Download or read book Coaxial Dump Ramjet Combustor Combustion Instabilities written by D. L. Davis and published by . This book was released on 1981 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report contains Combustion Instability Data for Coaxial Dump Ramjet Combustors. The data includes pressure vs. time, RMS pressure spectrums, peak and broadband RMS pressures, and related steady state performance data. Analysis and interpretation of the data are reserved for future reports. Also included is a description of RMS pressure and its relation to wave shape.
Download or read book Coaxial Dump Ramjet Combustor Combustion Instabilities Part I Parametric Test Data written by D. L. Davis and published by . This book was released on 1981 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report contains Combustion Instability Data for Coaxial Dump Ramjet Combustors. The data includes pressure vs. time, RMS pressure spectrums, peak and broadband RMS pressures, and related steady state performance data. Analysis and interpretation of the data are reserved for future reports. Also included is a description of RMS pressure and its relation to wave shape. (Author).
Download or read book Combustion Instabilities in Single Inlet Coaxial Dump Combustors driving damping Mechanisms written by Netzer and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Hart Cantrel Model Combustion Instabilities in Single Inlet Coaxial Dump Combustors driving damping Mechanisms written by Zinn and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flame Driving of Longitudinal Instabilities in Liquid Fueled Dump Combustors written by Ben T. Zinn and published by . This book was released on 1987 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the results of experimental and theoretical investigations of the mechanisms by which the core flow combustion process in coaxial, single inlet, dump type ramjet engines drives longitudinal combustion instabilities. To this end, the behavior of V-shaped flames, similar to those often occurring in ramjet combustors, stabilized in longitudinal acoustic fields has been studied. The presence of burning vortical structures is observed in the flame region. These structures appear at frequencies close to the first natural acoustic frequency of the combustor and are believed to be connected with a shear layer type of instability of the flame. Experiments conducted show that the unsteady combustion in these structures is capable of driving the acoustics at the fundamental acoustic mode frequency. With increase in fuel air ratio, a spontaneous instability involving the fundamental mode is observed and explained in terms of increased driving associated with the higher, unsteady heat release rates. The results of experiments conducted with external acoustic excitation of the flame at different frequencies are also reported and confirm the idea that the vortical structures arise due to a fluid mechanical instability of the flame. It is shown that the interactions between the vortical structures and the system's acoustic field affect the heat release rates from the flame and provide a mechanism for the driving of longitudinal mode instabilities. Keywords: Coaxial dump type ramjet, Flame driving, Combustion, Acoustics longitudinal instability, Vortex shedding, Shear layer instability.
Download or read book Ramjet Combustor Instabilities written by Luc Bauwens and published by . This book was released on 1989 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dump Combustor Parametric Investigation written by Frank D. Stull and published by . This book was released on 1974 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of scale model coaxial dump combustors from 2 inch to 5 inch D were tested on a thrust stand with JP-4 fuel over a wide range of ramjet test conditions. Baseline conditions were selected to approximate 'pressure scaling criteria' in which chamber pressure times combustor diameter remains constant. JP-4 fuel was injected perpendicular to the airstream from eight plane tube injectors. Fuel/air ratio, chamber pressure and nozzle throat diameter were varied for each size chamber. Lean blow-out limit, combustion efficiency, combustor pressure drop, and combustion instability characteristics were obtained for each test point.
Download or read book Low Frequency Pressure Oscillations in a Model Ramjet Dump Combustor written by Kenneth Hyupsang Yu and published by . This book was released on 1989 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulations of the Flowfield in Central Dump Ramjet Combustors 2 Effects of Inlet and Combustor Acoustics written by K. Kailasanath and published by . This book was released on 1988 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: A potentially important source of large pressure oscillations in compact ramjets is a combustion instability induced by the interaction of large-scale vortex structures with the acoustic modes of the ramjet. To study these interactions, we have performed time-dependent, compressible numerical simulations of the flow field in an idealized ramjet consisting of an axisymmetric inlet and a combustor. The simulations indicate strong coupling between the flow field and the acoustics of both the inlet and the combustor. For the cases studied, forcing at the first longitudinal acoustic mode of the combustor induces vortex-rollup near the entrance to the combustor at that frequency. A low frequency oscillation is also observed in all the simulations. Pressure and velocity fluctuations in the inlet indicate that the low frequency corresponds to a quarter-wave mode in the inlet. Changing the length of the inlet appropriately changes the observed low frequency. The merging pattern of the inlet is changed. These merging patterns are explained on the basis of an interaction between the vortex-rollup frequency and the acoustic modes of the inlet and combustor. Keywords: Ramjet, Combustion instability, Turbulence. (mjm).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unsteady Combustor Physics written by Tim C. Lieuwen and published by Cambridge University Press. This book was released on 2012-08-27 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with unsteady combustor issues, which have posed key challenges associated with development of clean, high-efficiency combustion systems.
Download or read book A Low frequency Instability Mechanism in a Coaxial Dump Combustor written by John Adam Keklak and published by . This book was released on 1981 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluid Mechanically Coupled Combustion instabilities in Ramjet Combustors written by U. G. Hegde and published by . This book was released on 1987 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large eddy Simulations of Combustion Instability in an Axisymmetric Ramjet Combustor written by Suresh Menon and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion Efficiency in a Dual inlet Side dump Ramjet Combustor written by Martin W. Deppe and published by . This book was released on 1994 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: A dual, axially-in-line, side-dump, liquid-fueled ramjet combustor was designed and tested with varying fuel-air ratios, atomizer types, and air distributions between the two inlets. Particle size distributions produced by the atomizers were measured at the inlet duct plane. When operated in a contra- flow direction, all of the atomizers produced excellent atomization with a Sauter mean diameter less than 14 microns. The dual, in-line inlets provided improved flammability limits and combustion efficiencies at lean fuel-air ratios when compared to single side-dump performance. Direct injection of approximately 20% of the fuel flow into the dome region was found to provide improved lean flammability limits for the single side-dump, but was not required with the dual inlets. The fuel distribution in the inlet duct required for good flammability limits and combustion efficiency was opposite to that required to prevent pressure oscillations, indicating that a dump plane aero-grid will often be necessary. A dump angle of 45 deg resulted in lower than desired combustion efficiencies, apparently due to poor mixing with the air from the aft inlet.
Download or read book Thermoacoustic Combustion Instability Control written by Dan Zhao and published by Academic Press. This book was released on 2023-02-13 with total page 1145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermoacoustic Combustion Instability Control: Engineering Applications and Computer Codes provides a unique opportunity for researchers, students and engineers to access recent developments from technical, theoretical and engineering perspectives. The book is a compendium of the most recent advances in theoretical and computational modeling and the thermoacoustic instability phenomena associated with multi-dimensional computing methods and recent developments in signal-processing techniques. These include, but are not restricted to a real-time observer, proper orthogonal decomposition (POD), dynamic mode decomposition, Galerkin expansion, empirical mode decomposition, the Lattice Boltzmann method, and associated numerical and analytical approaches. The fundamental physics of thermoacoustic instability occurs in both macro- and micro-scale combustors. Practical methods for alleviating common problems are presented in the book with an analytical approach to arm readers with the tools they need to apply in their own industrial or research setting. Readers will benefit from practicing the worked examples and the training provided on computer coding for combustion technology to achieve useful results and simulations that advance their knowledge and research. Focuses on applications of theoretical and numerical modes with computer codes relevant to combustion technology Includes the most recent modeling and analytical developments motivated by empirical experimental observations in a highly visual way Provides self-contained chapters that include a comprehensive, introductory section that ensures any readers new to this topic are equipped with required technical terms
Download or read book Turbulent Combustion Modelling in a Side Dump Ramjet Combustor written by X. Montazel and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
