Engineering Commons^™

Experimental Investigation Of Mist Film Cooling And Feasibility Study Of Mist Transport In Gas Turbines, Reda M. Ragab

University of New Orleans Theses and Dissertations

In the modern advanced gas turbines, the turbine inlet temperature may exceed 1500°C as a requirement to increase power output and thermal efficiency. Therefore, it is imperative that the blades and vanes are cooled so they can withstand these extreme temperatures. Film cooling is a cooling technique widely used in high-performance gas turbines. However, the film cooling effectiveness has almost reached plateau, resulting in a bottleneck for continuous improvement of gas turbines' efficiency.

In this study, an innovative cooling scheme, mist film cooling is investigated through experiments. A small amount of tiny water droplets with an average diameter about 10-15 …

A Numerical Study Of High Temperature And High Velocity Gaseous Hydrogen Flow In A Cooling Channel Of A Ntr Core, Sajan B. Singh

University of New Orleans Theses and Dissertations

Two mathematical models (a one and a three-dimensional) were adopted to study, numerically, the thermal hydrodynamic behavior of flow inside a single cooling channel of a Nuclear Thermal Rocket (NTR) engine. The first model assumes the flow in the cooling channel to be one-dimensional, unsteady, compressible, turbulent, and subsonic. The working fluid (GH₂) is assumed to be compressible. The governing equations of the 1-D model are discretized using a second order accurate finite difference scheme. Also, a commercial CFD code is used to study the same problem. Numerical experiments, using both codes, simulated the flow and heat transfer …

A Study On The Integration Of A Novel Absorption Chiller Into A Microscale Combined Cooling, Heating, And Power (Micro-Cchp) System, Scott J. Richard

University of New Orleans Theses and Dissertations

This study explores the application of micro-CCHP systems that utilize a 30 kW gas microturbine and an absorption chiller. Engineering Equation Solver (EES) is used to model a novel single-effect and double-effect water-lithium bromide absorption chiller that integrates the heat recovery unit and cooling tower of a conventional CCHP system into the chiller’s design, reducing the cost and footprint of the system. The results of the EES model are used to perform heat and material balances for the micro-CCHP systems employing the novel integrated chillers, and energy budgets for these systems are developed. While the thermal performance of existing CCHP …

Sodhana Environmental - Final Design Report, Eric Taylor, Corissa Bellis, Cody Perez, Cameron Zeller

Mechanical Engineering

A fully designed cost-effective, sustainable, toilet for the developing world.

Heat Transfer Experiment: Energy Conservation, Ben Ward, Brett Wallace, Ryan Waltman

Mechanical Engineering

This proposal, prepared for the Mechanical Engineering Department by the HTEC design team will redesign and replace the current energy conversion lab that is inaccurate and out of date. The team will evaluate methods of energy conversion, specifically using braking systems, as well as existing labs in order to design an accurate and relatable experiment for this lab. The project team will work with Professor Kim Shollenberger in order to design an experiment that demonstrates energy conversion through the first law of thermodynamics while utilizing a common device that is practical in student’s lives. The final result of this project …

A Novel Approach To Multiphysics Modeling Of Heat And Mass Transfer In Porous Media, Seth Allen Pemberton

Masters Theses

This thesis aims to investigate conjugate heat and mass transfer in porous media with an emphasis on textiles. Both hygroscopic materials, those that absorb water vapor, and non-hygroscopic materials are examined. A model was developed that utilizes COMSOL’s equation-based partial differential equation (PDE) interface which allows the user to input any equation(s) to be solved. By the use of experimental and numerical data each part of the model, i.e. flow field, gas diffusion, convection and vapor absorption, is verified. The accuracy of the equation-based unsteady flow field is verified by modeling the flow over a circular cylinder and extracting the …

Modeling And Validation Of Heat Transfer Present In A Solar Thermal Collector, Eric Ezekiel Stannard

Masters Theses

A solar absorber panel for a solar water heating system located at the College of Architecture’s New Norris House in Norris, TN was modeled and validated against field data in this work. The purpose of this modeling was to create the foundations of a tool that can be used in collector design and building energy simulations. This tool would take into account the radiometric properties of the collector materials, which are essential for an accurate model. Solar water heaters convert the shortwave energy of the Sun into usable heat for residential and industrial applications and have the potential to greatly …

Characterization Of Heat Transfer Coefficient Uncertainty In Support Of High Temperature Probe Measurement Technology, Marcus S. Conner

Masters Theses

The development of new materials and processes have enabled defense, industrial, and research devices that operate in high temperature environments. Measurement technology must keep up with the demand of these environments.

The objective of this work is to provide a correlation between the heat transfer coefficient (and Nusselt Number) and the flow Reynolds number (and Prandtl number) for a truncated cylindrical probe. The correlation provides reduced uncertainty for materials whose heat transfer coefficient is not well defined. The configuration for the experiment uses the University of Tennessee Space Institute’s (UTSI) blow down air supply system discharging into a duct and …

Investigation Of The One-Probe And Two-Probe Calibration Integral Equation Methods Using Experimental Data, Abhay Sanjeev Pande

Masters Theses

This work aims to expand the applicability of the recently devised physics-based Calibration Integral Equation Method (CIEM) at the University of Tennessee Knoxville, for solving the Inverse Heat Conduction Problem (IHCP) as applied to a one-dimensional domain. Contrary to conventional schemes of solving the IHCP, the CIEM does not require the knowledge of the thermo-physical properties of the domain, sensor characterization and sensor probe locations. The pertinent information is implicitly accounted for via an experimental run. The experimental run ‘calibrates’ the physics of the domain and is called the ‘calibration run’. The net surface heat flux during a real ‘unknown’ …

Hydrogeological And Thermal Sustainability Of Geothermal Borehole Heat Exchangers, S. Emad Dehkordi

Electronic Thesis and Dissertation Repository

Assessment of the current approach taken by guidelines and design methods of vertical closed loop heat exchangers shows that often groundwater flow is either disregarded or is not methodically incorporated. The state of scientific research in this arena reveals that overlooking the groundwater flow in the design procedure may not always be a correct assumption. The significance of advective heat transport compared to conduction is defined by the groundwater flux or Darcy velocity which heavily depends on the hydraulic conductivity of the ground, followed by the hydraulic gradient which has a relatively limited range. A sensitivity analysis on ground and …

An Investigation Of Phase-Change Effects During Rapid Compression Machine Experiments, Colin Banyon

Master's Theses (2009 -)

Rapid compression machines (RCMs) are well characterized laboratory scale devices capable of achieving internal combustion (IC) engine relevant thermodynamic environments. These machines are often used to collect ignition delay times as targets for gas-phase chemical kinetic fuel autoigntion models. Modern RCMs utilize creviced piston(s) to improve charge homogeneity and allow for an adequate validation of detailed chemistry mechanisms against experiments using computationally efficient, homogeneous reactor models (HRMs). Conventionally, experiments are preformed by introducing a premixed gas of fuel + oxidizer + diluent into the machine, which is compressed volumetrically via a piston. Experiments investigating low-vapor pressure fuels (e.g. diesels, biodiesels, …

Channel Flow Behaviour During Mixed Convection At Low Reynolds Numbers, Ahmed Elatar

Electronic Thesis and Dissertation Repository

The effect of mixed convection on low Reynolds numbers flow inside a horizontal square channel heated from below have been investigated experimentally. The channel flow rate ranged from 0.0210 kg/s to 0.0525 kg/s which correspond to Reynolds numbers between 300 and 750 in the absence of heating. The channel bottom surface temperature was controlled and varied from 30 ºC to 55 ºC (Grashof number ranged between 6.37×10⁶ and 3.86×10⁷). Planer Particle Image Velocimetry (PIV) technique was used to measure two-dimensional velocity fields in the channel mid-vertical plane and two horizontal planes close to the bottom heated wall. …

An Applied Numerical Simulation Of Entrained-Flow Coal Gasification With Improved Sub-Models, Xijia Lu

University of New Orleans Theses and Dissertations

The United States holds the world's largest estimated reserves of coal and is also a net exporter of it. Coal gasification provides a cleaner way to utilize coal than directly burning it. Gasification is an incomplete oxidation process that converts various carbon-based feedstocks into clean synthetic gas (syngas), which can be used to produce electricity and mechanical power with significantly reduced emissions. Syngas can also be used as feedstock for making chemicals and various materials.

A Computational Fluid Dynamics (CFD) scheme has been used to simulate the gasification process for many years. However, many sub-models still need to be developed …

Essentially Analytical Theory Closure For Space Filtered Thermal-Incompressible Navier-Stokes Partial Differential Equation System On Bounded Domains, Mikhail Alexandrovich Sekachev

Doctoral Dissertations

Numerical simulation of turbulent flows is identified as one of the grand challenges in high-performance computing. The straight forward approach of solving the Navier-Stokes (NS) equations is termed Direct Numerical Simulation (DNS). In DNS the majority of computational effort is spent on resolving the smallest scales of turbulence, which makes this approach impractical for most industrial applications even on present-day supercomputers. A more feasible approach termed Large Eddy Simulation (LES) has evolved over the last five decades to facilitate turbulent flow predictions for reasonable Reynolds (Re) numbers and domain sizes. LES theory uses the concept of convolution with a spatial …

Numerical Modeling Of Heat Pipe Radiator And Fin Size Optimization For Low And No Gravity Environments, Virginia Ruth Bieger

UNLV Theses, Dissertations, Professional Papers, and Capstones

A heat-pipe radiator element has been designed and modeled to study the efficiency of heat transfer for low and no gravity environments, like in lunar environments. The advantages of using heat pipe includes the significant weight reducing and heat transfer efficiency. The heat transfer can be enhanced by the use of condenser sections with attached fins.

A series of various geometries of solid fins and heat pipes with and without fins were modeled using FLUENT®. This was done to determine the validity of using a heat pipe in lieu of a solid fin projection. A heat pipe had a 25 …

Flame Temperature Imaging Of A Low Nox Burner Via Laser Rayleigh Scattering, Nicholas A. Smith

Master's Theses (2009 -)

Federal and global legislation are requiring increasingly stringent emission regulation on household appliances and in particular water heater burners. Emissions like NOx (NO and NO2) are a growing concern due to their adverse health effects and contribution to tropospheric ozone, acid rain, and smog formation. As NOx is more closely controlled, appliance manufacturers are developing low emission burners for use in water heaters.

Flame temperature is strongly correlated to NOx production. Hence, characterizing flame temperatures in new burners is a key part of improving upon burners used today and the development of future burners. Temperature measurements applied to a new, …

Investigation Of Thermal Properties And Latent Heat Reduction Mechanisms In Nanofluid Phase Change Materials, Aitor Zabalegui

Mechanical Engineering Master's Theses

The thermal properties of paraffin-based nanofluids have been examined to investigate the use of enhanced phase change materials (PCMs) for thermal energy storage (TES). PCMs are promising for TES applications, but low thermal conductivity limits their rate of heat exchange with a working fluid. The nanofluid approach has been established as a method of thermal conductivity enhancement, but effects of particle addition on other thermal properties affecting TES are relatively ignored. Significant reduction in latent heat of fusion below traditional effective medium theory has been observed in nanofluids. An experimental study of paraffin nanofluids, containing various diameter multi-walled carbon nanotubes, …

High Temperature Filter Test Unit Upgrades, Blair Frandeen, Will Schill, Erick Shewmaker, Joshua Turgeon

Mechanical Engineering

The purpose of this project was to improve the existing High Temperature Filter Test Unit (HTTU) by optimizing performance and adding new features. These features include viewing ports and a camera system for observation of tests, a leak detection system, and a flame impingement system. Additional considerations included improving the current operation of the HTTU by reducing test time and energy loss. The HTTU is designed to test High Efficiency Particulate Air (HEPA) filters at temperatures up to 1300 ˚F, creating conditions which simulate a fire in a chemical processing facility. The HTTU was originally built as a Cal Poly …

Rapid Tool Heating, Jason Chi, Bobby Dodge

Mechanical Engineering

Quatro Composites creates various molded parts for an array of industries. They are seeking to improve their thermoplastic molding process by decreasing the amount of time to heat up the steel tool that molds the thermoplastics. Currently, it takes approximately 1 hour to heat up their 120 pound steel mold from room temperature to approximately 700°F. The goal of this project is to create an optimum heating method that will minimize that heating time to about 20 minutes or less. It is critical for the stakeholders (Quatro Composites) to have a faster heating time in order to increase their production …

Lunalight - Bringing Light To The Expanding World, Gabriela M. Igel, Daniel J. Patrick, Kimberley M. Smith

Materials Engineering

The LunaLight, a solar rechargeable light and cell phone charger, addresses the lack of access to electricity faced by 1.4 billion of the world’s population (International Finance Corporation). The LunaTech team has developed a product that is bright, simple, compact, versatile and competitive with existing products. Through a partnership with the non-profit organization One Million Lights, LunaTech has improved a previous team’s design to address user feedback, concerns of durability, and manufacturability.

The LunaLight design includes a 5 component plastic housing held together by 4 screws, a surface mounted PCB, a lithium-ion (Li-Ion) battery, one high-brightness LED, a solar panel, …

Ramjet Combustion Chamber, Paul Cameron Stone

Aerospace Engineering

A ramjet combustion chamber is designed and some initial assembly fabrication and test completed as a component of a ramjet graduate project for California Polytechnic State University, San Luis Obispo Supersonic Wind Tunnel. The combustor design is driven by a theoretical model created by a Cal Poly graduate student, Harrison Sykes. Temperature, pressure, and fuel flow will be measured.

Rocket Fuel Pressurization, Sean Green, Joe Marcinkowski, Andrew Nahab

Mechanical Engineering

No abstract provided.

Barbeque Grill Temperature Distribution Design Improvement, Peter Gobell, Connor Mcgill, Thomas Willson

Mechanical Engineering

Team License to Grill set out to asses Bull Outdoor Products, Inc.’s barbeques and quantify the apparent uneven temperature distribution or “hot spots” and “cold spots” across the grill. This testing was accomplished with the design and fabrication of a test fixture allowing for accurate and repeatable temperature collection across the barbeque. With results that matched the sponsor’s claims of hot and cold spots, an engineering model was made using heat transfer and thermodynamic equations. Once the model somewhat resembled the experimental data, it was used to suggest different modifications that would allow for better temperature distribution. It was discovered …

Sustainable Design Retrofit For The Visitor Center At The Oak Ridge National Laboratory, Michael A. Kerksick

Chancellor’s Honors Program Projects

No abstract provided.

Direct Measurement Of Through-Plane Thermal Conductivity Of Partially Saturated Fuel Cell Diffusion Media, Guoqing Xu

Masters Theses

Polymer electrolyte fuel cells (PEFCs) are predicted by many as the most feasible alternative to heat engines and for battery replacement in automotive, portable, and stationary power applications. Fuel cell performance and durability are inseparably related to the presence of liquid water throughout the fuel cell system. To better understand the mechanical and thermal characterization of diffusion media (DM) is essential to PEFC DM design, optimization and production to improve water and thermal managements. Diffusion media are one of the important components in PEFCs in terms of the reactant permeability, the product permeability, the electronic conductivity, the heat conductivity, and …

Water Transport In Polymer Electrolyte Fuel Cells: An Exploration Of Net Water Drag In Real Time, Susan Katherine Reid

Masters Theses

Polymer electrolyte fuel cells (PEFCs) are a promising alternative energy source. One challenge preventing widespread use of this technology is water management. A balance must be reached between providing sufficient water for membrane ionic conductivity while maintaining low enough water content to mitigate the reduction of available reaction sites in the cathode catalyst layer due to liquid water build up. Much exploration of this area of fuel cell research has been conducted, but the details of water transport in an operating fuel cell are not yet fully understood. The motivation of this work was to elucidate mass transport phenomena occurring …

Process-Structure Relationships Of Magnesium Alloys, Arindam Banerjee

Electronic Thesis and Dissertation Repository

This research study characterizes the effects of solidification conditions on the resulting microstructure of an AM60B magnesium alloy during the solidification cycle of the casting. Seventeen control points are chosen from different sections of an instrument panel beam casting and its centerline coordinates are located. These control points locations are then used by Meridian Lightweight Technology Inc. to run a simulation in a MAGMASoft casting software to obtain temperature-time specific data.

An exact analytical solution to the Stefan problem is used to compute the one dimensional heat transfer for a section of the casting and to calculate its temperature distribution …

Computational Analysis To Enhance Laminar Flow Convective Heat Transfer Rate In An Enclosure Using Aerosol Nanofluids, Andrew Hudson

Electronic Theses and Dissertations

The current research intends to provide a starting point to effectively model aerosol heat transfer in a narrow, enclosed body. This research can lead to future modeling of nano fluids including their heat transfer characteristics and erosion effects on the walls of an enclosure. The model was developed using ICEM CFD for the mesh and FLUENT for the fluid flow modeling. Six different aspect ratio enclosures were developed to study the effects of varying aspect ratio. The natural convection of air was developed first to establish the appropriateness of the models being used. A mesh check was performed using one …

Kase, The Laptop Cooling Case, Jana Morrison, Tyler Ries

Biomedical Engineering

This report describes the final design and analysis of a laptop cooling case as a marketable product for a group of entrepreneurial marketing student based out of California Polytechnic State University San Luis Obispo. Background market research and empirical measurements were taken in order to confirm that this would be a marketable product worth designing. Then previous solutions were researched in order to identity weaknesses and strengths. After rigorous research, it was determined that a passive cooling system, in which channels directed airflow to the computer fan would be the best system in terms of functionality, performance, and cost. A …

Design And Testing Of An H2/O2 Predetonator For A Simulated Rotating Detonation Engine Channel, Stephen J. Miller

Theses and Dissertations

A study is presented on the relationship between a pre-detonator and a detonation channel of an RDE. Testing was conducted on a straight narrow channel made of clear polycarbonate windows connected to an H2/O2 pre-detonator to simulate the RDE initiation scheme and allow for flow visualization. A comparison is made on decoupling distance and wave velocities for a range of pre-detonator designs, inclination angles, equivalence ratios and geometries placed within the simulated channel. Regardless of inclination angle or equivalence ratio the detonation wave decoupled within 25 mm from the pre-detonator exit into the channel. A step change in diameter 25 …