Download or read book Effect of Jet Injection Angle and Number of Jets on Mixing and Emissions from a Reacting Crossflow at Atmospheric Pressure written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mixing of air jets into hot, fuel-rich products of a gas turbine primary zone is an important step in staged combustion. Often referred to as "quick quench," the mixing occurs with chemical conversion and substantial heat release. An experiment has been designed to simulate and study this process, and the effect of varying the entry angle (0 deg, 22.5 deg and 45 deg from normal) and number of the air jets (7, 9, and 11) into the main flow, while holding the jet-to-crossflow mass-low ratio, MR, and momentum-flux ratio, J, constant (MR = 2.5;J = 25). The geometry is a crossflow confined in a cylindrical duct with side-wall injection of jets issuing from orifices equally spaced around the perimeter. A specially designed reactor, operating on propane, presents a uniform mixture to a module containing air jet injection tubes that can be changed to vary orifice geometry. Species concentrations of O2, CO, CO2, NO(x) and HC were obtained one duct diameter upstream (in the rich zone), and primarily one duct radius downstream. From this information, penetration of the jet, the spatial extent of chemical reaction, mixing, and the optimum jet injection angle and number of jets can be deduced. St.John, D. and Samuelsen, G. S. Glenn Research Center NASA/CR-2000-209949, E-12202, NAS 1.26:209949
Download or read book Effect of Jet Injection Angle and Number of Jets on Mixing and Emissions From a Reacting Crossflow at Atmospheric Pressure written by D. St John and published by . This book was released on 2000 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Jet Mixing on the Combustion Efficiency of a Hot Fuel rich Cross flow written by Mohamed Boutazakhti and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many combustion systems inject air into a hot fuel-rich cross-flow to minimize carbon monoxide and unburned hydrocarbon emissions. Examples include staged air injection in fluidized bed combustors, gas turbine engines, and electric arc furnace exhaust afterburners. Low CO and unburnt hydrocarbon emissions are important design objectives. Efforts in modeling combustion have failed in accurately predicting the levels of these emissions. The main aim of this study is to improve our understanding of the relationship between mixing, chemical kinetics, and combustion efficiency for air jets in a hot reacting cross-flow. Carbon monoxide and hydrogen concentration measurements have been made for six different round jet configurations issuing air into a hot reacting cross-flow. The study of the performance of four different 9 round jets modules having different jet diameters indicated that the overall equivalence ratio has a significant effect on the maximum combustion efficiency. An equivalence ratio of approximately 0.8 leads to the best combustion efficiency for all of the 9 round jet modules. This result is similar to what is observed in premixed combustion. The predominance of the effect of the equivalence ratio suggests that some premixing between the jets and the cross-flow takes place prior to combustion. The rest of the experiments were run such that the optimum mixing (according to cold flow theory) occurs at [Phi] = 0.8. The experiments also showed that, although the equivalence ratio does not control the location of the optimum point, it does affect the level of emissions. In fact, at constant equivalence ratio, low momentum flux ratios yield higher emissions. The number of jets affects the level of emissions. Larger number of jets provided better combustion efficiency. The unmixedness was measured for the 18 round jets module. This measurement showed the momentum flux ratio is a driving factor affecting mixing. The comparison of the combustion efficiency of H2 and CO suggest that the reaction rate affect the level of combustion efficiency without affecting the location of the optimum.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Mixing of Pure Air Jets with a Reacting Fuel Rich Crossflow written by and published by . This book was released on 1997 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scramjet Propulsion written by Dora Musielak and published by John Wiley & Sons. This book was released on 2022-11-16 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scramjet Propulsion Explore the cutting edge of HAP technologies with this comprehensive resource from an international leader in her field Scramjet Propulsion: A Practical Introduction delivers a comprehensive treatment of hypersonic air breathing propulsion and its applications. The book covers the most up-to-date hypersonic technologies, like endothermic fuels, fuel injection and flameholding systems, high temperature materials, and TPS, and offers technological overviews of hypersonic flight platforms like the X-43A, X-51A, and HiFIRE. It is organized around easy-to-understand explanations of technical challenges and provides extensive references for the information contained within. The highly accomplished author provides readers with a fulsome description of the theoretical underpinnings of hypersonic technologies, as well as critical design and technology issues affecting hypersonic air breathing propulsion technologies. The book’s combination of introductory theory and advanced instruction about individual hypersonic engine components is ideal for students and practitioners in fields as diverse as hypersonic vehicle and propulsion development for missile defense technologies, launch aerospaceplanes, and civilian transports. Over 250 illustrations and tables round out the material. Readers will also learn from: A thorough introduction to hypersonic flight, hypersonic vehicle concepts, and a review of fundamental principles in hypersonic air breathing propulsion Explorations of the aerothermodynamics of scramjet engines and the design of scramjet components, as well as hypersonic air breathing propulsion combustors and fuels Analyses of dual-mode combustion phenomena, materials structures, and thermal management in hypersonic vehicles, and combined cycle propulsion An examination of CFD analysis, ground and flight testing, and simulation Perfect for researchers and graduate students in aerospace engineering, Scramjet Propulsion: A Practical Introduction is also an indispensable addition to the libraries of engineers working on hypersonic vehicle development seeking a state-of-the-art resource in one of the most potentially disruptive areas of aerospace research today.
Download or read book NASA SP written by and published by . This book was released on 1993 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flow Field and Mixing Characteristics of Multiple Reacting Jets in Vitiated Crossflow written by George M. Lapaan and published by . This book was released on 2014 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mixing of Jet in Crossflow written by Sameer Ghalsasi and published by . This book was released on 2003 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Jet Mixing and Emission Characteristics of Transverse Jets in Annular and Cylindrical Confined Crossflow written by D. B. Bain and published by . This book was released on 1995 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimization of Jet Mixing Into a Rich Reacting Crossflow written by M. Y. Leong and published by . This book was released on 1997 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2668 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mixing of pure air jets with a reacting fuel rich crossflow written by M. Y. Leong and published by . This book was released on 1997 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Investigation of Jets in a Reacting Crossflow written by Hanan Urson and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mixing of air jets into hot, fuel-rich mixture is an integral part of many staged combustion applications. This study concentrates on the exhaust system of an electric arc steelmelting furnace where high concentrations of carbon monoxide (CO) and hydrogen (H2) are present. A three dimensional numerical code featuring two combustion models has been used to predict those emissions for various jet to cross-stream mass flow ratios and a comparison with experimental CO was done. The results showed that both models were unable to predict CO and H2 emissions for the conditions investigated. Thorough examination of the non-premixed flamelet revealed that the turbulent tune scale was much faster than the chemical time scale, thus, collapsing one of the requirements of this model. With the eddy dissipation model, the CO and H2 concentrations were severely underpredicted and convergence problem occurred when dissimilar chemical kinetic rates for CO and H 2 were incorporated.
Download or read book Mixing of Multiple Jets With a Confined Subsonic Crossflow in a Cylindrical Duct written by James D. Holdeman and published by . This book was released on 1996 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine and Aeroengine Congress & Exhibition, Birmingham, UK, Jun 10-13, 1996.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1032 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIAA Aerospace Sciences Meeting and Exhibit 42nd written by and published by . This book was released on 2004 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt:
