Download or read book Support for Graduate Research in Supersonic Reacting Flows written by Mark Godfrey Mungal and published by . This book was released on 1998 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work was aimed at obtaining a more fundamental understanding of mixing and combustion in supersonic flows. Advanced laser based techniques for measurements in an existing supersonic shear layer facility were primarily used. The main scientific question addressed was a comparison of the similarities and differences between mixing and reaction when compressibility plays a significant role. To this end, Particle Image Velocimetry (PIV) was used to obtain detailed, whole field velocity measurements under a range of compressibility conditions. These measurements are complementary to earlier measurements of scalar concentrations in similar flows. New observations concerning the nature of the instantaneous velocity and vorticity fields were made as a function of compressibility. In addition, Planar Laser Mie Scattering is used to obtain structure velocity measurements for comparison with the actual fluid velocities.
Download or read book Research on Supersonic Reacting Flows written by and published by . This book was released on 1995 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental and computational investigation of supersonic reacting flows, with the objective of gaining a fundamental understanding of the flow physics and chemistry interactions, is in progress. During the past year, experiments were conducted in a supersonic shear flow facility to visualize the instantaneous, three-dimensional structure of the compressible mixing layer and to measure the mixing efficiency. The mixing efficiency was measured by applying a new planar laser-induced fluorescence (PLIF) technique, termed "cold chemistry." The PLIF techniques, developed previously in our laboratory, were refined to allow measurements of temperature, velocity and multiple species in transient high-speed flows. Current codes for direct numerical simulation of time-developing, three-dimensional, reacting, compressible mixing layers were adapted for a new generation of supercomputers. Previously-developed stability analyses were extended to the range of conditions being investigated in the supersonic reacting flow experiments. (AN).
Download or read book Final Technical Report on Research on Supersonic Reacting Flows written by and published by . This book was released on 1997 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental and computational investigation of supersonic combustion flows was carried out. The principal objective of the research was to gain a more fundamental understanding of mixing and chemical reaction in supersonic flows. The research effort comprised three interrelated elements: (1) stability analyses and numerical simulations of compressible reacting flows; (2) development of laser induced fluorescence techniques for time resolved multidimensional imaging of species concentration, temperature, velocity and pressure; and (3) an experimental study of mixing and combustion in a supersonic plane mixing layer with the additional development of simple mixing enhancements. The specific objectives and results of the research of each of these program elements have been summarized in this report. New results include: (1) a detailed stability map for reacting, compressible shear layers; (2) new PLIF techniques for transient facilities; (3) new measurements of mixing efficiency in compressible flows; and (4) demonstration of simple mixing enhancement techniques with low pressure drop.
Download or read book Turbulent Reacting Flows and Supersonic Combustion written by C. T. Bowman and published by . This book was released on 1990 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental and computational investigation of supersonic combustion flows was carried out. The principal objective of the research was to gain a more fundamental understanding of mixing and chemical reaction in supersonic flows. The research effort comprised three inter-related elements: (1) an experimental study of mixing and combustion in a supersonic plane mixing layer; (2) development of laser-induced fluorescence techniques for time-resolved two-dimensional imaging of species concentration, temperature and velocity; and (3) numerical simulations of compressible reacting flows. The specific objectives and the results of the research is summarized. Keywords: Turbulent reacting flow; Supersonic combustion. (jhd).
Download or read book A Two dimensional Numerical Simulation of a Supersonic Chemically Reacting Mixing Layer written by John Philip Drummond and published by . This book was released on 1988 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Two Dimensional Numerical Simulation of a Supersonic Chemically Reacting Mixing Layer written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research has been undertaken to achieve an improved understanding of physical phenomena present when a supersonic flow undergoes chemical reaction. A detailed understanding of supersonic reacting flows is necessary to successfully develop advanced propulsion systems now planned for use late in this century and beyond. In order to explore such flows, a study was begun to create appropriate physical models for describing supersonic combustion, and to develop accurate and efficient numerical techniques for solving the governing equations that result from these models. From this work, two computer programs were written to study reacting flows. Both programs were constructed to consider the multicomponent diffusion and convection of important chemical species, the finite rate reaction of these species, and the resulting interaction of the fluid mechanics and the chemistry. The first program employed a finite difference scheme for integrating the governing equations, whereas the second used a hybrid Chebyshev pseudospectral technique for improved accuracy. Drummond, J. Philip Langley Research Center BOUNDARY LAYERS; CHEMICAL REACTIONS; FLUID MECHANICS; MIXING; MIXING LAYERS (FLUIDS); NUMERICAL ANALYSIS; SIMULATION; SUPERSONIC FLOW; CHEBYSHEV APPROXIMATION; COMPUTER PROGRAMS; FINITE DIFFERENCE THEORY; HYPERSONIC AIRCRAFT; SUPERSONIC COMBUSTION RAMJET ENGINES...
Download or read book Annual Technical Report on Turbulent Reacting Flows and Supersonic Combustion written by C. T. Bowman and published by . This book was released on 1991 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research on Supersonic Reacting Rows written by and published by . This book was released on 1997 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental and computational investigation of supersonic combustion flows was carried out. The principal objective of the research was to gain a more fundamental understanding of mixing and chemical reaction in supersonic flows. The research effort comprised three inter-related elements: (1) stability analyses and numerical simulations of compressible reacting flows; (2) development of laser-induced fluorescence techniques for time-resolved multidimensional imaging of species concentration, temperature, velocity and pressure; and (3) an experimental study of mixing and combustion in a supersonic plane mixing layer with the additional development of simple mixing enhancements. The specific objectives and results of the research of each of these program elements have been summarized in this report. New results include: a detailed stability map for reacting, compressible shear layers; new PLIF techniques for transient facilities; new measurements of mixing efficiency in compressible flows and demonstration of simple mixing enhancement techniques with low pressure drop.
Download or read book Combustion in High Speed Flows written by John Buckmaster and published by Springer. This book was released on 1994-06-30 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the Workshop on Com bustion, sponsored by the Institute for Computer Applications in Science and Engineering (ICASE) and the NASA Langley Research Center (LaRC). It was held on October 12-14, 1992, and was the sec ond workshop in the series on the subject. The first was held in 1989, and its proceedings were published by Springer-Verlag under the title "Major Research Topics in Combustion," edited by M. Y. Hussaini, A. Kumar, and R. G. Voigt. The focus of the second workshop was directed towards the development, analysis, and application of basic models in high speed propulsion of particular interest to NASA. The exploration of a dual approach combining asymptotic and numerical methods for the analysis of the models was particularly encouraged. The objectives of this workshop were i) the genesis of models that would capture or reflect the basic pllysical phenomena in SCRAMJETs and/or oblique detonation-wave engines (ODWE), and ii) the stimulation of a greater interaction between NASA exper imental research community and the academic community. The lead paper by D. Bushnell on the status and issues of high speed propulsion relevant to both the SCRAMJET and the ODWE parallels his keynote address which set the stage of the workshop. Following the lead paper were five technical sessions with titles and chairs: Experiments (C. Rogers), Reacting Free Shear Layers (C. E. Grosch), Detonations (A. K. Kapila), Ignition and Struc ture (J. Buckmaster), and Unsteady Behaviour ('1'. L. Jackson).
Download or read book Investigation of Supersonic Chemically Reacting and Radiating Channel Flow written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-11-21 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 2-D time-dependent Navier-Stokes equations are used to investigate supersonic flows undergoing finite rate chemical reaction and radiation interaction for a hydrogen-air system. The explicit multistage finite volume technique of Jameson is used to advance the governing equations in time until convergence is achieved. The chemistry source term in the species equation is treated implicitly to alleviate the stiffness associated with fast reactions. The multidimensional radiative transfer equations for a nongray model are provided for a general configuration and then reduced for a planar geometry. Both pseudo-gray and nongray models are used to represent the absorption-emission characteristics of the participating species. The supersonic inviscid and viscous, nonreacting flows are solved by employing the finite volume technique of Jameson and the unsplit finite difference scheme of MacCormack. The specified problem considered is of the flow in a channel with a 10 deg compression-expansion ramp. The calculated results are compared with those of an upwind scheme. The problem of chemically reacting and radiating flows are solved for the flow of premixed hydrogen-air through a channel with parallel boundaries, and a channel with a compression corner. Results obtained for specific conditions indicate that the radiative interaction can have a significant influence on the entire flow field. Mani, Mortaza and Tiwari, Surendra N. CHANNEL FLOW; CHEMICAL REACTIONS; RADIATIVE HEAT TRANSFER; SUPERSONIC FLOW; AIR; DIMENSIONS; FINITE DIFFERENCE THEORY; FINITE VOLUME METHOD; HYDROGEN; INVISCID FLOW; NAVIER-STOKES EQUATION; TIME DEPENDENCE; VISCOUS FLOW...
Download or read book Uniform Supersonic Flows in Chemical Physics written by Bertrand R. Rowe and published by Wspc (Europe). This book was released on 2022 with total page 703 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioastronomy has painted an extraordinary picture of the Galactic interstellar medium, which displays an amazing organization and structuring of matter from very hot ultra-diluted media to very cold denser milieus considered as the cradles of stars. In these latter environments, the discovery of a chemical diversity of molecules, including those associated with precursors to life itself, immediately brought to light the question of the mechanisms leading to their formation and persistence at temperatures as low as 10 K. The chemical networks developed to understand telescope observations required a great deal of physical and chemical parameters relevant to interstellar conditions, particularly at very low temperatures. These included the rate coefficients of thousands of gas phase chemical reactions. Such data were missing in the 1970s, when the very first molecular discoveries were made. Then, in the early eighties, it was realized that uniform supersonic flows were ideal chemical reactors to study reaction kinetics at interstellar temperatures. Uniform Supersonic Flows in Chemical Physics reviews 40 years of use of such reactors, the so-called CRESU machines, focusing on major breakthroughs brought to chemical physics, physical chemistry, astrophysics and astrochemistry by the various experiments carried out with such apparatuses. The wealth of kinetic data at very low temperatures provided new targets for the predictions of theory, with new theoretical methods being developed to explain observed behavior. The first two chapters describe the physical context of reaction kinetics at very low temperatures and the requirements needed to run optimally such uniform supersonic flows, together with a historical perspective. Chapters 3 to 9 describe the various families of chemical processes that have been explored within the CRESU technique, highlighting major advances and offering an exhaustive up-to-date bibliography. Chapters 10 and 11 show how these experimental results have helped in improving the ideas in quantum chemistry and interstellar modeling. The book concludes with an overview of potential perspectives and new routes to be explored.
Download or read book High Speed Reacting Flows Research to Understand Processes in Supersonic Combustors written by H. Krier and published by . This book was released on 1987 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this program is to determine the fundamental fluid dynamic mechanisms occurring in the mixing and entrainment processes in the free shear layer formed between two high-speed (supersonic/sonic) streams. How the fluid mixing and subsequent combustion depends upon compressibility, as well as other parameters of the free shear layer process, is currently being investigated in an experimental study of the two-dimensional, compressible, turbulent reactive free shear layer. Use of non-intrusive, laser-based diagnostics including laser Schlieren for flow visualization, Laser Doppler Velocimetry (LDV) for velocity and turbulence measurement, and Planar Laser-Induced Fluorescence (PLIF) for temperature and concentration measurements are being employed.
Download or read book Investigation of Radiative Interactions in Supersonic Internal Flows written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-18 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analyses and numerical procedures are presented to study the radiative interactions of absorbing emitting species in chemically reacting supersonic flow in various ducts. The 2-D time dependent Navier-Stokes equations in conjunction with radiative flux equation are used to study supersonic flows undergoing finite rate chemical reaction in a hydrogen air system. The specific problem considered is the flow of premixed radiating gas between parallel plates. Specific attention was directed toward studying the radiative contribution of H2O, OH, and NO under realistic physical and flow conditions. Results are presented for the radiative flux obtained for different gases and for various combination of these gases. The problem of chemically reacting and radiating flows was solved for the flow of premixed hydrogen-air through a 10 deg compression ramp. Results demonstrate that the radiative interaction increases with an increase in pressure, temperature, amount of participating species, plate spacing, and Mach number. Most of the energy, however, is transferred by convection in the flow direction. In general the results indicate that radiation can have a significant effect on the entire flow field. Tiwari, Surendra N. and Thomas, A. M. Unspecified Center CHEMICAL REACTIONS; FLOW DISTRIBUTION; FUEL-AIR RATIO; HYDROXYL RADICALS; NITROGEN OXIDES; PREMIXING; REACTING FLOW; SUPERSONIC FLOW; CONVECTIVE FLOW; DUCTED FLOW; ENERGY TRANSFER; GAS FLOW; GAS MIXTURES; MACH NUMBER; NAVIER-STOKES EQUATION; PARALLEL PLATES; SPACING; TIME DEPENDENCE; WATER...
Download or read book 3 D Numerical Simulation of Supersonic Reacting Flows in Scramjet Combustor written by J. H. Liang and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 1996-11-30 with total page 442 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 Studies on Nonequilibrium Phenomena in Supersonic Chemically Reacting Flows written by Rajnish Chandrasekhar and published by . This book was released on 1993 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A multidomain spectral method for supersonic reactive flows written by and published by DIANE Publishing. This book was released on with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
