Heat Transfer, Combustion Commons^™

Exploring A Platinum Nanocatalytic Microcombustion-Thermoelectric Coupled Device, Dylan Moore Mcnally

Theses and Dissertations

This work aimed to create a first-generation power device for eventual application to portable electronics. A platinum nanoparticle catalytic substrate was employed in a microcombustion-thermoelectric coupled (MTC) device for the purpose of chemical-to-electrical energy conversion. Multiple microcombustion reactors were designed, fabricated, and investigated. Most importantly, the reactor configuration was designed to accommodate thermoelectric generators (TEGs) for power production. Temperature studies with catalytic combustion of methanol-air fuel mixtures were used to evaluate the thermal power generation performance of each reactor. The final reactor design enabled ignition at room temperature with the ability to achieve repeat catalytic cycles upon subsequent exposure to …

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

University of 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 …

Numerical Evaluation Of Effective Thermal Response Of Heterogeneous Materials, Kevin W. Irick

Mechanical Engineering ETDs

Heterogeneity in materials leads to increased complication of physics, at the level or scale where heterogeneity exists, making analysis and material behavior predictions more difficult. As a result of the intricate descriptions or understanding of the physics required to determine the behavior of a heterogenous material or system, practitioners frequently prefer the use of effective properties or responses. This body of work is dedicated to performing computational analyses on the thermal behavior of heterogeneous materials and evaluating the corresponding analyses using formal verification approaches. Custom finite element method code was used for solving the heat equation in a variety of …

Performance Improvements For Next Generation Falling Particle Receiver Systems, Nathan R. Schroeder

Mechanical Engineering ETDs

Falling particle receiver (FPR) systems are a rapidly developing technology for concentrating solar power applications. Solid particles are used as both the heat transfer fluid and thermal energy storage media. Through the direct solar irradiation of the solid particles, flux and temperature limitations of tube-bundle receives can be overcome leading to higher operating temperatures and energy conversion efficiencies. Particle residence time, curtain opacity, and curtain stability affect the performance of FPR designs. As the particles fall through the receiver the curtain accelerates, increasing its transmissivity thus decreasing the amount of energy absorbed. Multistage release trough structures catch and release the …

Effect Of Adding Palm Fiber To Thermal Conductivity Of Quick Set Concrete, Monica Garcia

Theses and Dissertations

As climate change becomes a more dire issue and more readily accepted by those in power, the demand for local and systemic solutions grows louder. In urban environments, one issue of concern is the contribution of anthropogenic heat from buildings which contributes to localized warming of the environment. A method that can reduce anthropogenic heat is decreasing the thermal conductivity of building materials. The objective of this study is to examine the possibility of using palm fibers to reduce the thermal conductivity of quick-set concrete samples. The data gathered in this study are used to determine the thermal conductivity value …

Heat Transfer Modeling And Optimization Of A Carbonized Microvascular Solar Receiver, Taylor Brown

Boise State University Theses and Dissertations

Concentrating solar power is an emerging renewable energy source. The technology can collect and store thermal energy from the sun over long durations, generating electricity as needed at a later time. Current CSP systems are limited to a maximum operational temperature due to constraints of the working fluid, which limits the maximum possible efficiency of the system. One proposed pathway forward is to utilize a gas phase for the working fluid in the system such as supercritical carbon dioxide.

A composite gas phase modular receiver is being developed by researchers at Boise State University and the University of Tulsa. The …

Molecular Mechanisms And Design Of Hydrogen-Bonded Materials For Thermal Applications, Jinlong He

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heat transfer at the nanoscale plays an important role in determining the reliability and performance of many innovative advanced materials technologies such as nanoelectronics, semiconductor, biomedical devices, polymers, and composites. Extensive efforts have been made to design materials with extraordinary thermal properties. However, fundamental understanding of heat transfer in many of these materials is still not lacking, because the thermal transport processes are governed by several factors including molecular morphology and chemical bonding. Among these factors, the atomic bonding between two dissimilar materials or within single materials is of particular interest due to its ubiquity and importance in physical processes. …

Development Of A Tiny House Design Tool To Increase Safety, Efficiency, And Cost-Effectiveness, Michael Joseph Stratton Ii

Masters Theses

A growing number of people are choosing to live more sustainably, and this is commonly done through living in an extremely small house, also called a “tiny house”. There is no set definition for a tiny house, but it typically refers to a structure less than 500 ft2, sometimes built by the homeowner, and frequently built on a travel trailer.

The popularity of tiny houses has increased over the years due to different television shows, internet videos, and photo sharing websites, but the technical details are rarely covered, which is why this study examines the structural, stability, weight, and thermal …

Modeling, Simulation, And Testing Of Sweeping Convection, Amir Kiaee

Mechanical Engineering Research Theses and Dissertations

In this study, the new convection heat transfer concept of sweeping convection, using large particles flowing with a fluid in a channel, is considered. This novel concept is inspired by the gas exchange process in alveolar capillaries, where red blood cells (RBCs) flow with blood plasma, yielding very high gas transfer efficiency. An important characteristic of alveolar capillary blood flow, believed to be related to the high efficiency of the lungs, is the snug fitting of the RBCs into the capillaries. This tight fitting sets the RBCs (particles) acting like pistons as they flow downstream with the plasma (fluid), facilitating …

Thermal Control Development Of A Proton Exchange Membrane Fuel Cell System, Ola Mohammed Taha Al-Shalash

Mechanical Engineering Theses

A fuel cell is an electrochemical energy conversion device that uses fuel to generate electricity. It basically converts the chemical energy of reactants directly into electricity without combustion. In a Proton Exchange Membrane Fuel Cell (PEMFC), the reactants, hydrogen and oxygen, are fed into the two electrodes, anode and cathode, respectively. A reaction takes place at each electrode and produces electricity, as well as water, and heat as the by-products. In order to maximize performance of a fuel cell, many factors can be considered for tuning and control. Temperature management is one of these factors.

A thermal-fluid model of a …

Potential Energy Generation From Agricultural Residue In Indonesia, Adrian Rizqi Irhamna

International Programs

Indonesia has great potential of biomass sources from their agricultural residue, which can potentially be used for alternative energy generation. This preliminary research explores the most suitable technology for energy generation from agricultural residue and its challenge for application in Indonesia. The study showed that biomass utilization via the direct combustion process is recommended for energy generation. It is also reported that the pretreatment process of drying and washing, are required to increase the fuel quality and plant efficiency.

Study Of Heat Transfer And Friction Loss Of Nanofluid Suspension Flow In Circular Pipe Heat Exchanger, Ramadas Sandru

Student Works (2020-2029)

This stated experiment focused on the study of convective heat transfer and friction loss in a circular flow passage for Graphene oxide-based nanofluids which are consist of Graphene Oxide/Distilled water with their different wt. % concentrations. These GO/DW based nanofluids where been prepared by using a facile two-step method, while the GO particles were synthesized by a modified hummer method. Four different (0.025, 0.05, 0.075, and 0.1 wt. %) were produced by dispersing graphene particles in distilled water under high probe sonication. The GO/DW based nanofluids flowing in a horizontal shell and tube heat exchanger counter flow under turbulent flow …

Kinetic Study Of In-Pipe Water Flow For Power Generation, Surendaran Venuthan

Student Works (2020-2029)

In-pipe turbine generator has a potential to harvest energy from an existing water flow from distribution pipe which have natural and pumping capacity. That flow will be used to convert kinetic energy from the pipe to rotate the turbine. In turn, the turbine may be connected to a generator to produce electric power. The fact that the in-pipe turbine generator will be a useful energy harvesting tool with potential with industrial application is recommended by many scholars. However, there is a concern where there are many types and sizes of pipe that is readily used in the water works industry. …

Cfd Modelling Of Multiphase Flow In Static Mixer, Silverrajan Viknesvaran

Student Works (2020-2029)

Modelling of Multiphase flow through a Kenics static mixer were presented in this paper. Multiphase mixing is a challenging process in industries such as pharmaceutical, food and petroleum since two-different phases can be immiscible towards each other. Stirred tank mixing is the most common method used in industries. However, this type of method costs a lot in terms of energy and manpower specially when mixing immiscible liquids. Hence, The Kenics Static Mixer could be a good solution for multiphase mixing when its correctly configured and studied. Two phases used in this paper were aqueous solution: refined CMC as continuous phase …

Investigations Of Air-Water Multiphase Flow In Tubes: Computational Fluid Dynamics, Wei Hong Goo

Student Works (2020-2029)

Mixing is a very crucial process in many industries, such as food processing industry, minerals processing industry, petrochemicals and refining industry, pulp and paper industry, polymer industry, pharmaceuticals industry and many more. There are different types of mixing, such as liquid-gas mixing, liquid-liquid mixing, solid-liquid mixing and many more. The definition of multiphase flow is the simultaneous flow of materials with multiple thermodynamic phases. A lot of process industries require multiphase flows during operation. Bubbly flow is defined as the flow of liquids that contains dispersed gas bubbles. One of the main applications of multiphases flows and bubbly flows is …

Study Of Heat Transfer And Friction Loss Of Nanofluid Suspension Flow In Square Pipe Heat Exchanger, Krishnan Jayprasanth

Student Works (2020-2029)

An experimentational analysis was done to evaluate heat transfer features of graphene oxide (GO) nanofluid inside the cross section of square cross tube that was exposed to a uniform constant heat flux of the test segments. Lately huge figures of researches have been are proceeded out to examine the outcome of nanofluid in augmentation of the heat transfer rate in numerous heat exchangers particularly using hummer method to attain GO. In this case, advanced hummer method was used to obtain GO and further analyses the effect of the nanofluids. The viscosity and thermal conductivity for the (GO) nanofluids at the …

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 …

What Difference Does A Catalyst Make?, Tammy Guthrie, Mike Jackson, Holly Haney

High School Lesson Plans

Students will use different catalysts for the decomposition of Hydrogen Peroxide, to determine if different catalysts affect the energy that is generated during the reaction.

A Computational Study Of Water Mobility On Smooth Surface, Cavities And Porous Structure With Hydrophilic And Hydrophobic Coatings, Kok Wee Yong

Student Works (2020-2029)

This research focus on water mobility and discovers a new phenomenon where droplet accelerates on a hydrophilic cavity surface when sliding down from a hydrophobic surface. The kinetic energy of droplet increases six (6) times higher than before sliding into the first cavity. This finding is useful for creating an effective way of filling liquids into cavities for passive microfluidics related devices. The work consists of validating cases using Computational Fluid Dynamics (CFD) software. The first part of the research reviews the literature regarding CFD modelling of a water droplet (i) sliding down on a surface, (ii) detachment in a …

Development Of Reduced Chemical Kinetic Models For The Numerical Simulation Of Combustion And Emissions Behavior Of Representative Conventional And Bio-Derived Fuels, Mazen A. Eldeeb

Mineta Transportation Institute

The study addresses two of the main challenges facing combustion modeling for transportation fuels: simultaneous simulation of non-related combustion problems and reducing the computational cost of the modeling process itself. To address the first challenge, researchers determine a characteristic flame time from thermal diffusivity and laminar burning velocity. Researchers examine parametric dependence of flame time and ignition delay time on pressure, temperature and equivalence ratio for methane, based on validated chemical kinetic mechanisms. The study reveals flame time and ignition delay time show similar temperature dependence, flame time has stronger dependence on equivalence ratio and weaker dependence on pressure than …

Design For Additive Manufacturing, Michael Charonnat, Leonardo Franco-Muñoz, Sam Noble, J.P. Purdom

Mechanical Engineering

This document outlines the critical design details and timeline for the Design for Additive Manufacturing Senior Project sponsored by Solar Turbines, Inc. The scope of this project encompasses the redesign of two of Solar Turbine’s cast parts for metal additive manufacturing in order to minimize lead time, cost, and weight. With the overall objective of performing in-depth analysis exploring affordability & feasibility, this redesign process will aid Solar Turbines in expanding their knowledge of Design for Additive Manufacturing principles and enable them to further incorporate the use of additive manufacturing into their production processes. The first part that the team …

Analysis Of Burning Wood In The Transient State And The Application To Structural Design, Roberta Veliz, Kimberly Guzman

Architectural Engineering

Determining the extent of the contribution of exposed timber on compartment fire dynamics in open floor plans is a complex process. Designers traditionally used compartmentalization design methods which create spaces where flashover is likely, given the fuel load and ventilation conditions. However, due to the large geometric dimensions and spread of fuel, fires in open floor plans are more likely to remain as localized or traveling fires. As such, an understanding of not only ignition potential but also flame spread is critical to characterizing the contribution of exposed timber. An integral step in characterizing the potential contribution is through an …

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 …

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 …

Heat Transfer Analysis Of A Data Centre, Arumainathan Kabildev

Student Works (2020-2029)

Data centres are an integral part of networking as it houses servers that facilitate incoming and outgoing data flow. A resolute cooling approach is needed to overcome the hot air dissipated by these servers. This research focused on the computational fluid dynamics (CFD) simulation of the heat transfer modelled upon Telekom Malaysia (TM) City’s data centre 3. The simulation was carried out to ascertain the heat distribution across the data centre by using ANSYS Fluent. The results indicated that the server racks’ inlet temperature reaches 29.79 oC, which is close to the maximum permissible limit according to recommendations provided by …

Raysun's Infrared Raisin Dryer, Lucas Kensinger, Saraith Aispuro, Joe Vanacore

General Engineering

The RaySuns senior project team was tasked with lowering the drying costs of raisins for River Ranch Raisins. In doing so, we explored several options for cutting costs: utilizing automation and exploring new drying technologies were our primary focus. We eventually planned a modular infrared heating mechanism which would be easy to automate in future projects. After manufacturing and testing an infrared heating mechanism, it was found that infrared drying could significantly cut costs versus the previous natural gas fired dryer tunnels while leaving room for automation. The infrared dryer was also shown to have the potential to create high-quality …

The Effect Of Orientation On The Ignition Of Solids, David Morrisset

Master's Theses

The ignition of a solid is an inherently complex phenomenon influenced by heat and mass transport mechanisms that are, even to this day, not understood in entirety. In order to use ignition data in meaningful engineering application, significant simplifications have been made to the theory of ignition. The most common way to classify ignition is the use of material specific parameters such as such as ignition temperature (T_ig) and the critical heat flux for ignition (CHF). These parameters are determined through standardized testing of solid materials – however, the results of these tests are generally used in applications …

Fly Ash Based Geopolymer For High Temperature And High Compressive Strength Applications In Aggressive Environment, Aaryan Manoj Nair, Akm S. Rahman

Publications and Research

Geopolymers are the results of geosynthetic reactions between aluminosilicates and strong bases. This results in chemical bonds between aluminum (Al), Silicon (Si)and oxygen (O) composing polymer rings in tetrahedral coordination. These bonds give them widespread useful applications such as high heat bearing ceramics, and base construction material whilst being far more environmentally conscious. The purpose of the experiment is to examine the effect of Silicon Carbide whisker and inorganic glass particles on thermal and mechanical properties of Geopolymers. This study will help understand the effect of various compositions and concentrations of SiO₂ in mechanical strength. In this experiment, the …

Development And Application Of Elliptic Blending Lag K-Omega Sst Standard And Wall-Distance-Free Turbulence Model, Wenjie Shang

McKelvey School of Engineering Graduate Student Theses & Dissertations

In recent decades, Computational Fluid Dynamics (CFD) has become the most widely used technology to understand the fundamental complex fluid dynamics of turbulent flows as well as for modeling of turbulent flows in industrial applications. In industrial applications, the widely used methodology is to solve Reynolds-Average Navier-Stokes Equations (RANS) equations in conjunction with a turbulence model since it strikes a balance between accuracy and computational cost compared to other high fidelity approaches namely the Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS), There are a large number of turbulence models proposed in past five decades, majority of them are …

A Study Of The Efficiency And Effectiveness Of The First Four Iterations Of Sierpinski Carpet Fractal-Like Fins At Increasing Angles In Natural Convection, Sophia N. Fleri

Honors College Theses

Fractal geometries have been found in several studies to increase a fin’s thermal performance. Both the reductions of volume and mass accompanied by an increase in performance are desirable to prevent malfunction of the device through passive heat dissipation. The Sierpinski carpet fractal pattern, beginning with a basic square geometry in which an increasing number of perforations are incorporated through each successive iteration, reduces the fin’s mass while increasing its surface area simultaneously; this increase in surface area increases the rate of heat transfer experienced across the fin. The first four iterations of the Sierpinski carpet pattern, each with identical …