Unsteady Processes in Solid Propellant Combustion PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Unsteady Processes in Solid Propellant Combustion PDF full book. Access full book title Unsteady Processes in Solid Propellant Combustion by A. Crespo. Download full books in PDF and EPUB format.
Author: A. Crespo
Publisher:
ISBN:
Category :
Languages : en
Pages : 43
Get Book Here
Book Description
The purpose of this work is to develop a theoretical analysis of unsteady processes in solid propellant combustion, particularly combustion stability and extinction by rapid depressurization. It is assumed that the solid decomposes at its surface by a pyrolysis law, and the gaseous decomposition products react exothermically following an Arrenius law. The nondimensional activation energy of the gas phase reaction is considered to be large so that the reaction takes place in a thin zone where the temperature is close to the flame temperature. The gas phase is assumed to be quasisteady and under this condition the equations in the gas phase are solved in the limit of high activation energies. The analysis of the energy equation in the condensed phase shows that the characteristic response time of the solid to gas phase perturbations is large compared to the characteristic residence time in the heat-up zone of the solid, their ratio being of the order the nondimensional activation energy in the gas phase reaction. A stability criterion has been obtained, resulting that for large values of the nondimensional activation energy of the pyrolysis law there is always unstable behaviour. For the stable case the dynamic extinction problem is being presently investigated. (Author).
Author: A. Crespo
Publisher:
ISBN:
Category :
Languages : en
Pages : 43
Get Book Here
Book Description
The purpose of this work is to develop a theoretical analysis of unsteady processes in solid propellant combustion, particularly combustion stability and extinction by rapid depressurization. It is assumed that the solid decomposes at its surface by a pyrolysis law, and the gaseous decomposition products react exothermically following an Arrenius law. The nondimensional activation energy of the gas phase reaction is considered to be large so that the reaction takes place in a thin zone where the temperature is close to the flame temperature. The gas phase is assumed to be quasisteady and under this condition the equations in the gas phase are solved in the limit of high activation energies. The analysis of the energy equation in the condensed phase shows that the characteristic response time of the solid to gas phase perturbations is large compared to the characteristic residence time in the heat-up zone of the solid, their ratio being of the order the nondimensional activation energy in the gas phase reaction. A stability criterion has been obtained, resulting that for large values of the nondimensional activation energy of the pyrolysis law there is always unstable behaviour. For the stable case the dynamic extinction problem is being presently investigated. (Author).
Author: Leonard H. Caveny
Publisher:
ISBN:
Category :
Languages : en
Pages : 40
Get Book Here
Book Description
The research carried out under the grant was aimed at furthering the scientific understanding of nonsteady propellant combustion behavior in rocket motor chambers. Controlled nonsteady flow and burning conditions were produced in laboratory-scale solid rocket motors by developing a device that modulated the throat area of the primary nozzle. Modulation frequencies up to 2400 Hz were obtained. The modulated throat rocket motor is being used to acquire data using AP composite propellant grains. Cold flow tests were used to study the acoustic modes and nozzle discharge characteristics. Computerized techniques were developed for conducting spectral analyses of head-end and nozzle-end pressure data. In addition, the equations describing the nonsteady one-dimensional gas dynamics and propellant combustion were formulated, and a comprehensive numerical solution was developed. The present solution takes into account the couplings among the oscillating nozzle flow, the nonsteady chamber flow, and erosive burning. Since pressure and velocity oscillations can be made to occur and decay in high loading density rocket motors with realistic grain configurations, the experiment is expected to produce propellant/chamber response functions that are relatively easy to interpret, compared to the difficult to interpret T-burner response functions.
Author: Vasily B. Novozhilov
Publisher: John Wiley & Sons
ISBN: 1119525640
Category : Technology & Engineering
Languages : en
Pages : 352
Get Book Here
Book Description
Despite significant developments and widespread theoretical and practical interest in the area of Solid-Propellant Nonsteady Combustion for the last fifty years, a comprehensive and authoritative text on the subject has not been available. Theory of Solid-Propellant Nonsteady Combustion fills this gap by summarizing theoretical approaches to the problem within the framework of the Zeldovich-Novozhilov (ZN-) theory. This book contains equations governing unsteady combustion and applies them systematically to a wide range of problems of practical interest. Theory conclusions are validated, as much as possible, against available experimental data. Theory of Solid-Propellant Nonsteady Combustion provides an accurate up-to-date account and perspectives on the subject and is also accompanied by a website hosting solutions to problems in the book.
Author: Leonard H. Caveny
Publisher:
ISBN:
Category :
Languages : en
Pages : 52
Get Book Here
Book Description
Nonsteady propellant combustion and chamber flow behavior, particularly as they relate to combustion stability and aluminized propellant combustion are being studied. The first part of the study is centered around the modulated throat rocket motor which is being developed to investigate the dynamic responses of high performance rocket motors in which externally excited longitudinal pressure and velocity waves produce coupling with propellant combustion processes. Transfer functions between the measured head-end and nozzle-end pressures produce gain and phase information in the vicinity of the first 3 harmonics.
Author: Vasily B. Novozhilov
Publisher: John Wiley & Sons
ISBN: 1119525586
Category : Technology & Engineering
Languages : en
Pages : 352
Get Book Here
Book Description
Despite significant developments and widespread theoretical and practical interest in the area of Solid-Propellant Nonsteady Combustion for the last fifty years, a comprehensive and authoritative text on the subject has not been available. Theory of Solid-Propellant Nonsteady Combustion fills this gap by summarizing theoretical approaches to the problem within the framework of the Zeldovich-Novozhilov (ZN-) theory. This book contains equations governing unsteady combustion and applies them systematically to a wide range of problems of practical interest. Theory conclusions are validated, as much as possible, against available experimental data. Theory of Solid-Propellant Nonsteady Combustion provides an accurate up-to-date account and perspectives on the subject and is also accompanied by a website hosting solutions to problems in the book.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 268
Get Book Here
Book Description
Experimental and analytical investigations were conducted to understand the ignition and nonsteady burning processes that occur at and near the propellant surface, to determine the connection between the ignitability of a propellant and its other nonsteady combustion characteristics, to quantify the peculiarities of radiative ignition, and to develop a means of ranking propellant ignitability. As a result of these investigations, radiative ignition processes have been explained for a wide variety of propellant and test conditions. The stability properties of heterogeneous combustion waves were considered for linear and nonlinear situations. Nonlinear (large disturbances) solid propellant stability boundaries can be immediately defined from the knowledge of the associated restoring function. The restoring function is a property strictly dependent on the nature of the solid propellant.
Author: Qibo Jing
Publisher:
ISBN:
Category : Chemical kinetics
Languages : en
Pages : 149
Get Book Here
Book Description
Author: F. Culick
Publisher: Springer Science & Business Media
ISBN: 9400916205
Category : Technology & Engineering
Languages : en
Pages : 560
Get Book Here
Book Description
This book contains selected papers prepared for the NATO Advanced Study Institute on "Unsteady Combustion", which was held in Praia da Granja, Portugal, 6-17 September 1993. Approximately 100 delegates from 14 countries attended. The Institute was the most recent in a series beginning with "Instrumentation for Combustion and Flow in Engines", held in Vimeiro, Portugal 1987 and followed by "Combusting Flow Diagnostics" conducted in Montechoro, Portugal in 1990. Together, these three Institutes have covered a wide range of experimental and theoretical topics arising in the research and development of combustion systems with particular emphasis on gas-turbine combustors and internal combustion engines. The emphasis has evolved roughly from instrumentation and experimental techniques to the mixture of experiment, theory and computational work covered in the present volume. As the title of this book implies, the chief aim of this Institute was to provide a broad sampling of problems arising with time-dependent behaviour in combustors. In fact, of course, that intention encompasses practically all possibilities, for "steady" combustion hardly exists if one looks sufficiently closely at the processes in a combustion chamber. The point really is that, apart from the excellent paper by Bahr (Chapter 10) discussing the technology of combustors for aircraft gas turbines, little attention is directed to matters of steady performance. The volume is divided into three parts devoted to the subjects of combustion-induced oscillations; combustion in internal combustion engines; and experimental techniques and modelling.
Author: Pil-kyu Kim
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 418
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 77
Get Book Here
Book Description
The model of uniformly distributed combustion in the gas phase is used as the basis for examining several features of unsteady burning. As a zeroth approximation the flame zone begins at the solid-gas interface and responds linearly and quasi-statistically to changes of pressure only. Three deviations from this behavior are then examined: the combustion zone is displaced from the surface, the energy release responds to fluctuations of temperature and the response is not quasi-static. It appears that the assumption that the burning begins immediately at the surface can lead to significant changes, more important than the assumption that the energy release responds to changes of pressure only, especially in the interpretation of experimental data. The problem of nonquasi-static behavior, i.e., processes in the gas phase do not follow precisely impressed changes of pressure, is formulated as an expansion in frequency. Approximate results seem to be consistent with existing information.
