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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"Hydrogen combustion"”.
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Exploring chemical reaction complexity : application to hydrogen combustion
The aim of this research is to gain insight into hydrogen combustion as a prototype of complex chemistry via classical molecular dynamics (CMD) simulations given the presently available reactive force field, ReaxFF. We focus on developing computational and theoretical methods to analyze CMD …
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Exergetic Analysis Of Hydrogen Combustion Involving Electronically Excited Species
<p>Plasma-assisted combustion (PAC) is a growing field of research that involves using nonthermal plasma (NTP) to enhance combustion. PAC research involves modeling reaction mechanisms and chemical kinetics. Exergy analysis of combustion devices focuses on combustion irreversibility, including …
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An Investigation of Lean Premixed Hydrogen Combustion in a Gas Turbine Engine
… about the carbon emissions associated with the combustion of conventional hydrocarbon fuels, hydrogen is gaining more attention as a clean alternative. The combustion of hydrogen in air produces no carbon emissions. However, hydrogen-air combustion does have the potential to produce oxides of …
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Modelling of Direct Hydrogen Combustion in Jet Engines: System-Level Analysis, Computational Fluid Dynamics and Chemical Reactor Networks
L'abstract è presente nell'allegato / the abstract is in the attachment
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LARGE EDDY SIMULATION OF TURBULENT HYDROGEN FLAMES
Hydrogen is considered a promising energy carrier for low-carbon power generation, especially in gas turbine applications. However, its use introduces important challenges related to flame stability, strong differential diffusion effects, and increased nitrogen oxides (NOx) emissions. These issues …
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Measurement and Analysis of lubricant oil consumption in a single cylinder hydrogen IC engine
… for decades. Lubricant oil consumed in internal combustion engines is a significant contributor to harmful gas and particulate emissions directly threatening the environment and human health. This work focuses on the development and analysis of a direct LOC measurement method of a hydrogen …
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Hydrogen Enrichment Effects on Thermoacoustics of Turbulent Partially Premixed Flames
… decarbonisation targets require incorporation of hydrogen into the existing combustion infrastructure. This doctoral thesis addresses the challenges of hydrogen combustion and thermoacoustic instability in Gas Turbine Model Combustors (GTMC). A bimodal thermoacoustic instability where two …
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Facility and Methodologies for Evaluation of Hydrogen-Air Mixer Performance
… threats to the environment. Lean premixed combustion of hydrogen provides a potential solution to these concerns. A key component of successful lean hydrogen combustion is the fuel-air mixer. A facility and methodology for the evaluation of such a hydrogen-air mixer is developed and …
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A Lean-Premixed Hydrogen Injector with Vane Driven Swirl for Application in Gas Turbines
Hydrogen, as an alternative to conventional aviation fuels, has the potential to increase the efficiency of a gas turbine as well as reduce emissions of greenhouse gases. In addition to significantly reducing the number of pollutants due to the absence of carbon, burning hydrogen at low equivalence …
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Conceptual evaluation of hydrogen hybrid combustion for heavy-duty engines using CFD modelling
Hydrogen is a promising fuel for internal combustion engines (ICEs) due to its combustion properties and potential for zero carbon/low nitrogen oxide emissions. This study investigates a novel hydrogen combustion concept for heavy-duty engines using pre-chamber ignition technology operating in a …
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Acceleration of combustion computation fluid dynamics simulations through machine learning
This work demonstrated the acceleration of combustion computational fluid dynamics simulations through Deep Operator Networks (DeepONets), achieving up to an 18 times speedup in the chemical source term evaluation. Another numerical experiment showed an overall reduction of approximately 30% in …
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Numerical investigation of the combustion of liquid oxygen droplets in an environment of hydrogen under microgravity conditions
… liquid oxygen droplet surrounded by gaseous hydrogen diluted with helium. A numerical model using OpenFOAM as well as a coupled droplet evaporation model based on combining OpenFOAM results with the existing theoretical models have been developed to understand the species and temperature …
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Plasma-coupled microcombustion
"Microcombustion, releasing the chemical energy in a sub-millimeter scale flame, has the potential to provide a high energy density portable power source. Microburners have not realized this potential because of detrimental thermal and chemical surface effects. Investigation of macro-scale (>mm) …
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Laminar burning velocity of hydrogen and flame structure of related fuels for detailed kinetic model validation
… and the flame structure are common targets for combustion studies aimed at detailed kinetic model development. In the present work, fuels relevant to hydrogen combustion were considered. The laminar burning velocity of rich and lean hydrogen flames was studied experimentally and numerically, …
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Analysis of nitrogen oxide emissions produced during combustion of cracked-ammonia fuels
… global initiative to replace organic fuels with hydrogen. While hydrogen boasts high energy density and zero carbon emissions, it is difficult to store, transport, and utilize directly. Ammonia is a hydrogen-dense chemical that is an excellent hydrogen carrier, thus presenting a means to overcome …
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A study of carbon based materials for energy applications
… It was observed that Pt is active for the hydrogen combustion reaction and Ni has less activity for this purpose.It was not expected in this work that efficient hydrogen transport through the polymer would occur, but that future modification of the internal chemistry of PEN can be developed.
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Analyses of flame response to acoustic forcing in a rocket combustor
High frequency combustion instabilities in liquid propellant rocket engines are spontaneously occurring pressure fluctuations that are coupled with unsteady combustion processes. Under the right conditions the unsteady fluctuations can grow to a point where they affect the operation of the …
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Ignition and hydrodynamic ejections by laser-induced breakdowns
… into engineering applications such as internal combustion engines and supersonic propulsion systems. Direct numerical simulation with five gas models, in conjunction with an energy-deposition model that reproduces key experimental observations, is used to analyze the post-breakdown flow and …
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Development of a high power density combustion system for a silicon micro gas turbine engine
… fabrication, packaging and testing of the first combustion system for a silicon micro heat engine. The design and operation of a microcombustor is fundamentally limited by the chemical reaction times of the fuel, by silicon material and fabrication constraints, and by the inherently non-adiabatic …
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