Download or read book An Experimental Investigation of Fuel Spray Vapor Phase Characterization written by James Arthur Drallmeier and published by . This book was released on 1989 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study of an infrared laser extinction technique for measuring fuel vapor flux in evaporating liquid fuel sprays was conducted. The infrared laser extinction technique consists of three separate measurements: a visible light angular scattering measurement, a visible light line-of-sight extinction measurement and an infrared line-of-sight extinction measurement. Using this technique, vapor flux along with other spray parameters such as mean drop size and size distribution were measured for a pressure atomized, isooctane fuel spray. Line-of-sight infrared extinction measurements were deconvoluted to obtain radial variations of vapor concentration. Peak vapor concentrations were measured at the spray center due to air entrainment effects. Based on the radial mass fraction and measured gas phase velocity profiles, the fuel vapor mass flux was calculated; most of the vapor flux was contained in the center of the spray at all axial locations. The fuel vapor mass flux was integrated over the spray area at each axial location to obtain fuel vapor mass flow rates. Comparisons were made between the infrared laser extinction technique and a Phase/Doppler Particle Analyzer (P/DPA) in terms of several spray parameters including drop size, size distribution and, in particular, vapor flux. Size comparisons were conducted on a spatially resolved and line-of-sight basis. While the spatially resolved comparisons indicated similar trends, the angular scattering measurements consistently predicted Sauter mean diameter results $sim$10 $mu$m larger than those obtained from the P/DPA. Comparisons of measured total fuel vapor flow yielded differences of 7 to 40% between the P/DPA and infrared extinction technique. A detailed error analysis was performed to determine the error sensitivities of the vapor concentration to the measured parameters as a function of spray radius. The vapor concentration was relatively insensitive to the measured drop size distribution due to the fact that the vapor absorption was the most dominant mode of extinction. The vapor concentration was most sensitive to the measurement of the infrared extinction ratio. An upper limit for the overall error in the vapor concentration measurement was estimated at 15% over the spray radius.
Download or read book Experimental Investigation of Effects of Fuel Injection Parameters and Chamber Wall Confinement on Spray Characteristics in Constant Volume Bomb written by S-x Shi and published by . This book was released on 1991 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigation of Near nozzle Characteristics of Gasoline Sprays from Pressure swirl Atomisers written by and published by . This book was released on 2005 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Explosion Characteristics of Multiphase Fuel Mixtures with Air written by Emmanuel Kwasi Addai and published by Western Engineering, Inc.. This book was released on 2016-10-10 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explosion hazards involving mixtures of different states of aggregation continue to occur in facilities where dusts, gases or solvents are handled or processed. In order to prevent or mitigate the risk associated with these mixtures, more knowledge of the explosion behavior of hybrid mixtures is required. The aim of this study is to undertake an extensive investigation on the explosion phenomenon of hybrid mixtures to obtain insight into the driving mechanisms and the explosion features affecting the course of hybrid mixture explosions. This was accomplished by performing an extensive experimental and theoretical investigation on the various explosion parameters such as: minimum ignition temperature, minimum ignition energy, limiting oxygen concentration, lower explosion limits and explosion severity. Mixtures of twenty combustible dusts ranging from food substances, metals, plastics, natural products, fuels and artificial materials; three gases; and six solvents were used to carry out this study. Three different standard equipments: the 20-liter sphere (for testing lower explosion limits, limiting oxygen concentration and explosion severity), the modified Hartmann apparatus (for testing minimum ignition energy) and the modified Godbert–Greenwald (GG) furnace (for testing minimum ignition temperature) were used. The test protocols were in accordance with the European standard procedures for dust testing for each parameter. However, modifications were made on each equipment in order to test the explosion properties of gases, solvents, and hybrid mixtures. The experimental results demonstrated a significant decrease of the minimum ignition temperature, minimum ignition energy and limiting oxygen concentration of gas or solvent and increase in the likelihood of explosion when a small amount of dust, which was either below the minimum explosion concentration or not ignitable by itself, was mixed with gas or solvent and vice versa. For example, methane with minimum ignition temperature of 600 °C decreased to 530 °C when 30 g/m3 of toner dust, which is 50 % below its minimum explosible concentration was, added. A similar explosion behavior was observed for minimum ignition energy and limiting oxygen concentration. Furthermore, it was generally observed that the addition of a non-explosible concentration of flammable gas or spray to a dust-air mixture increases the maximum explosion pressure to some extent and significantly increases the maximum rate of pressure rise of the dust mixture, even though the added concentrations of gases or vapor are below its lower explosion limit. Finally, it could be said that, one cannot rely on the explosion properties of a single substance to ensure full protection of an equipment or a process if substances with different states of aggregate are present.
Download or read book Recent Advances in Spray Combustion written by Kenneth K. Kuo and published by AIAA. This book was released on 1996 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liquid Atomization written by L.P. Bayvel and published by Routledge. This book was released on 2019-01-22 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the basics of liquid atomization, this book familiarizes readers with the physical processes of liquid atomization, the main types of atomizers and their design, measurements of spray characteristics, experimental investigations of atomizers, and application of atomizers. It demonstrates how to calculate and design atomizers and how to mea
Download or read book Experimental Investigation of Ignition Combustion and Stability Characteristics of a Coaxial Sudden Expansion Burner written by Stephen N. Schmotolocha and published by . This book was released on 1974 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes studies performed on mixing, ignition, flame stability limits and combustion of liquid injected hydrocarbon fuels in a coaxial dump burner. The effects of flow conditions, injection distance, inlet geometry, fuel type and piloting were investigated. It was found that ignition limits differ from lean blowout limits, and that stable flames could be sustained over much wider range than the homogeneous gaseous mixtures. Results also indicate that ignition and flame stability mechanisms are controlled by the vapor phase fuel concentration level in the addy zone similar to spray mixtures, and not the global fuel/air ratio as in the case of homogeneous gaseous mixtures. Fuel injection distance has a profound effect on ignition but not on blowout limits. The observations indicate that increasing inlet velocity, air temperature or relatively low energy piloting improves, even significantly, both the recirculation zone and the overall combustion performance. RJ-5, although more difficult to ignite, exhibits higher heat release rates than JP-4. (Modified author abstract).
Download or read book AIAA 28th Aerospace Sciences Meeting written by and published by . This book was released on 1990 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Liquid Fuel Evaporation of a Lifted Methanol Spray Flame in a Vitiated Coflow Burner written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation of lifted spray flames in a coflow of hot, vitiated gases is presented. The vitiated coflow burner is a spray flame that issues into a coaxial flow of hot combustion products from a lean, premixed H2/Air flame. The spray flame in a vitiated coflow emulates the combustion that occurs in many advanced combustors without the detailed fluid mechanics. Two commercially available laser diagnostic systems are used to characterize the spray flame and to demonstrate the vitiated coflow burner's amenability to optical investigation. The Ensemble Particle Concentration and Size (EPCS) system is used to measure the path-average droplet size distribution and liquid volume fraction at several axial locations while an extractive probe instrument named the Real-time Fuel-air Analyzer (RFA) is used to measure the air to fuel ratio downstream of the spray nozzle with high temporal and spatial resolution. The effect of coflow conditions (stoichiometry) and dilution of the fuel with water was studied with the EPCS optical system. As expected, results show that water retards the evaporation and combustion of fuels. Measurements obtained by the RFA extractive probe show that while the Delavan manufactured nozzle does distribute the fuel over the manufacturer specified spray angle, it unfortunately does not distribute the fuel uniformly, providing conditions that may result in the production of unwanted NOx. Despite some limitations due to the inherent nature of the experimental techniques, the two diagnostics can be readily applied to spray flames in the vitiated coflow environment. Cabra, Ricardo and Dibble, Robert W. and Chen, Jyh-Yuan Glenn Research Center NASA/CR-2002-212083, NAS 1.26:212083, E-13736
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1995 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AN EXPERIMENTAL AND COMPUTATIONAL STUDY OF FUEL SPRAY INTERACTION written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : 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 interaction outcomes, in particular focusing on the splashing criteria, were inspected and post-impingement characterizations including spreading factor, height ratio, contact line velocity, and dynamic contact angle was further analyzed based on the experimental data. The non-evaporation volume of fluid (VOF) model based on Eulerian approach was used to characterize single droplet impinging on the wall and provide a better understanding of the dynamic impact process. In addition, the study of droplet-to-droplet collision and multi-droplet impingement on a solid surface are performed, which is essential to aid in the spray-wall impingement investigation. As well, due to the evaporation drawing more attention during the engine combustion process, an evaporation VOF sub-model was developed and applied to multi-droplet impingement on a hot surface to qualitatively and quantitatively analyze the vaporizing process as droplets impacting onto the hot surface. After that, the non-vaporizing and vaporizing spray characteristics of spray-wall impingement at various operating conditions relevant to diesel engines were undertaken, with spray characterized using schlieren and Mie scattering diagnostics, as well as Refractive Index Matching (RIM) technique. Free and impinged spray structures and deposited wall-film formation and evaporation were qualitatively analyzed, spray properties and wall-film properties were quantified, and surface temperature and heat flux were measured. An Eulerian-Lagrangian modeling approach was employed to characterize the spray-wall interactions by means of a Reynolds-Averaged Navier-Stokes (RANS) formulation. The local spray characteristics in the vicinity of the wall and the local spray morphology near the impingement location were studied. Furthermore, multiple spray-to-spray collision derived from droplet-to-droplet collision, considering as one of the advanced injection strategies to enhance the engine performance, was studied at various gasoline engine conditions to explore the effect of colliding spray on spray related phenomena like atomization, vaporization, and mixing. Spray characteristics were obtained by the schlieren diagnostics and the experimental validated Computational Fluid Dynamic (CFD) simulations were based on Eulerian-Lagrangian approach to understand the mechanism behind the collisions of sprays and characterize the different types of multiple spray-to-spray collision. In summary, on the strength of the study of droplet-wall impingement and droplet-to-droplet collision at non-evaporation and evaporation states, the main objective of this dissertation is to enhance the understanding of spray-wall impingement and multiple spray-to-spray collision under diesel or gasoline engine conditions from both experiments and CFD simulations, therefore providing feedbacks to the ultimate task in future development and application of a more reliable and effective fuel injection system.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1998 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat and Mass Transfer written by T. Nejat Veziroğlu and published by . This book was released on 1994 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 912 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 93 2028 93 2069 written by and published by . This book was released on 1992 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt:
