Heat Transfer, Combustion Commons^™

Global Time-Resolved Measurements Of Inlet/Isolator Unstart Induced By Mass Injection, Andrew N. Bustard, Benjamin L. Bemis, Aaron Marques, Matthew J. Zahr, Thomas J. Juliano

Publications

The inner surface pressure of an axisymmetric inlet/isolator model was measured using anodized-aluminum pressure-sensitive paint (PSP) viewing through cast acrylic. Temperaturesensitive paint was utilized to correct for the PSP’s temperature sensitivity. The model was tested under Mach 5.7 flow at 𝑹𝒆 = 7.1 ×106 /m under conventional noise conditions. Transverse jet injection with jet-to-inlet mass-flow ratios up to 0.8 was used to induce unstart in the inlet/isolator. Background-oriented schlieren visualization of the inlet shocks was collected simultaneously with the PSP to determine when the inlet unstarted. Computational fluid dynamics results were used to determine off-wall flow structures and quantify approach …

Computational Study Of Rotating Detonation Combustors, Aditya Balasubramaniam

Mechanical and Aerospace Engineering Theses

Rotating detonation combustors (RDCs) are pressure-gain combustion devices that sustain one or more continuously rotating detonation waves, offering potential thermodynamic and performance advantages over conventional deflagration-based systems. Their behavior depends strongly on combustor geometry and operating conditions. Understanding these effects is therefore essential for the design and optimization of practical RDCs. Accordingly, this thesis numerically investigates annular RDCs with two primary objectives: (1) to evaluate the effects of propellant mass flux and (2) to assess the influence of annular width on detonation-wave dynamics and combustor performance.

A finite-volume framework is used to solve the compressible reactive Euler equations with hydrogen–air …

The Spice (Sustainable, Physics-Inspired Culinary Education) Lab – A Digestible Few-Nexus Educational Platform, Carla Ramsdell

National Collaborative for Research on Food, Energy, and Water Education (NC-FEW)

The SPICE (Sustainable, Physics-Inspired Culinary Education) Lab is a unique educational platform that enables participants from a wide disciplinary background to engage and become literate in the unique connections between food, energy and water. This small but mighty space allows for outreach education in many formats, including formal college courses, university-centered hands-on activities and public outreach.

The work performed in this space fills a unique need in the FEW-Nexus education opportunities because it is adaptable to many learners and learning opportunities and its focus on kitchen science makes these concepts approachable which can later be expanded to understand other critical …

Focused Led Sintering, Dylan Defazio, Nilav Maulik, Branden Majors, Michael Fontillas

Mechanical Engineering

This report provides a detailed overview of the final design of our light-emitting diode (LED) focusing system. Our system incorporates a converging lens and a specially designed "glass funnel," which acts as a thick fiber optic that narrows the light to a fine point through internal reflection. The glass components of our system are precisely housed in a part made using advanced computer-numeric controlled (CNC) Mill and CNC Lathe manufacturing processes. This ensures high precision and durability of the overall system. Our LED focusing system is designed with a 60-watt stage light. The decision to use a glass funnel as …

Numerical Simulation Of Laser Induced Elastic Waves In Response To Short And Ultrashort Laser Pulses., Alireza Zarei

All Dissertations

In an era of intensified market competition, the demand for cost-effective, high-quality, high-performance, and reliable products continues to rise. Meeting this demand necessitates the mass production of premium products through the integration of cutting-edge technologies and advanced materials while ensuring their integrity and safety. In this context, Nondestructive Testing (NDT) techniques emerge as indispensable tools for guaranteeing the integrity, reliability, and safety of products across diverse industries.

Various NDT techniques, including ultrasonic testing, computed tomography, thermography, and acoustic emissions, have long served as cornerstones for inspecting materials and structures. Among these, ultrasonic testing stands out as the most prevalent method, …

Measuring Soot In A Novel Configuration For Diffusion Flames Fueled By Ethylene Doped With Iso-Dodecane, Christian Bjork

Honors Scholar Theses

Sustainable Aviation Fuels (SAFs) are seen as the path forward for decarbonizing hard-to-electrify sectors. Using SAFs over traditional fossil fuels abates carbon dioxide emissions but still may present soot emission problems. A milestone in the abatement of soot would be understating its formation mechanisms.

This study aims to quantify soot products resulting from an ethylene flame doped with iso-dodecane, a surrogate SAF component. The burner selected for the investigation is the novel Planar Mixing Layer Flame (PMLF) which allows the tracking of soot formation with the height above the burner (HAB) in a stable diffusion flame. A baseline ethylene-fueled flame …

Thermal Performance Investigation Of Thermoelectric Cooling System With Various Hot-Side Cooling Methods, Bowo Y. Prasetyo, Parisya P. Rosulindo, Fujen Wang

Makara Journal of Technology

Thermoelectric devices have been widely used in various applications, including cooling and power generation. The potential application of thermoelectric cooling systems has been studied. However, these systems still face challenges in achieving optimal performance compared with other cooling systems. Several factors, including the hot-side cooling method, influence the performance of thermoelectric systems. This study aimed to investigate the effects of different hot-side cooling methods on the thermoelectric performance and thermal behavior of thermoelectric cooling systems. The testing methods involved the combination of the thermoelectric module with five hot-side heat exchangers, including a square heatsink, a round heatsink, a two-pipe heat …

Radiative Cooling For Energy-Efficient Power Generation, Rickia Hanna

Celebrating Scholarship and Creativity Day (2018-)

This thesis examined radiative cooling on a small scale using a hybrid photovoltaic/radiative cooling model system, to determine its efficiency for large-scale power generation. Radiative cooling is concerned with heat transfer and this thesis’s main goal is to harness that heat energy to produce electricity. The efficiency of the system was tested using various light sources at different angles and total power output. The testing was done several times and there proved to be a proportional relationship between light intensity and current output. However, due to the performance threshold of the PTEC module, the component of the system used to …

Development Of On-The-Fly Quasi-Steady State Approximation For Chemical Kinetics In Cfd, Abhinav Balamurugan

Doctoral Dissertations and Master's Theses

This study analyzes the feasibility of On-The-Fly Quasi-Steady-State Approximation (OTF-QSSA) application for solving chemical kinetics within Computational Fluid Dynamics (CFD) simulations, aiming to reduce the computational demand of detailed mechanisms. An algorithm that dynamically identifies and designates Quasi-Steady-State (QSS) species at specific grid locations and instances during the simulation was developed. With this information, our method pseudo-delays the advancement of concentrations for these QSS species—effectively setting their rate of concentration change to zero for a set number iteration before updating using the detailed mechanism and thereby omitting the computationally intensive processes typically required for their calculation during those skipped iteration. …

Impact Of Spallation And Internal Radiation On Fibrous Ablative Materials, Raghava Sai Chaitanya Davuluri

Theses and Dissertations--Mechanical and Aerospace Engineering

Space vehicles are equipped with Thermal Protection Systems (TPS) that encounter high heat rates and protect the payload while entering a planetary atmosphere. For most missions that interest NASA, ablative materials are used as TPS. These materials undergo several mass and energy transfer mechanisms to absorb intense heat. The size and construction of the TPS are based on the composition of the planetary atmosphere and the impact of various ablative mechanisms on the flow field and the material. Therefore, it is essential to quantify the rates of different ablative phenomena to model TPS accurately. In this work, the impact of …

Analytical Heat Transfer Modeling Of The Microwave Heating Process: A Focus On Carbon Black, Craig Offutt

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electronic waste (e-waste) has become a significant environmental issue due to the rapid advancement of technology, increasing demand for electronic devices, and shorter lifespan of electronics. One critical step in processing the e-waste involves ball milling as a means of preparing the recycling e-waste for the recovery of critical materials. Ball milling is a technique that involves the mechanical crushing and grinding of electronic waste to reduce its size and improve its reactivity during recovery. Our focused recovery technique is based on a microwave recovery technique of these critical materials from e-waste. The size and distribution of the e-waste with …

Solid Thermal Storage As An Energy Storage Device In Insulated Solar Electric Cookers: Thermal Modeling And Experiment, Michael Antonio Fernandez

Physics

The use of solid thermal storage (STS) as an energy storage device in insulated solar electric cookers (ISEC) was explored using a thermal simulation before retrofitting an existing cooker without energy storage and testing it under several conditions. STS sizing, material selection, and geometry were examined from both theoretical and practical perspectives and re-examined following experimental results. Characterization of the system’s thermal interfaces and methods to improve their thermal conductivities were investigated resulting in several performance enhancements to the system.

Droplet-Based Fuel Property Measurements, Wanjun Dang

LSU Doctoral Dissertations

Ongoing work to find renewable biofuels to function as drop-in replacements or blending components with gasoline has identified a large number of fuel candidates. Given the vast number of potential biomass-derived fuel molecules and limited sample sizes, screening tools are required to down-select candidate fuels having desired physical properties to ensure good engine performance. This work investigates approaches for rapid screening of candidate fuels using micro-liter sample sizes targeting four properties -- surface tension, viscosity, heat of vaporization (HOV), and vapor pressure. Measurement techniques for fuel properties are developed based on unit phenomena for liquid fuel droplets including droplet oscillation …

Investigation Of Two-Phase Flow Phenomena In Rotating Paper Dryer To Achieve Effective Heat Transfer With Low Energy Consumption, Hamed Abdul Majeed

LSU New Orleans Theses and Dissertations

The paper industry provides important consumer products comprised of paper, tissue, paper board, and pulping. The papermaking process requires a lot of energy, in the form of steam, to dry the paper web in rotating dryers. As steam condenses inside the dryers by releasing heat to the dryer walls, the condensate is removed using either stationary or rotary siphons. Since the condensate is usually at a saturated state, part of the condensate flashes into vapor during the extraction process and becomes difficult to extract. Thus, additional blow-through steam is used to push the condensate out. Since this blow-through steam is …

Relationship Between Thermal Conductivity And Free Electrons In Metal, Yansong Liu

Senior Theses

An experiment was designed and conducted to explore the relationship between thermal conductivity with free electrons in metal. In the experiment, copper, iron, aluminum, and titanium rods with close diameters were used to carry out the experiment. Each rod was heated up by a heat unit at one end while cooled on the other end with a heat sink to maintain a steady state. DC current was applied to rods in the direction along, as well as against, the heat flow. Thermal conductivities were measured in these two situations for each rod. Results showed electrons do dominate thermal flow inside …

Numerical Reconstruction Of Spalled Particle Trajectories In An Arc-Jet Environment, Raghava S. C. Davuluri, Sean C. C. Bailey, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

To evaluate the effects of spallation on ablative material, it is necessary to evaluate the mass loss. To do so, a Lagrangian particle trajectory code is used to reconstruct trajectories that match the experimental data for all kinematic parameters. The results from spallation experiments conducted at the NASA HYMETS facility over a wedge sample were used. A data-driven adaptive methodology was used to adapts the ejection parameters until the numerical trajectory matches the experimental data. The preliminary reconstruction results show that the size of the particles seemed to be correlated with the location of the ejection event. The size of …

Multiscale Investigation Of Dropwise Condensation On A Smooth Hydrophilic Surface, Shahab Bayani Ahangar

Dissertations, Master's Theses and Master's Reports

The objective of this work is to identify the fundamental mechanism of dropwise condensation on a smooth solid surface by probing the solid-vapor interface during phase-change to evaluate the existence and structure of the thin film and the initial nucleus that develop during condensation. In this work, an automated Surface Plasmon Resonance imaging (SPRi) instrument with the ability to perform imaging in intensity modulation and angular modulation is developed. The SPRi instrument is used to probe (in three dimensions) the adsorbed film that forms on the substrate during dropwise condensation. SPRi with a lateral resolution of ~ 4-10 μm, thickness …

Thermo-Fluid Characterizations Of The Powder-Bed Fusion Additive Manufacturing Processes Using Laser And Electron Beam, M Shafiqur Rahman

LSU New Orleans Theses and Dissertations

The powder-bed fusion (PBF) process is a subdivision of Additive Manufacturing (AM) technology where a heat source at a controlled speed selectively fuses regions of a powder-bed material to form three-dimensional (3-D) parts. Two of the most effective PBF processes are selective laser melting (SLM) and electron beam additive manufacturing (EBAM), which can fabricate full-density metallic parts in a layer-by-layer fashion. In this study, thermal behavior and melt-pool dynamics in the PBF process are investigated by developing 3-D multiphysics-based thermo-fluid models for both SLM and EBAM, containing Ti-6Al-4V alloy as a powder-bed material. The laser and electron beams are modeled …

Cooking Systems Using Aluminum Foam, Ryan Tetsuo Mizukami

Physics

In developing countries, the use of wood burning fires for cooking is cause for illness and death. With this in mind, research was conducted to develop a solar cooking device capable of cooking of soup within 15 mins in order to reduce the negative impacts of cooking with wood. Current methods of solar-based cooking, such as solar concentrators and solar tube ovens, are impractical. A small solar panel is a cost-effective way to produce energy but will not produce enough power to cook within a reasonable amount of time. Even if it is assumed that all of the energy produced …

Study Of Heat And Momentum Transfer To Colloidal Suspensions In Annular Closed Conduit Flow, Sadik Shoaib

Student Works (2020-2029)

With the advancement of science and the rapid growth of industries and the improved lifestyles of people, energy consumption has been increasing. Whereas the exploration of energy remained at a slower pace and the energy reservoirs are extinguishing at a faster rate. High energy consumption is also encouraging environmental pollution and global warming. Considering all these issues, scientists and engineers are desperately exploring highly efficient heat exchangers for the conservation of energy and minimize its losses. The present research has focused on obtaining highly efficient heat exchangers. Lots of research have performed on the improvement of heat exchanger materials, alteration …

Synthesis Of Eco-Friendly Nanofluids For Enhancement Of Heat Transfer And Application In Different Flow Configuration Passages, Khan Asif

Student Works (2020-2029)

Since the invention of the heat exchangers, the working fluids such as water, ethyl glycol, oil and many others were used, however, they reveal relatively low thermal conductivity. Eco-friendly nanofluids and the cost-effective annular heat exchangers were introduced in this research to overcome the problem. In the present work, heat transfer coefficient and friction loss analyses of (TiO2 and GNP) water-based nanofluids were compared with DI-water flowing in annular conduit under turbulent flow regime. The nanoparticle weight concentrations of 0.1, 0.075, 0.05 and 0.025 wt.% were prepared by using a simple two-step method. The DI-water simulations were conducted by using …

Computational Analysis Of A New Planar Mixing Layer Flame Configuration To Study Soot Inception, Carmen Ciardiello

Honors Scholar Theses

The production of soot is omnipresent in society today. Soot is the product of many of the combustion processes that provide the bulk of the usable energy throughout the world. Furthermore, soot particulate poses a great danger to both the environment and all forms of life on Earth. It has proven to pollute ecosystems, foster health problems for human beings, and degrade air quality [1].

These dangers make studying and understanding soot particulate paramount for improving the quality of life. Thus, this study introduces a new flame configuration for studying soot inception. Presently, various common flame configurations have been found …

Computational Studies Of Thermal Properties And Desalination Performance Of Low-Dimensional Materials, Yang Hong

Department of Chemistry: Dissertations, Theses, and Student Research

During the last 30 years, microelectronic devices have been continuously designed and developed with smaller size and yet more functionalities. Today, hundreds of millions of transistors and complementary metal-oxide-semiconductor cells can be designed and integrated on a single microchip through 3D packaging and chip stacking technology. A large amount of heat will be generated in a limited space during the operation of microchips. Moreover, there is a high possibility of hot spots due to non-uniform integrated circuit design patterns as some core parts of a microchip work harder than other memory parts. This issue becomes acute as stacked microchips get …

Examination Of Flow Dynamics And Passive Cooling In An Ultra Compact Combustor, Tylor C. Rathsack

Theses and Dissertations

The Ultra Compact Combustor (UCC) promises to greatly reduce the size of a gas turbine engine’s combustor by altering the manner in which fuel is burnt. Differing from the common axial flow combustor, the UCC utilizes a rotating flow, coaxial to the engine’s primary axis, in an outboard circumferential cavity as the primary combustion zone. The present study investigates two key UCC facets required to further this combustor design. The first area of investigation is cooling of the Hybrid Guide Vane (HGV). This UCC specific hardware acts as a combustor center body that alters the exit flow angle and acts …

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 …

A Physics-Based Approach To Modeling Wildland Fire Spread Through Porous Fuel Beds, Tingting Tang

Theses and Dissertations--Mechanical and Aerospace Engineering

Wildfires are becoming increasingly erratic nowadays at least in part because of climate change. CFD (computational fluid dynamics)-based models with the potential of simulating extreme behaviors are gaining increasing attention as a means to predict such behavior in order to aid firefighting efforts. This dissertation describes a wildfire model based on the current understanding of wildfire physics. The model includes physics of turbulence, inhomogeneous porous fuel beds, heat release, ignition, and firebrands. A discrete dynamical system for flow in porous media is derived and incorporated into the subgrid-scale model for synthetic-velocity large-eddy simulation (LES), and a general porosity-permeability model is …

Effect Of Spalled Particles Thermal Degradation On A Hypersonic Flow Field Environment, Raghava S. C. Davuluri, Huaibao Zhang, Alexandre Martin

Mechanical Engineering Faculty Publications

Two-way coupling is performed between a spallation code and a hypersonic aerothermodynamics CFD solver to evaluate the effect of spalled particles on the flow field. Time accurate solutions are computed in argon and air flow fields. A single particle simulations and multiple particles simulations are performed and studied. The results show that the carbon vapor released by spalled particles tend to change the composition of the flow field, particularly the upstream region of the shock.

An Assessment Of The Validity Of The Kinetic Model For Liquid-Vapor Phase Change By Examining Cryogenic Propellants, Kishan Bellur

Dissertations, Master's Theses and Master's Reports

Evaporation is ubiquitous in nature and occurs even in a microgravity space envi- ronment. Long term space missions require storage of cryogenic propellents and an accurate prediction of phase change rates. Kinetic theory has been used to model and predict evaporation rates for over a century but the reported values of accommodation coefficients are highly inconsistent and no accurate data is available for cryogens. The proposed study involves a combined experimental and computational approach to ex- tract the accommodation coefficients. Neutron imaging is used as the visualization technique due to the difference in attenuation between the cryogen and the metallic …

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.

Singular Superposition/Boundary Element Method For Reconstruction Of Multi-Dimensional Heat Flux Distributions With Application To Film Cooling Holes, Mahmood Silieti, Eduardo Divo, Alain J. Kassab

Publications

A hybrid singularity superposition/boundary element-based inverse problem method for the reconstruction of multi-dimensional heat flux distributions is developed. Cauchy conditions are imposed at exposed surfaces that are readily reached for measurements while convective boundary conditions are unknown at surfaces that are not amenable to measurements such as the walls of the cooling holes. The purpose of the inverse analysis is to determine the heat flux distribution along cooling hole surfaces. This is accomplished in an iterative process by distributing a set of singularities (sinks) inside the physical boundaries of the cooling hole (usually along cooling hole centerline) with a given …