Open Access. Powered by Scholars. Published by Universities.®

Heat Transfer, Combustion Commons

Open Access. Powered by Scholars. Published by Universities.®

702 Full-Text Articles 1,054 Authors 383,435 Downloads 58 Institutions

All Articles in Heat Transfer, Combustion

Faceted Search

702 full-text articles. Page 2 of 26.

Thermal Removal Of Carbon Dioxide From The Atmosphere: Energy Requirements And Scaling Issues, Ted von Hippel 2018 Embry-Riddle Aeronautical University

Thermal Removal Of Carbon Dioxide From The Atmosphere: Energy Requirements And Scaling Issues, Ted Von Hippel

Publications

I conduct a systems-level study of direct air capture of CO2 using techniques from thermal physics. This system relies on a combination of an efficient heat exchanger, radiative cooling, and refrigeration, all at industrial scale and operated in environments at low ambient temperatures. While technological developments will be required for such a system to operate efficiently, those developments rest on a long history of refrigeration expertise and technology, and they can be developed and tested at modest scale. I estimate that the energy required to remove CO2 via this approach is comparable to direct air capture by other techniques. The ...


Modeling Residual Stress Development In Hybrid Processing By Additive Manufacturing And Laser Shock Peening, Guru Charan Reddy Madireddy 2018 University of Nebraska - Lincoln

Modeling Residual Stress Development In Hybrid Processing By Additive Manufacturing And Laser Shock Peening, Guru Charan Reddy Madireddy

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

The term “hybrid” has been widely applied to many areas of manufacturing. Naturally, that term has found a home in additive manufacturing as well. Hybrid additive manufacturing or hybrid-AM has been used to describe multi-material printing, combined machines (e.g., deposition printing and milling machine center), and combined processes (e.g., printing and interlayer laser re-melting). The capabilities afforded by hybrid-AM are rewriting the design rules for materials and adding a new dimension in the design for additive manufacturing paradigm. This work focuses on hybrid-AM processes, which are defined as the use of additive manufacturing (AM) with one or more ...


Additive Manufacturing Of High Solids Loading Hybrid Rocket Fuel Grains, Stephen P. Johnson 2018 Olivet Nazarene University

Additive Manufacturing Of High Solids Loading Hybrid Rocket Fuel Grains, Stephen P. Johnson

Scholar Week 2016 - present

Hybrid rocket motors offer many of the benefits of both liquid and solid rocket systems. Like liquid engines, hybrid rocket motors are able to be throttled, can be stopped and restarted, and are safer than solid rocket motors since the fuel and oxidizer are in different physical states. Hybrid rocket motors are similar to solid motors in that they are relatively simple and have a high density-specific impulse. One of the major drawbacks of hybrid rocket motors is a slower burning rate than solid rocket motors. Complex port geometries provide greater burning surface area to compensate for lower burning rates ...


Investigating Different Modeling Techniques For Quantifying Heat Transfer Through Building Envelopes, Sodiq Akande 2018 East Tennessee State University

Investigating Different Modeling Techniques For Quantifying Heat Transfer Through Building Envelopes, Sodiq Akande

Appalachian Student Research Forum

There is interest concerning the energy performance of buildings in the United States. Buildings, whether residential, commercial or institutional, generally underperform in terms of energy efficiency when compared to buildings that are constructed following sustainably and energy efficiency standards. A substantial percentage of energy loss in these buildings is associated with the thermal efficiency of its envelope (exterior walls, windows roof, floors and doors). The objective of this study will evaluate the results of three energy modeling techniques developed to investigate the energy transfer through the envelope of existing campus buildings. The techniques employed are solving the heat transfer calculations ...


An Evaluation Of Induction Heating In Healthcare Food Industry, Barrett Alexander Hampton 2018 Western Kentucky University

An Evaluation Of Induction Heating In Healthcare Food Industry, Barrett Alexander Hampton

Masters Theses & Specialist Projects

This thesis addresses the problem healthcare facilities are having in maintaining proper food temperatures while transporting meals to patients after food has left the kitchen area. Induction heat has been a known method for generating heat for many years. The commercial food industry currently uses this technology, which is beginning to appear in the residential sector as well because of developments made by manufacturers. This study focuses on the top commercial brand models of induction heaters and the supporting materials currently used to create heat sources to maintain food temperatures in hospitals and long term care facilities.

The research in ...


Multicomponent Working Fluids In Organic Rankine Cycle Evaporators, Jennifer Fromm 2018 Union College

Multicomponent Working Fluids In Organic Rankine Cycle Evaporators, Jennifer Fromm

Honors Theses

Organic Rankine cycles are a promising technology to convert waste heat energy into usable mechanical or electric power, giving them the potential to reduce fossil fuel emissions generated by traditional energy generation. The heat exchangers of these devices are of particular interest, as maximizing energy extraction from these free heat sources will increase net electrical power output. For this project I created a model to predict the effects of mixture working fluids on the evaporator performance of an organic Rankine cycle generator for a wide range of waste heat source temperatures. This model combines empirically derived heat exchanger performance parameters ...


Investigation On The Potential Of A Co2 Capture System, Downstream Of The Aftertreatment System For A Heavy-Duty Engine Application, Murchana Pathak 2018 Michigan Technological University

Investigation On The Potential Of A Co2 Capture System, Downstream Of The Aftertreatment System For A Heavy-Duty Engine Application, Murchana Pathak

Dissertations, Master's Theses and Master's Reports

The transportation sector accounts for the second largest source of CO2 emissions after power generation. New Corporate Average Fuel Economy (CAFE) regulations are focusing on improving energy through reduced fuel consumption and greenhouse gas emissions. This work investigates the potential of a CO2 capture system downstream of an aftertreatment system for a heavy-duty engine application. Amine absorption has been described as one of the most effective ways to capture CO2 from the exhaust for point sources. Therefore, using thermal-swing absorption process with potassium carbonate (K2CO3) as the absorbent liquid, a process was analyzed for ...


An Experimental And Computational Study Of Fuel Spray Interaction: Fundamentals And Engine Applications, Le Zhao 2018 Michigan Technological University

An Experimental And Computational Study Of Fuel Spray Interaction: Fundamentals And Engine Applications, Le Zhao

Dissertations, Master's Theses and Master's Reports

An efficient spray injection results in better vaporization and air-fuel mixing, leading to combustion stability and reduction of emissions in the internal combustion (IC) engines. The impingement of liquid fuels on chamber wall or piston surface in IC engines is a common phenomenon and fuel film formed in the spray-piston or cylinder wall impingement plays a critical role in engine performance and emissions. Therefore, the study of the spray impingement on the chamber wall or position surface is necessary.

To understand the spray-wall interaction, a single droplet impingement on a solid surface with different conditions was first examined. The droplet-wall ...


Characterization Of Methane-Air Diffusion Flames For Flame Synthesis Application Through Optical Diagnostics, Zhaojin Diao 2018 University of Kentucky

Characterization Of Methane-Air Diffusion Flames For Flame Synthesis Application Through Optical Diagnostics, Zhaojin Diao

Theses and Dissertations--Mechanical Engineering

Flame synthesis is a growing field of research aiming at forming new materials and coatings through injection of seed materials into a flame. Accurate prediction of the thermal structure of these flames requires detailed information on the radiative properties and a thorough understanding of the governing combustion processes. The objective of this work is to establish a basic optical diagnostic characterization of different methane-air diffusion flames of different complexity. The basic principles are developed and demonstrated at a rotational symmetric co-flow burner and finally applied to a burner consisting of six clustered microflames which is designed for future flame synthesis ...


Effects Of Air-Fuel Ratio And Operating Conditions On Particle Emissions From A Small Diesel Engine, Odinmma John-Paul Ofili 2018 Bucknell University

Effects Of Air-Fuel Ratio And Operating Conditions On Particle Emissions From A Small Diesel Engine, Odinmma John-Paul Ofili

Master’s Theses

Automotive engineers typically increase the air-fuel ratio (AFR) of an engine to control the amount of smoke emitted, but it not quite known how this process affects particulate number (PN). In the work presented, AFR was independently varied to study its effects on PN. It was found that increasing the AFR reduced the concentrations of larger particles from 108 #/cm3 to 106 #/cm3 which is an effect observable as a reduction in smoke. However, the same increases in AFR only resulted in an energy specific PN change from 1015 #/kWh to 1014 #/kWh. The ...


Laminar And Turbulent Study Of Combustion In Stratified Environments Using Laser Based Measurements, Stephen William Grib 2018 University of Kentucky

Laminar And Turbulent Study Of Combustion In Stratified Environments Using Laser Based Measurements, Stephen William Grib

Theses and Dissertations--Mechanical Engineering

Practical gas turbine engine combustors create extremely non-uniform flowfields, which are highly stratified making it imperative that similar environments are well understood. Laser diagnostics were utilized in a variety of stratified environments, which led to temperature or chemical composition gradients, to better understand autoignition, extinction, and flame stability behavior. This work ranged from laminar and steady flames to turbulent flame studies in which time resolved measurements were used.

Edge flames, formed in the presence of species stratification, were studied by first developing a simple measurement technique which is capable of estimating an important quantity for edge flames, the advective heat ...


NoX Formation In Light-Hydrocarbon, Premixed Flames, Robert T. Hughes 2018 University of Kentucky

NoX Formation In Light-Hydrocarbon, Premixed Flames, Robert T. Hughes

Theses and Dissertations--Mechanical Engineering

This study explores the reactions and related species of NOx pollutants in methane flames in order to understand their production and consumption during the combustion process. To do this, several analytical simulations were run to explore the behavior of nitrogen species in the pre-flame, post- flame, and reaction layer regions. The results were then analyzed in order to identify all "steady-state" species in the flame as well as the determine all the unnecessary reactions and species that are not required to meet a defined accuracy. The reductions were then applied and proven to be viable.


Heat Transfer Vest, Nicholas Forsgaard 2018 Central Washington University

Heat Transfer Vest, Nicholas Forsgaard

All Undergraduate Projects

The purpose of this report is to document the progression of the authors senior project. . The of that project was the research of Liquid Cooled Garment (LCG) technology, the generation of a novel LCG prototype and the testing of that prototype relative to a commercial benchmark. As such, this report is a complete narrative of the of these tasks, their execution and the underlying assumptions and commentary. The motivation for this report is to satisfy the capstone requirements of the MET program at CWU by documenting the Senior Project and its subordinate tasks. First, the student designed a LCG system ...


Pyrolysis Of Fiber-Plastic Waste Blends, Shreyas Kolapkar 2018 Michigan Technological University

Pyrolysis Of Fiber-Plastic Waste Blends, Shreyas Kolapkar

Dissertations, Master's Theses and Master's Reports

The main objective of this work is to investigate fast pyrolysis of fiber and plastic feedstocks in order to understand the synergistic effect from their co-pyrolysis. In this on-going work, fiber, plastic and their blend are characterized and pyrolysis oil is produced from them in the fast batch pyrolysis reactor. Based on a heat transfer model it is shown that results of oil produced from batch reactor will be applicable to the continuous paddle reactor. From feedstock characterization, chlorine was observed particularly in the plastic feedstock. Thus, chlorine removal method using torrefaction and high shear mixing was implemented and was ...


Thermomagnetic Convective Cooling Of Hall Effect Thruster, Elizabeth M. Vanheusden 2018 Michigan Technological University

Thermomagnetic Convective Cooling Of Hall Effect Thruster, Elizabeth M. Vanheusden

Dissertations, Master's Theses and Master's Reports

This work proposes and shows that thermomagnetic convection could be used in zero gravity to cool components of a Hall-effect thruster. A ferrofluid cavity was develop in the thermal and geometric model of a Hall-effect thruster. Simulations show that with an Ionic Liquid Ferrofluid after two minutes of thruster operations thermomagnetic convection occurs and in zero gravity will produce a larger velocity then natural convection that occurs in earth gravity. However, experiments did not result in heat transfer enhancement due to the limitation of the ferrofluid. Replacement of the Ferrotec EFH1 dispersant with dodecylbenzene did not result in Ionic Liquid ...


A New Technique To Determine Accommodation Coefficients Of Cryogenic Propellants, Kishan Bellur 2018 Michigan Technological University

A New Technique To Determine Accommodation Coefficients Of Cryogenic Propellants, Kishan Bellur

Dissertations, Master's Theses and Master's Reports

The control of propellant boil-off is essential in long-term space missions. However, a clear understanding of cryogenic propellant phase change and the values of accommodation coefficients are lacking. To that effect, a new method to determine accommodation coefficients using a combination of neutron imaging, thin film evaporation modeling and CFD modeling has been established. Phase change experiments were conducted in the BT-2 Neutron Imaging Facility at the National Institute of Standards and Technology (NIST) by introducing cryogenic vapor (H2 and CH4) at a set pressure into Al6061 and SS316L test cells placed inside a 70mm cryostat. Condensation is achieved by ...


The Kentucky Re-Entry Universal Payload System (Krups): Sub-Orbital Flights, James Devin Sparks 2018 University of Kentucky

The Kentucky Re-Entry Universal Payload System (Krups): Sub-Orbital Flights, James Devin Sparks

Theses and Dissertations--Mechanical Engineering

The Kentucky Re-entry Universal Payload System (KRUPS) is an adaptable testbed for atmosphere entry science experiments, with an initial application to thermal protection systems (TPS). Because of the uniqueness of atmospheric entry conditions that ground testing is unable to replicate, scientists principally rely on numerical models for predicting entry conditions. The KRUPS spacecraft, developed at the University of Kentucky, provides an inexpensive means of obtaining validation data to verify and improve these models.

To increase the technology readiness level (TRL) of the spacecraft, two sub-orbital missions were developed. The first mission, KUDOS, launched August 13th, 2017 on a Terrier-Improved Malamute ...


Spacecraft Fire Safety Research: Combustion Of Lithium-Ion Batteries To Predict Fire Scenarios, Elisabeth Meyer 2018 The University of Akron

Spacecraft Fire Safety Research: Combustion Of Lithium-Ion Batteries To Predict Fire Scenarios, Elisabeth Meyer

Honors Research Projects

The purpose of this project was to research characteristics of a Lithium-ion battery fire to determine if trends exist in measured fire characteristics that can help predict different fire scenarios. These experiments will ultimately aid in developing an alarm threshold for a spacecraft smoke detector, specifically for Orion, a new, multi-purpose crew vehicle under development by NASA. Orion is the next-generation of spacecraft designed to replace the space shuttle and will play an important role in NASA’s journey to Mars.

In the experiments performed, Lithium-ion batteries were placed in a test chamber and ignited while smoke concentration was measured ...


Ignition Studies Of Oxy-Syngas/Co2 Mixtures Using Shock Tube For Cleaner Combustion Engines, Samuel Barak 2018 University of Central Florida

Ignition Studies Of Oxy-Syngas/Co2 Mixtures Using Shock Tube For Cleaner Combustion Engines, Samuel Barak

Electronic Theses and Dissertations

In this study, syngas combustion was investigated behind reflected shock waves in order to gain insight into the behavior of ignition delay times and effects of the CO2 dilution. Pressure and light emissions time-histories measurements were taken at a 2 cm axial location away from the end wall. High-speed visualization of the experiments from the end wall was also conducted. Oxy-syngas mixtures that were tested in the shock tube were diluted with CO2 fractions ranging from 60% - 85% by volume. A 10% fuel concentration was consistently used throughout the experiments. This study looked at the effects of changing the equivalence ...


Computational Exploration Of Flash-Boiling Internal Flow And Near-Nozzle Spray, Sampath K. Rachakonda 2018 University of Massachusetts Amherst

Computational Exploration Of Flash-Boiling Internal Flow And Near-Nozzle Spray, Sampath K. Rachakonda

Doctoral Dissertations

Gasoline engines operating under the principle of direct injection are susceptible to flash-boiling due to superheated nature of the fuel and the sub-atmospheric in-cylinder pressures during injection. A review of the literature on flash-boiling sprays shows that a majority of the studies have focused on the far-field regions of the spray, with limited attention given to understanding the influences of the injector geometry and the near-nozzle regions of the spray. Modeling the internal nozzle flow and the primary atomization, on which the far-field spray depends, is a challenge. This thesis, therefore, is aimed at understanding the complex flow through a ...


Digital Commons powered by bepress