's Theses and Master's Reports

The report describes the science and technology backgrounds and uses for the technology breakthrough reported for enhanced flow-boiling based cooling of high-power density electronics (chips, memory etc.). A controlled but explosive growth in micro-scale nucleation rates during flow-boiling of HFE-7100 (electronics and environment friendly liquid from 3M, Inc) is enabled by the uses of inexpensive meshed-copper for micro-structuring of the boiling surface and a pair of Piezoelectric-transducers for active imposition of suitable acoustic vibrations. The pair of piezo transducers mounted just outside the mini-channel impose “in plane” acoustic vibrations of controllable amplitudes and frequencies, and they are used to induce …

Enhanced Heat Transfer In Spray Cooling Through Surface Modifications: An Experimental And Computational Study, Azzam Saadi Salman

Theses and Dissertations

Today, dissipating high heat flux safely is one of the greatest challenges for thermal engineers in thermal management systems, and it becomes a critical barrier to technological developments for many engineering applications. Due to technological advances and aggressive micro-miniaturization of electronic components, the surface area of most devices has shrunk while the computational power increased exponentially. Therefore, the amount of heat dissipated from surfaces has increased significantly. Numerous cooling techniques have been introduced to replace the traditional air cooling systems and to maintain the efficiency and reliability of electronic components. Microelectronics work efficiently and safely at surface temperatures of < 100 ℃ and 125 ℃ for general and defense applications, respectively. One of the proposed alternative schemes is spray cooling, which is considered one of the most advanced cooling methods. It is used for high and ultra-high heat flux dissipation, as it can dissipate 150-200 W/cm2 while maintaining the surface temperature within this range. Also, spray cooling removes a large amount of energy at a lower liquid flow rate compared to other cooling techniques, such as jet impingement and microchannel heat sink. The thermal performance of spray cooling systems can be enhanced either actively or passively. Active enhancement is a very efficient technique; however, it adds more pumping power. The present work focuses on three main objectives: evaluating and analyzing spray cooling performance, developing a three-dimensional numerical multi-phase model for heat transfer process in spray cooling and enhancing the thermal performance of spray cooling passively.

First, …

Sensor System For Rescue Robots, Alexander Moran, Emir Kusculu

Electrical and Computer Engineering Senior Theses

A majority of rescue worker fatalities are a result of on-scene responses. Existing technologies help assist the first responders in scenarios of no light, and there even exist robots that can navigate radioactive areas. However, none are able to be both quickly deployable and enter hard to reach or unsafe areas in an emergency event such as an earthquake or storm that damages a structure. In this project we created a sensor platform system to augment existing robotic solutions so that rescue workers can search for people in danger while avoiding preventable injury or death and saving time and resources. …

Thermal/Mechanical Analysis And Development Of A 2000 Lbf Liquid Oxygen/Liquid Methane Rocket Engine, Marissa Garcia

Open Access Theses & Dissertations

The Center for Space Exploration and Technology Research (cSETR) is developing three rocket engines: a 5 lbf reaction control engine, a 500 lbf engine, and a 2000 lbf engine. All these engines utilize a liquid oxygen and liquid methane propellant combination. The reason methane was selected for the fuel is because methane is easy to store, is self-pressurizing, and readily available. There is also the possibility of creating methane on planets such as Mars through an electrolysis process on the ice water found on Mars.

The 2000 lbf engine, or the CROME-X, is a modular, steady-state pintle injector engine. It …

Expediting The Consolidation Of Clayey Soils Utilizing Microwaves, Thilini Jayatissa

USF Tampa Graduate Theses and Dissertations

Post-construction settlement has been an issue in the field of construction due to the excessive time taken for the dissipation of pore water pressure. This is significant for construction carried out on clayey soils primarily due to the low permeability of clayey soils. Therefore, attention has been directed at finding means of increasing the rate of pre-consolidation. Recent research has focused on the effects of temperature on consolidation. It has been shown that elevated temperature increases the hydraulic conductivity of pore water due to both the reduction of viscosity and differential volumetric expansion of soil and water. This results in …

Thermal Vacuum Chamber Refurbishment And Analysis, Adrian Michael Williams

Master's Theses

Spacecraft are subject to different environments while on orbit around the Earth and beyond. One of the most critical of these environments that must be counteracted is the thermal environment. Each spacecraft has an operating temperature that is specified in the mission requirements. The requirement stems from internal component operating temperatures that are critical to mission success. Prior to placing the spacecraft in orbit, engineers must be sure that the spacecraft will survive or risk losing the mission entirely.

The primary way to mitigate this risk is to use a thermal vacuum chamber (TVAC). The chamber is designed to resemble …

Single-Stage, Venturi-Driven Desalination System, Brandon Proetto

Mechanical & Aerospace Engineering Theses & Dissertations

Water demand is increasing at a rapid pace due to population increase, industrial expansion, and agricultural development. The use of desalination technology to meet the high water demands has increased global online desalination capacity from 47 million m^3/d in 2007 to 92.5 million m^3/d as of June 2017 [49]. Membrane and thermal processes are the two mainstream desalination categories used worldwide for desalination plants. Reverse Osmosis (RO) is the most widely used membrane process and it has become the dominant technology for building desalination plants over recent decades. Thermal distillation, however, has become less and less competitive due to its …

Surfactants, Thermal And Surface Energy Effects On Emulsions’ Transport Properties: A Study Using Lattice Boltzmann Method, Wessam Falih Hasan

Wayne State University Dissertations

This work aims to provide an efficient Gunstensen LBM based CFD model, capable of solving complex problems related to droplets behavior in shear and parabolic flows.

Thermal conditions determine the outcome of the physical and transport properties of emulsions during their various processing phases. A better understanding of the intricate relationship between thermal, surfactants and hydrodynamics can help in the optimization of these processes during the production of emulsions. To investigate the outcome of coupling thermal, surfactants and hydrodynamics on emulsions behavior, a robust quasi-steady thermal-surfactants numerical scheme is presented and used here. To validate the model, the rheological behavior …

Fabrication And Characterizations Of Lagp/Peo Composite Electrolytes For All Solid-State Lithium-Ion Batteries, Jeremy J. Lee

Browse all Theses and Dissertations

With the rise of electric vehicles and increasing dependence on mobile electronics, the demands for lithium-ion batteries have followed in tandem for their high energy and power densities. However, traditional lithium-ion batteries consisting of liquid electrolytes have limited operating temperatures and are susceptible to ignition and subsequent fires. Recently, battery research has diverged into solid state chemistry to address the aforementioned issues. In this research, we systematically investigate a series of ceramic/polymer lithium-ion conducting composite electrolytes, i.e. Li1.4Al0.4Ge1.6(PO4)3 /lithiated polyethylene oxide (LAGP/PEO). Lithiated PEO was prepared with two different lithium salts, LiBF4 and LITFSI. The impacts of the LAGP on …

Longitudinal Thermal And Solute Dynamics In Regulated Rivers, Muhammad Rezaul Haider

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dam releases increase river stage and can reverse groundwater movement into and out of the river. As the flood, thermal, and solute waves travel downstream in a regulated river, the size of the waves is anticipated to be affected both by river processes and exchanges with near river groundwater. This study established a modeling framework to quantify the influences of the groundwater exchanges on the temperatures and solute concentration dynamics along regulated rivers. The wave properties, volume of exchanges, conservative solute mass exchanges, and heat energy exchanges were calculated as a function of time and distance downstream. Results show that …

Thermal Transport In Lithium Ion Batteries: An Experimental Investigation Of Interfaces And Granular Materials, Aalok Jaisheela Uday Gaitonde

Open Access Theses

Increasing usage and recent accidents due to lithium-ion (Li-ion) batteries exploding or catching on fire has inspired research on the characterization and thermal management of these batteries. In cylindrical 18650 cells, heat generated during the battery's charge/discharge cycle is poorly dissipated to the surrounding through its metallic case due to the poor thermal conductivity of the jelly roll, which is spirally wound with many interfaces between electrodes and the polymeric separator. This work presents a technique to measure the thermal conduction across the metallic case-plastic separator interface, which ultimately limits heat transfer out of the jelly roll.

The polymeric separator …

Cogeneration System Comparison For The Akron Water Treatment Plant, Devin J. Pearcy, Madison R. Morgan

Williams Honors College, Honors Research Projects

Cogeneration is a process of electrical power generation that simultaneously harnesses the heat produced from that electrical generation and uses it to supply heat to a space. The Akron Water Plant was identified as potentially benefitting from this technology for two main reasons. First, they have a large and relatively constant electrical load. Second, they have ownership of a significant amount of natural gas wells at the site.

This report analyzes the economic feasibility of installing a cogeneration plant at the Akron Water Plant (AWP). Data was collected for the plant and its operations, including electricity bills, gas bills, plant …

Automated Multi-Modal Search And Rescue Using Boosted Histogram Of Oriented Gradients, Matthew A. Lienemann

Master's Theses

Unmanned Aerial Vehicles (UAVs) provides a platform for many automated tasks and with an ever increasing advances in computing, these tasks can be more complex. The use of UAVs is expanded in this thesis with the goal of Search and Rescue (SAR), where a UAV can assist fast responders to search for a lost person and relay possible search areas back to SAR teams. To identify a person from an aerial perspective, low-level Histogram of Oriented Gradients (HOG) feature descriptors are used over a segmented region, provided from thermal data, to increase classification speed. This thesis also introduces a dataset …

A Study Of Direct Digital Manufactured Rf/Microwave Packaging, John W.I. Stratton

USF Tampa Graduate Theses and Dissertations

Various facets of direct digital manufactured (DDM) microwave packages are studied. The rippled surface inherent in fused deposition modeling (FDM) fabricated geometries is modeled in Ansoft HFSS, and its effect on the performance of microstrip transmission lines is assessed via simulation and measurement. The thermal response of DDM microstrip transmission lines is analyzed over a range of RF input powers, and linearity is confirmed over that range.

Two IC packages are embedded into DDM printed circuit boards, and their performance is analyzed. The first is a low power RF switch, and the second is an RF front end device that …

Reliabilibity Aware Thermal Management Of Real-Time Multi-Core Systems, Shikang Xu

Masters Theses

Continued scaling of CMOS technology has led to increasing working temperature of VLSI circuits. High temperature brings a greater probability of permanent errors (failure) in VLSI circuits, which is a critical threat for real-time systems. As the multi-core architecture is gaining in popularity, this research proposes an adaptive workload assignment approach for multi-core real-time systems to balance thermal stress among cores. While previously developed scheduling algorithms use temperature as the criterion, the proposed algorithm uses reliability of each core in the system to dynamically assign tasks to cores. The simulation results show that the proposed algorithm gains as large as …

Increasing Efficiency Of Thermal Desalination, Jarrod A. Edwards, Mackinzie Washington, Chan Jung, Ben Garrison

Chancellor’s Honors Program Projects

No abstract provided.

Prosthetic Thermal Management Device, Garrett Dowd

Williams Honors College, Honors Research Projects

High temperatures in lower-limb prosthetics can lead to poor user skin conditions and mechanical slippage between the user’s limb and the prosthetic. This report presents an air-cooling device for a lower-limb prosthesis. This device’s purpose is to maintain a constant skin-prosthesis interface temperature. A compact heat sink and small fan were used to transfer the bio-heat to the ambient surroundings. By changing the power of the fan, the thermal resistance of the whole system can be adjusted to match various thermal loads and environmental temperatures. Heat pads were used to mimic the heat generation of a residual limb, and cooling …

Predictive Methods For End Of Life Prognosis In Composites, Vamsee Vadlamudi

Theses and Dissertations

The long-term properties of continuous fiber reinforced composite materials are increasingly important as applications in airplanes, cars, and other safety critical structures are growing rapidly. The mechanical, electrical, and thermal properties of composite materials are altered by the initiation and accumulation of discrete fracture events whose distribution and eventual interaction defines the limits of design, such as strength and life. There is a correlation that exists between the long term behavior of those materials under combined mechanical, thermal, and electrical fields, and the functional properties and characteristics of the composite materials that requires a fundamental understanding of the material state …

A Comparative Study Of Commercially Available Comfort Fabrics, Melinda Elizabeth Finnie

Master's Theses and Doctoral Dissertations

The comfort fabric market continues to grow and become more competitive. Consumers expect their active wear to deliver performance beyond simply being a barrier between their body and the environment. Textile manufacturers have taken notice, and there is a wide range of comfort fabrics on the market. This research tests fabric samples from leading comfort fabric technologies: phase change materials, nanotechnology, modified fiber structure and blends, as well as the original comfort fiber, cotton. The most widely recognized comfort fabric properties concern the thermal and moisture management of a fabric. Using a guarded sweating hot plate, standardized test methods, and …

Application Of A High-Performance Optically Enhanced Solar Thermal Collector System, Timothy H. Cameron

Honors Theses

In an effort to make Union College a more environmentally friendly campus, this research project focuses on the application of Union’s liquid-based solar thermal collector system. The motivation for this research project is due to the increasing demand for renewable energy sources in order to decrease our society’s dependence on fossil fuels. The system features nine, 16-tube, evacuated tube solar modules which absorb radiant solar energy from the sun. Through a two loop system, thermal energy is stored in water within two-80 gallon storage tanks. This research project involves the design, construction, and analysis of two applications in order to …