Download or read book Effects of Fuel Injection on Mixing and Upstream Interactions in Supersonic Flow written by Qiuya Tu and published by . This book was released on 2013 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simulation for shock wave/ boundary-layer interaction was conducted in Fluent for case of M=1.9 at 60% blockage by using k- RNG model with two different near wall treatments. In both cases, the shock ran out of isolator before the computation converged, this is different from experimental results. Proper actual wall friction force may have a very important effect on the computation, which needs to be evaluated.
Download or read book Effect of Flow Distortion on Fuel Mixing and Combustion in an Upstream fueled Cavity Flameholder for a Supersonic Combustor written by Steven J. Etheridge and published by . This book was released on 2012 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: Typical studies of scramjet combustion employ as uniform a flowpath as possible. These studies are important to isolate the effects of a given combustor configuration. However, such studies tend to ignore the effects of a shock train created by the vehicle installation and that this shock train changes over the flight envelope. Consequently, the performance of a given configuration is measured without considering the considerable effects of this shock train or how it changes with different flight conditions. This thesis includes experimental and computational studies of the effects of an incident shockwave on the flowfield, fuel distribution and combustion within a cavity flameholder with upstream fuel injection. The effect of the shockwave location (on the upstream fuel jet or over the cavity) and shock angle are controlled by adjusting a shock generator mounted in the tunnel test section. The effect of fuel injection momentum ratio is also examined. Shadowgraphy is used to characterize the flowfield while planar laser induced fluorescence of the NO and OH molecules are used to measure the fuel mixing and combustion, respectively. These experimental data are compared with CFD solutions of the Reynolds Averaged Navier-Stokes equations provided in previous CFD work. The effect of the shock on the cavity shear layer is found to control the fuel distribution within the cavity. The shock on jet impingement forces the shear layer deep within the cavity and results in higher concentrations near the cavity centerline, but low mixing uniformity. The shock on cavity case causes the shear layer to separate upstream of the cavity, mixing uniformity is enhanced by the increased breakup of the fuel plume. Combustion is stronger and more uniform in the shock on cavity case, while it is limited to the edges of the cavity with shock impingement on the jet. The greater mixing afforded in the shock on cavity case reduces the fuel concentration near the centerline and permits stronger burning in the center of the cavity. Small changes in the fuel injection momentum ratio (doubling) do not strongly affect the pattern of fuel distribution in any case. Combustion in the shock on cavity case is reduced by increasing fuel injection momentum because the fuel concentration at the centerline is too high. Small increases in the shock angle did not strongly affect the results.
Download or read book Scramjets written by Mostafa Barzegar Gerdroodbary and published by Butterworth-Heinemann. This book was released on 2020-07-21 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scramjet engines are a type of jet engine and rely on the combustion of fuel and an oxidizer to produce thrust. While scramjets are conceptually simple, actual implementation is limited by extreme technical challenges. Hypersonic flight within the atmosphere generates immense drag, and temperatures found on the aircraft and within the engine can be much greater than that of the surrounding air. Maintaining combustion in the supersonic flow presents additional challenges, as the fuel must be injected, mixed, ignited, and burned within milliseconds. Fuel mixing, along with the configuration and positioning of the injectors and the boundary conditions, play a key role in combustion efficiency. Scramjets: Fuel Mixing and Injection Systems discusses how fuel mixing efficiency and the advantage of injection systems can enhance the performance of the scramjets. The book begins with the introduction of the supersonic combustion chamber and explains the main parameters on the mixing rate. The configuration of scramjets is then introduced with special emphasis on the main effective parameters on the mixing of fuel inside the scramjets. In addition, basic concepts and principles on the mixing rate and fuel distribution within scramjets are presented. Main effective parameters such as range of fuel concentration for the efficient combustion, pressure of fuel jet and various arrangement of jet injections are also explained. This book is for aeronautical and mechanical engineers as well as those working in supersonic combustion who need to know the effects of compressibility on combustion, of shocks on mixing and on chemical reactions, and vorticity on the flame anchoring. - Explains the main applicable approaches for enhancement of supersonic combustion engines and the new techniques of fuel injection - Shows how the interaction of main air stream with fuel injections can develop the mixing inside the scramjets - Presents results of numerical simulations and how they can be used for the development of the combustion engines
Download or read book Fuel vortex Interactions for Enhanced Mixing in Supersonic Flow written by Raymond Preston Fuller and published by . This book was released on 1996 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scramjet Combustion written by Gautam Choubey and published by Butterworth-Heinemann. This book was released on 2022-07-08 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scramjet Combustion explores the development of a high-speed scramjet engine operating in the supersonic/hypersonic range for various air and space transport applications. The book explains the basic structure, components, working cycle, and the relevant governing equations in a clear manner that speaks to both advanced and more novice audiences. Particular attention is paid to efficient air–fuel combustion, looking at both the underlying fundamentals of combustion as well strategies for obtaining optimum combustion efficiency. Methods for reaching the chemically correct air–fuel ratio, subsequent flame, and combustion stabilization as air enters at supersonic speed are also outlined. Further, it includes the continuous on-going efforts, innovations, and advances with respect to the design modification of scramjet combustors, as well as different strategies of fuel injections for obtaining augmented performance while highlighting the current and future challenges. - Outlines the fundamentals of scramjet engines including their basic structure and components, working cycle, governing equations, and combustion fundamentals affecting the combustion and mixing processes - Presents new design modifications of scramjet combustors and different fuel injection strategies including combined fuel injection approaches - Discusses core topics such as chemical kinetics in supersonic flow, fuel–air mixing methods, strategies for combating combustion difficulties, and subsequent flame and combustion stabilization that can be applied to scramjets - Describes the pedagogy for computational approaches in simulating supersonic flows
Download or read book The Scramjet Engine written by Corin Segal and published by Cambridge University Press. This book was released on 2009-06-22 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: The renewed interest in high-speed propulsion has led to increased activity in the development of the supersonic combustion ramjet engine for hypersonic flight applications. In the hypersonic regime the scramjet engine's specific thrust exceeds that of other propulsion systems. This book, written by a leading researcher, describes the processes and characteristics of the scramjet engine in a unified manner, reviewing both theoretical and experimental research. The focus is on the phenomena that dictate the thermo-aerodynamic processes encountered in the scramjet engine, including component analyses and flowpath considerations; fundamental theoretical topics related to internal flow with chemical reactions and non-equilibrium effects, high-temperature gas dynamics, and hypersonic effects are included. Cycle and component analyses are further described, followed by flowpath examination. Finally, the book reviews experimental and theoretical capabilities and describes ground testing facilities and computational fluid dynamics facilities developed for the study of time-accurate, high-temperature aerodynamics.
Download or read book Interaction Between Step Fuel Injectors on Opposite Walls in a Supersonic Combustor Model written by Charles R. McClinton and published by . This book was released on 1978 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scramjet Propulsion written by E. T. Curran and published by AIAA. This book was released on 2001 with total page 1354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Initial Flow Nonuniformity on Second stage Fuel Injection and Combustion in a Supersonic Duct written by William Roger Russin and published by . This book was released on 1975 with total page 60 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 2023-01-10 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 Investigation of Supersonic Mixing Control Using Cavities written by R. Burnes and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study on the Turbulence Characteristics and Mixing Performance of Streamwise Vortex Interactions in Supersonic Flow written by Cody R. Ground and published by . This book was released on 2019 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The scramjet engine offers the unique capability to enable sustained air breathing flight at hypersonic speeds. However, in order to reach its full application potential, further technological maturation of several system level components is necessary. One such component is the fuel injection system. The flow conditions characteristic of the scramjet combustor are such that the rate-limiting step in the fuel injection/mixing/combustion process is the mixing of the fuel and air. For this reason, the fuel injection system must be designed with the goal of enhancing the rate of fuel/air mixing. One method that has shown potential to enhance fuel/air mixing in supersonic flows is the introduction of streamwise vorticity into the mixing field, yet there are many fundamental aspects of this concept that remain relatively uninvestigated. One such aspect is the capability to use specific streamwise vortex interaction modes to synergistically increase mixing in the flow. However, in order to target specific vortex interactions which act to enhance mixing in the design stage of a fuel injection system a better foundational knowledge of streamwise vortex interactions in supersonic flows must be obtained. To this end, this dissertation presents a fundamental experimental investigation into two elemental modes of vortex interaction, the merging and non-merging of a pair of co-rotating streamwise vortices. The experimental investigations were all conducted at the University of Texas at Arlington Aerodynamics Research Center in the blow-down Supersonic Wind Tunnel Facility which delivered a Mach 2.5 free stream flow for all of the experiments detailed herein. To create the targeted vortex interaction modes specific configurations of vortex generating ramps were affixed to the trailing edge of a strut injector. The experiments detailed in this dissertation accomplish two tasks in the continuation of the group's previous research on the merging and non-merging modes of streamwise vortex interaction. The first task that will be presented is the analysis of the fluctuating velocity flow fields of the two studied vortex interactions with the proper orthogonal decomposition (POD) technique. This analysis is approached in order to quantify the organization and relative turbulent kinetic energy content of the various scales of turbulent coherent structures of the flow. The results of the POD analysis revealed that the vortex merging process reorients and redistributes the turbulent kinetic energy content towards the larger coherent structures captured in the low-order eigenmodes of the POD. The second task presented in this dissertation is the non-intrusive laser-based quantification of the mixing performance of the two vortex interactions using the filtered Rayleigh scattering (FRS) technique. Applying the FRS technique to retrieve mixture composition measurements in highly complex flows such as the flows studied here is a nontrivial task. For this reason, experiments were initially performed in a canonical two-dimensional planar shear layer to compare the relative accuracy of filtered Rayleigh scattering measurements with intrusive gas-sampling based mixture composition measurements. With this comparison yielding good levels of agreement between the two techniques, the FRS technique was able to be confidently applied in the vortical flows of primary interest. The main conclusion obtained from the FRS experiments was the finding that the non-merging vortex interaction more rapidly mixes the fuel and air due to its increased rate of entrainment with respect to the merging vortex interaction. Taken together, the results of the two analyses presented in this dissertation highlight the necessity of considering streamwise vortex interactions in the design stage of scramjet fuel injection systems since all differences in the flowfields of the two studied cases arise solely due to the different vortex interaction modes generated. Most importantly, this work has laid the foundation for future fundamental vortex dynamics studies which seek to optimize these (and other) modes of interaction by using the analysis and measurement techniques described herein.
Download or read book Applied Gas Dynamics written by Ethirajan Rathakrishnan and published by John Wiley & Sons. This book was released on 2019-02-25 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: A revised edition to applied gas dynamics with exclusive coverage on jets and additional sets of problems and examples The revised and updated second edition of Applied Gas Dynamics offers an authoritative guide to the science of gas dynamics. Written by a noted expert on the topic, the text contains a comprehensive review of the topic; from a definition of the subject, to the three essential processes of this science: the isentropic process, shock and expansion process, and Fanno and Rayleigh flows. In this revised edition, there are additional worked examples that highlight many concepts, including moving shocks, and a section on critical Mach number is included that helps to illuminate the concept. The second edition also contains new exercise problems with the answers added. In addition, the information on ram jets is expanded with helpful worked examples. It explores the entire spectrum of the ram jet theory and includes a set of exercise problems to aid in the understanding of the theory presented. This important text: Includes a wealth of new solved examples that describe the features involved in the design of gas dynamic devices Contains a chapter on jets; this is the first textbook material available on high-speed jets Offers comprehensive and simultaneous coverage of both the theory and application Includes additional information designed to help with an understanding of the material covered Written for graduate students and advanced undergraduates in aerospace engineering and mechanical engineering, Applied Gas Dynamics, Second Edition expands on the original edition to include not only the basic information on the science of gas dynamics but also contains information on high-speed jets.
Download or read book IUTAM Symposium on Combustion in Supersonic Flows written by M. Champion and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the IUTAM Symposium held in Poitiers, France, 2-6 October 1995
Download or read book Experimental Investigation of Transverse Supersonic Gaseous Injection Enhancement Into Supersonic Flow written by Mark P. Wilson and published by . This book was released on 1996-12-01 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: In pursuit of more efficient and effective fuel-air mixing for a SCRAMJET combustor, this study was conducted to investigate relative near field enhancements of penetration and mixing of a discrete low-angled (25 deg) injected air jet into a supersonic (M=2.9) cross flow. The enhancements were achieved by injecting the transverse air jet parallel to the compression face of eight different ramp geometries. The jet-ramp interactions created collinear shock structures, baroclinic torque vorticity enhancement, ramp spillage enhanced vorticity, magnus effect penetration enhancement, and increased total pressure loss. Shadowgraph photography was used to identify the shock structures and interactions in the flow field. Measurements of mean flow properties were used to establish the jet plume size, jet plume penetration and to quantify the total pressure loss created by the ramps. Rayleigh-Mie scattering images were used for both qualitative flow field assessments and quantitative analysis of the plume trajectory and mixing rate. Results indicate that up to a 20% increase in penetration height and plume expansion can be achieved by injection over a ramp compared to simple transverse injection. This increase in penetration and mixing incurs up to a 15% loss in total pressure. The most critical geometric aspects that affect the flow are the ramp compression face shape and frontal aspect, and the location and strength of ramp generated expansion.
Download or read book Interaction Between Step Fuel Injectors on Opposite Walls in a Supersonic Combustor Model written by Charles R. McClinton and published by . This book was released on 1978 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interaction Between Mixing and Combustion of Slot injected Fuel in a Supersonic Combustor written by Sadatake Tomioka and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
