Topic
Chamber pressure
About: Chamber pressure is a research topic. Over the lifetime, 2988 publications have been published within this topic receiving 30725 citations.
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TL;DR: In this article, high pressure diesel fuel injection into the combustion chamber by performing computational simulations using the Euler-Eulerian multiphase approach was investigated, and the results showed good agreement when compared to the measured data, and yielded the correct trends for both the liquid and vapour penetrations under different operating conditions.
49 citations
TL;DR: In this article, a simple model is presented which relates the film composition x to the measured beam current density JF, the vapor impingement rate Q, and the chamber pressure p. The model is examined as a potential source of both systematic and random deviations of the data from the model.
Abstract: An ion‐beam‐assisted‐deposition (IBAD) system is under development to fabricate Si1−x Nx films for optical devices. Reproducible film composition requires characterization of the relationship between the incorporated nitrogen atom fraction x and the real time experimental measurable quantities. In this paper a simple model is presented which relates the film composition x to the measured beam current density JF , the vapor impingement rate Q, and the chamber pressure p. Effects included in the model are reflection of energetic particles, sputtering from the film surface, and charge exchange neutralization of the ions. Each term in the model is examined as a potential source of both systematic and random deviations of the data from the model. Data on film composition as a function of the nitrogen ion current to deposition rate ratio are presented for several sets of ion source voltages and chamber pressures. It is shown that by modifying the deposition system so as to minimize the identified sources of err...
49 citations
TL;DR: In this article, the activation energy for surface diffusion of gold nanoparticles on SiO2 nanowires was determined to be 10.4 kJ/mol using transmission electron microscopy.
Abstract: Production of gold nanoparticles with the specific goal of particle size control has been investigated by systematic variation of chamber pressure and substrate temperature. Gold nanoparticles have been synthesized on SiO2 nanowires by plasma-enhanced chemical vapor deposition. Determination of particle size and particle size distribution was done using transmission electron microscopy. Average nanoparticle diameters were between 4 and 12 nm, with particle size increasing as substrate temperature increased from 573 to 873 K. A bimodal size distribution was observed at temperatures ≥723 K indicating Ostwald ripening dominated by surface diffusion. The activation energy for surface diffusion of gold on SiO2 was determined to be 10.4 kJ/mol. Particle sizes were found to go through a maximum with increases in chamber pressure. Competition between diffusion within the vapor and dissociation of the precursor caused the pressure effect.
49 citations
Patent•
13 May 1991
TL;DR: A wheel mounted intermediate between the gas pressurizing source and the tire gas valve inlet is described in this article, where a spring loaded valve disk is used to control relief or venting orifices.
Abstract: A tire fill valve (2) having pressure relief and tire fill fluid gas flow limiting characteristics for use in filling tires to a predetermined pressure from a large flow capacity gas source delivering fill gas at a substantially greater pressure. Gases utilized typically are air or nitrogen. The valve (2) of the invention is wheel mounted intermediate the gas pressurizing source and the tire gas valve inlet (1). Tire fill gas from a high pressure high capacity source passes through a flow limiting orifice (26) having a positive closure or shutoff member (28) and passes through a pressure sensitive chamber (42) as it enters the tire. Chamber pressure is sensed by a spring loaded valve disk (46) controlling relief or venting orifices. When fill pressure in the pressure sensitive chamber (42) exceeds a predetermined value established by the valve disk area and valve disk springs (44), the disk (46) lifts allowing the venting of the fill gas. Overpressurization of the pressure sensitive chamber (42) and tire with the disk (46) in its relief position is prevented by limited flow and/or positive flow shutoff through the chamber entrance or flow limiting orifice (26).
49 citations
TL;DR: In this paper, a constant volume chamber system was used to characterize the ignition and combustion of a diesel fuel, where fuel is injected in the chamber through a standard diesel common rail injection system and initial chamber conditions were varied: fuel injection pressure (600 to 1000 bar), injection duration (500 to 3000 μs), initial temperature (808 to 923 K), initial pressures (6 to 21 bar), and oxygen mole fractions (15 to 30% diluted in nitrogen).
Abstract: A constant volume chamber system was used to characterize the ignition and combustion of a diesel fuel. Fuel is injected in the chamber through a standard diesel common rail injection system. Injection parameters and initial chamber conditions were varied: fuel injection pressure (600 to 1000 bar), injection duration (500 to 3000 μs), initial temperature (808 to 923 K), initial pressures (6 to 21 bar), and oxygen mole fractions (15 to 30% diluted in nitrogen). Multiple measurements confirmed the repeatability of the measurements. Most of the experiments showed a two-stage combustion process, especially at low chamber pressure and highly premixed conditions. This is characteristic of large paraffinic hydrocarbons such as those composing around two-thirds of commercial diesel fuels. Combustion pressure data from diesel fuel have shown a moderate effect of injection pressure and injection duration on the ignition delays, especially when compared to the effect of other operation parameters. A strong effect of...
49 citations