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Showing 1 to 20 of 236 for “"heat release"”.
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Controlling Object Heat Release Rate using Geometrical Features
… made using additive manufacturing. Controlling heat release rate has applicability in limiting fire hazards as well as for designing fuels for optimal burning rate. The burning rate of a structure is a function of the material properties as well as the airflow through it, which is dictated by …
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Effect of heat release on streamwise vorticity enhanced mixing
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1995.
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Heat release estimation and prediction of Wankel stratified-charge combustion engine
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1985.
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Computational Study of Parameters Affecting Electric Cabinet Fire Heat Release Rate
… cabinet fires, which are quantified as the heat release rate (HRR), and properly categorize them. With this knowledge, optimal parameter-response relationships can be developed to predict the electrical cabinet fire behavior. Statistical analysis conducted in this study on historical fire …
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Experimental Investigation of the Heat Release in a Turbocharged Aftercooled Prechamber Diesel Engine
Made available in DSpace on 2014-12-09T17:13:48Z (GMT). No. of bitstreams: 1 7013257.pdf: 2548507 bytes, checksum: 10db3f00675ccf66f12041cfc0048fd8 (MD5) Previous issue date: 1969
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Reduced-Order Models for the Prediction of Unsteady Heat Release in Acoustically Forced Combustion
This work presents novel formulations for models describing acoustically forced combustion in three disjoint regimes; highly turbulent, laminar, and the moderately turbulent flamelet regime. Particular emphasis is placed on simplification of the models to facilitate analytical solutions while still …
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CO₂ and Heat Release from Magmatic Hydrothermal Systems: Insights from CO₂ Flux and Other Modern Methods
… at the Earth’s surface as areas of steam heated ground. Ground based heat flux and CO2 flux surveys typically result in 100’s or 1000’s of individual flux measurements. These datasets are usually integrated to provide measures of total flow for the surface area under investigation (i.e. …
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Equivalence Ratio Gradient Effects on Local Flame Front Topology and Heat Release Rate in Stratified, Iso-Octane/Air Turbulent V-Flames
… OH and CH2O PLIF images was used as a measure of heat release rate (HRR) and to calculate flame topology data. Results within comparable ROIs were analyzed to elucidate gradient effects, providing several important insights. When comparing consistent ranges of ϕ within an ROI, the mean ϕ gradients …
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The Effects of Porous Inert Media in a Self-Excited Thermoacoustic Instability: A Study of Heat Release and Reduced Order Modelling
… between acoustic pressure and unsteady heat release in a combustor. Thermoacoustic instabilities have been shown to cause structural damage and limit operability of combustors. To mitigate these instabilities, a variety of active and passive methods can be employed. The addition of …
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Vortex driven flame dynamics and combustion instability
… mostly arises due to the coupling between heat release rate dynamics and system acoustics. It is crucial to understand the instability mechanisms to design reliable, high efficiency, low emission gas turbine combustors. In this thesis, elementary processes acting as a source of unsteady …
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A Five-Zone Model for Direct Injection Diesel Combustion
… 3) rich premixed products 4) diffusion flame sheath 5) surrounding bulk gas. Temperature and composition in each zone is calculated. Composition in combusting zones was calculated using an equilibrium model that includes 21 species. Sub models for ignition delay, premixed burn duration, heat …
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Modeling full-scale fire test behaviour of polyurethane foams using cone calorimeter data
… use finer modeling techniques to predict the heat release rate of the specimens, based on information obtained from cone calorimeter tests. Full-scale fire tests of 10 cm thick polyurethane foams of different sizes were conducted using center and edge-ignition locations. Flame spread and heat …
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Carbon Monoxide Generation and Transport from Compartment Fires
… with three different ventilation conditions and heat release rates ranging from 50 kW to 500 kW. The transport study was conducted with a 6.1 m long hallway connected to the compartment in a head-on configuration. All measurements were performed at the compartment or hallway exit plane during the …
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The effect of fuel injection pressure and in cylinder temperature on igniton delay, combustion performance and emission
… during the ignition delay period and initial heat release in combustion process that strongly affects the exhaust emissions. This study investigated effects of ambient temperature,Ti and injection pressure, Pinj on the heat release process during ignition delay periods. Rapid compression …
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Thermoacoustic Analysis and Experimental Validation of Statistically-Based Flame Transfer Function Extracted from Computational Fluid Dynamics
… and sustain due to the coupling of unsteady heat release from the flame and the acoustic field. One potential driving mechanism for these instabilities arise when velocity fluctuations (u') at the fuel injection location causes perturbations in the local equivalence ratio and is convected to …
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Evaluation of a Strut-Plasma Torch Combination as a Supersonic Igniter-Flameholder
… combination was tested in the Virginia Tech unheated supersonic wind tunnel at Mach 2.4. Pressure and temperature sampling, filtered photography, and spectroscopic measurements were used to compare different test cases. These results provide both qualitative and quantitative results on how the …
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A Computational Fluid Dynamics Investigation of Thermoacoustic Instabilities in Premixed Laminar and Turbulent Combustion Systems
… instabilities, which manifest as pressure and heat release oscillations in the combustor. To be able to predict and control these instabilities, it is required that both the acoustics of the system, and a frequency-resolved response of the combustion process to incoming perturbations be …
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Spatially Resolved Analysis of Flame Dynamics for the Prediction of Thermoacoustic Combustion Instabilities
… acoustics and oscillations in the flame heat release rate form a closed feedback loop, through one of two possible mechanisms. The first is direct coupling which occurs due to the mean mass flow oscillations induced by the acoustic velocity. Secondly, the acoustics may couple with the …
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Estimation of the In-Cylinder Air/Fuel Ratio of an Internal Combustion Engine by the Use of Pressure Sensors
… engine. An estimation model which uses the net heat release profile for estimating the cylinder air/fuel ratio of a spark ignition engine is developed. The net heat release profile is computed from the cylinder pressure trace and quantifies the conversion of chemical energy of the reactants in …
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Numerical simulations of experimental results in a power unit to validate the energy output resulting from gas pressurizations on nanoparticles
… recorded by the research group in terms of heat release from pressurizations of specific nanoparticles of alloys by Hydrogen. The number of unknowns was an obstacle to achieve trustful hand-made calculations and therefore a numerical model was created using the software COMSOL Multiphysics©. …
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