Download or read book Simulation of Turbulent Hypersonic Flows written by Graham V. Candler and published by . This book was released on 1997 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct numerical simulations of turbulent reacting flows were performed to study the interaction between chemical heat release and turbulent fluid motion. A portion of the energy released by exothermic reactions is placed in the compressible mode of turbulent kinetic energy, with very little energy disposed to the incompressible mode. This process results in a positive feedback mechanism, whereby temperature fluctuations are amplified by the chemical reactions. In the case of endothermic reactions, the feedback is negative, resulting in decreased turbulent motion. The results of the simulations were used to develop a model for temperature fluctuations under conditions typical of a hypersonic boundary layer. This model has been validated and is suitable for use in the large eddy simulation of hypersonic turbulent boundary layers.
Download or read book Numerical Simulation of Turbulent Shock boundary layer Interactions in Hypersonic Flows written by Turan Coratekin and published by . This book was released on 2000 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence Modeling for Hypersonic Flows written by Joseph G. Marvin and published by . This book was released on 1989 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence and Transition in Supersonic and Hypersonic Flows written by Johan Larsson and published by Academic Press. This book was released on 2025-09-01 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence and Transition in Supersonic and Hypersonic Flows explains how to understand and mathematically model these phenomena, with an emphasis on the unique challenges and features that the compressibility of the fluid introduces. This timely book responds to an increase in research interest in this topic, explaining how to use the latest numerical methods as well as providing important background theory. It covers both the problem of how a laminar boundary layer transitions to turbulence in the supersonic and hypersonic regime and the problem of how compressibility of a fluid affects turbulence. Compressible flows are important in many areas of engineering, including external aerodynamics, internal flows in propulsion and power generation applications, flows in supercritical fluids, and many others.
Download or read book Advances in Hypersonics written by Bertin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: These three volumes entitled Advances in Hypersonics contain the Proceedings of the Second and Third Joint US/Europe Short Course in Hypersonics which took place in Colorado Springs and Aachen. The Second Course was organized at the US Air Force Academy, USA in January 1989 and the Third Course at Aachen, Germany in October 1990. The main idea of these Courses was to present to chemists, com puter scientists, engineers, experimentalists, mathematicians, and physicists state of the art lectures in scientific and technical dis ciplines including mathematical modeling, computational methods, and experimental measurements necessary to define the aerothermo dynamic environments for space vehicles such as the US Orbiter or the European Hermes flying at hypersonic speeds. The subjects can be grouped into the following areas: Phys ical environments, configuration requirements, propulsion systems (including airbreathing systems), experimental methods for external and internal flow, theoretical and numerical methods. Since hyper sonic flight requires highly integrated systems, the Short Courses not only aimed to give in-depth analysis of hypersonic research and technology but also tried to broaden the view of attendees to give them the ability to understand the complex problem of hypersonic flight. Most of the participants in the Short Courses prepared a docu ment based on their presentation for reproduction in the three vol umes. Some authors spent considerable time and energy going well beyond their oral presentation to provide a quality assessment of the state of the art in their area of expertise as of 1989 and 1991.
Download or read book A Discrete Adjoint Framework for Turbulent Hypersonic Flows in Thermochemical Nonequilibrium written by Walter Thomas Maier and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypersonic vehicle design and analysis continues to challenge the aerospace community. These systems operate in a unique flow environment characterized by thermochemical nonequilibrium effects, adding constraints and complexity not observed in other flow regimes. Numerical simulations must resolve these high-temperature, atomic-scale physical phenomena to accurately predict vehicle performance parameters such as lift, drag, control authority, and surface heat transfer. As a result, expensive CFD simulation models are substituted with low-fidelity correlation-based models in the design process. This yields, at best conservative vehicle configurations and, at worst, failed designs. Consequently, despite the rapid growth of computational power, hypersonic vehicle design has stagnated without the proper methods to efficiently incorporate CFD into the design process. This dissertation presents, to the author's knowledge, the first discrete adjoint framework for the efficient computation of aerothermodynamic sensitivities of turbulent hypersonic flows in thermochemical nonequilibrium to reintegrate high-fidelity simulations into the preliminary design phases for hypersonic vehicle systems.
Download or read book Validation of CFD Simulations for Hypersonic Flow Over a Yawed Circular Cone written by Julian D. Cecil and published by . This book was released on 2018 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study aims to numerically simulate the wind tunnel results for hypersonic flow over a circular cone of semi-apex angle of 10 degrees yawed from 0° to 20° using the commercial computational fluid dynamics software ANSYS Fluent. The ANSYS workbench is used to create the 10° semi-apex circular cone with a shock aligned structured mesh of 3.05 million cells surrounding the cone. Simulation boundary conditions for pressure and temperature in the far field correspond to Tracy's wind tunnel experiment at Cal Tech. The six simulations cases are conducted for yaw angles of 0, 8, 12, 16, 20 and 24 degrees. The unsteady Reynolds-Averaged compressible Navier-Stokes solver with Spalart-Allmaras (SA) turbulence model is employed. The upstream flow Mach number is M = 8 and Reynolds number is Re00 = 4.2 x105 based on cone generator length. The maximum variation in static pressure computations around the cone is 7% of the experimental values and the maximum variation in heat transfer computations is within 12% of the experimental values; the maximum difference between the computations and experiment occurs at the leeward meridian of the cone. By further refinement of the mesh and using other turbulence models, it is possible that computational accuracy of the simulations may be further improved; however it requires additional investigation. Nevertheless the present simulations demonstrate that CFD can be employed with sufficient accuracy to compute the hypersonic flows about space vehicles with fully turbulent flow.
Download or read book Modeling of Turbulence for Hypersonic Flows with and Without Separation written by S. T. Vuong and published by . This book was released on 1987 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation of Hypersonic Aerodynamics and the Computational Needs for the Design of an Aerospace Plane written by Shiao-kung Liu and published by . This book was released on 1992 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Some Aspects of Air helium Simulation and Hypersonic Approximations written by Eugene S. Love and published by . This book was released on 1959 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shock Wave Boundary Layer Interactions written by Holger Babinsky and published by Cambridge University Press. This book was released on 2011-09-12 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.
Download or read book Documentation of Two and Three dimensional Hypersonic Shock Wave turbulent Boundary Layer Interaction Flows written by Marvin I. Kussoy and published by . This book was released on 1989 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Shear Layers in Supersonic Flow written by Alexander J. Smits and published by Springer Science & Business Media. This book was released on 2006-05-11 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: A good understanding of turbulent compressible flows is essential to the design and operation of high-speed vehicles. Such flows occur, for example, in the external flow over the surfaces of supersonic aircraft, and in the internal flow through the engines. Our ability to predict the aerodynamic lift, drag, propulsion and maneuverability of high-speed vehicles is crucially dependent on our knowledge of turbulent shear layers, and our understanding of their behavior in the presence of shock waves and regions of changing pressure. Turbulent Shear Layers in Supersonic Flow provides a comprehensive introduction to the field, and helps provide a basis for future work in this area. Wherever possible we use the available experimental work, and the results from numerical simulations to illustrate and develop a physical understanding of turbulent compressible flows.
Download or read book Turbulence Modeling for Hypersonic Flows written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-15 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence modeling for high speed compressible flows is described and discussed. Starting with the compressible Navier-Stokes equations, methods of statistical averaging are described by means of which the Reynolds-averaged Navier-Stokes equations are developed. Unknown averages in these equations are approximated using various closure concepts. Zero-, one-, and two-equation eddy viscosity models, algebraic stress models and Reynolds stress transport models are discussed. Computations of supersonic and hypersonic flows obtained using several of the models are discussed and compared with experimental results. Specific examples include attached boundary layer flows, shock wave boundary layer interactions and compressible shear layers. From these examples, conclusions regarding the status of modeling and recommendations for future studies are discussed. Marvin, J. G. and Coakley, T. J. Ames Research Center RTOP 505-60-11...
Download or read book An Integrated Computational Tool for Hypersonic Flow Simulation written by and published by . This book was released on 2000 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of a computational tool for the solution of turbulent magnetohydrodynamic (MHD) equations, including turbulence or chemically reacting flows is presented. For the MHD solver, option is provided to solve either the full MHD equations or the low magnetic Reynolds number equations. For turbulence, the Reynolds Averaged approach is considered for its low requirement in terms of computational resources. Six turbulence models, ranging from simple algebraic model to more sophisticated two-equation models are considered to evaluate the eddy viscosity. Since the turbulence models were originally designed for non-magnetic flows, they require some modifications to account for the presence of a magnetic field. The governing equations are numerically solved by a modified Runge-Kutta scheme augmented with a Total Variation Diminishing scheme for accurate shock capturing. The numerical solutions are compared with available experimental data and existing analytical solutions. For the simulation of hypersonic high-temperature effects, two chemical models are utilized, namely a nonequilibrium model and an equilibrium model. A loosely coupled approach is implemented to communicate between the magnetogasdynamic equations and the chemical models. The nonequilibrium model is a one-temperature, five-species, seventeen-reaction model solved by an implicit flux-vector splitting scheme. The effectiveness of the chemical models for hypersonic flow over blunt body is examined in various flow conditions. It is shown that the proposed schemes perform well in a variety of test cases, though some limitations have been identified.
Download or read book Numerical Studies of Low Density Two Dimensional Hypersonic Flows by Using the Navier Stokes and Burnett Equations with Nonequilibrium Real Gas Effects written by and published by . This book was released on 1997 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this research is to study the laminar turbulent transition and other transient flow phenomena of 3-D chemically reacting hypersonic boundary layers by direct numerical simulation (DNS) and by linear stability analysis. The research in the report period was focused on developing new numerical methods for such studies and studying several fundamental transient hypersonic flow phenomena. First, several new efficient and high-order accurate numerical methods for DNS of 3-D hypersonic reacting boundary layers and for computing unsteady hypersonic flows with complex shock interactions were developed. These new methods were developed in order to overcome difficulties associated with the direct numerical simulation of hypersonic flows. Second, several studies on the stability phenomena of hypersonic boundary layers over blunt leading edges both by direct numerical simulation and by linear stability analyses were performed. Also completed were extensive numerical studies on real gas effects on a steady shock/boundary layer interaction and a self-sustained unsteady shock-shock interference heating flows. Third, the effects of using Burnett equations for rarefied hypersonic flow computations were investigated. With the completion of the bulk of work on the development of new numerical methods for complex hypersonic flow simulation, the DNS studies are currently being extended to 3-D hypersonic boundary layer transition over elliptic cross section cones.
Download or read book DNS and the LES Closure of Reacting Turbulence in Hypersonic Flows written by María del Pino Martín Aguirre and published by . This book was released on 1999 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
