Download or read book Numerical Simulation of Cantilevered Ramp Injector Flow Fields for Hypervelocity Fuel air Mixing Enhancement written by 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 Numerical Simulation of Cantilevered Ramp Injector Flow Fields for Hypervelocity Fuel air Mixing Enhancement written by Jurgen Schumacher and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing demand for affordable access to space and high speed terrestrial transport has spawned research interest into various air-breathing hypersonic propulsion systems. Propulsion concepts such as the supersonic combustion ramjet (scramjet) and the shock-induced combustion ramjet (shcramjet) utilize oxygen freely available in the atmosphere and thereby substantially reduce the weight penalty of on-board oxidizer tankage used in rocket based systems. Of key importance to the ultimate success of an air-breathing concept is the ability to efficiently mix the fuel with atmospheric air. In the case of a hypersonic air-breather the challenge is accentuated due to the requirement of supersonic combustion. Flow velocities through the combustor on the order of thousands of meters per second provide the fuel and air with only a brief time to adequately combine. Contemporary mixing augmentation methods to address this issue have focused on fuel injection devices which promote axial vortices to enhance the mixing process. Much research effort has been expended on investigation of ramp injectors for this purpose. The present study introduces a new ramp injector design, based on the conventional ramp injector, dubbed the cantilevered ramp injector. A two-pronged numerical approach was employed to investigate the mixing performance and characteristics of the cantilevered injector consisting of, (1) comparison with conventional designs and (2) a parametric study of various cantilevered injector geometries. A laminar, three-dimensional, multispecies flowsolver was developed in generalized coordinates to solve the Navier-Stokes equations for the flow fields of injected H2 into high-enthalpy air. The scheme consists of an upwind TVD scheme for discretization of the convective fluxes coupled with a semi-implicit LU-SGS scheme for temporal discretization. Through analysis of the numerical solutions, it has been shown that the cantilevered ramp injector is a viable fuel injection system facilitating enhanced mixing of fuel and air. Comparison with conventional designs have revealed a competitive and, in most cases, superior design in the context of mixing performance. A strong counter-rotating vortex pair generated under the cantilevered injector was shown to be the distinguishing characteristic of this design and largely accounted for improved mixing performance. Results also elucidated the importance of a coupled design approach between the fuel injector and propulsive duct to optimize mixing performance.

Download or read book Numerical Simulation of Cantilevered Ramp Injector Flow Fields for Hypervelocity Fuel written by Jurgen Schumacher and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2000 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combustion of the Fuel air Mixture in the Vicinity of a Cantilevered Ramp Fuel Injector in a Hypervelocity Flow written by Viorel Turcu and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The flow field in the immediate vicinity of a cantilevered ramp fuel injector is investigated in order to determine whether premature ingition occurs while the fuel/air mixing process is taking place. Two configurations of cantilevered ramp injectors are studied: the "A" configuration injector (with non-zero compression and expansion angles), and the "B" configuration injector (with zero compression angle and non-zero expansion angle). The study was conducted using a laminar, three-dimensional, multispecies flowsolver developed in generalized coordinates to solve the Navier-Stokes equations with hydrogen/air finite rate chemistry. The method consists of an upwind TVD scheme for the discretization of the convective fluxes coupled with a semi-implicit LU-SGS scheme for temporal discretization. The finite-rate chemistry model chosen for the present study includes 9 species (H2, O2, H, O, OH, H2O, HO2, and N2) and 20 reactions. The chemical solver assumes that the nitrogen is inert, which is a valid assumption when the static temperatures do not exceed 3000 K. The analysis of the numerical solutions shows that premature ignition occurs for both configurations considered in the present study. The fuel is ignited by the hot air which is raising from the boundary layers corresponding to the lower wall of the channel that contains the fuel injectors.

Download or read book Investigation of Ramp Injectors for Supersonic Mixing Enhancement written by Y. Haimovitch and published by . This book was released on 1994 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Ramp Injectors for Supersonic Mixing Enhancement written by Y. Haimovitch and published by . This book was released on 1994 with total page 260 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 39th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit July 20 23 2003 Huntsville Alabama 03 5150 03 5199 written by and published by . This book was released on 2003 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combustion of the Fuel air Mixture in the Vicinity of a Cantilevered Ramp Fuel Injector in a Hypervelocity Flow written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2006 with total page 1380 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book American Doctoral Dissertations written by and published by . This book was released on 2000 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Ramp Injectors for Supersonic Mixing Enhancement written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-25 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comparative study of wall mounted swept ramp injectors fitted with injector nozzles of different shape has been conducted in a constant area duct to explore mixing enhancement techniques for scramjet combustors. Six different injector nozzle inserts, all having equal exit and throat areas, were tested to explore the interaction between the preconditioned fuel jet and the vortical flowfield produced by the ramp: circular nozzle (baseline), nozzle with three downstream facing steps, nozzle with four vortex generators, elliptical nozzle, tapered-slot nozzle, and trapezoidal nozzle. The main flow was air at Mach 2, and the fuel was simulated by air injected at Mach 1.63 or by helium injected at Mach 1.7. Pressure and temperature surveys, combined with Mie and Rayleigh scattering visualization, were used to investigate the flow field. The experiments were compared with three dimensional Navier-Stokes computations. The results indicate that the mixing process is dominated by the streamwise vorticity generated by the ramp, the injectors' inner geometry having a minor effect. It was also found that the injectant/air mixing in the far-field is nearly independent of the injector geometry, molecular weight of the injectant, and the initial convective Mach number. Haimovitch, Y. and Gartenberg, E. and Roberts, A. S., Jr. Unspecified Center NASA-CR-4634, NAS 1.26:4634 NAS1-19858; RTOP 505-70-62-12...

Download or read book Progress Report on Research Supported by Grants from the Defense Research Board of Canada written by University of Toronto. Institute for Aerospace Studies and published by . This book was released on 2000 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2001 with total page 810 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental and Numerical Study of Ramp Injectors for Supersonic Fuel air Mixing written by James M. Donohue and published by . This book was released on 1995 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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