[PDF] Nonsteady Burning And Combustion Stability Of Solid Propellants eBook

Author : Martin Summerfield
Publisher :
Page : 13 pages
File Size : 28,69 MB
Release : 1968
Category :
ISBN :

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The overall objective of the research program has been to study the non-steady burning characteristics of solid rocket propellants, both experimentally and theoretically, to establish a basis for avoiding combustion instability in rocket motors and for predicting thrust transients during motor ignition and extinction. A new non-steady burning model for composite propellants was formulated in which the key element, the non-steady heat feedback law from the gaseous flame, was shown to be a function of the instantaneous pressure and burning rate. Solutions to this model showed that burning stability is largely determined by the exothermicity of reactions in the immediate neighborhood of the propellant surface and by the sensitivity of burning rate to surface temperature. The predictions of the model were generally confirmed by T-motor and rapid pressurization experiments. The non-steady burning model was also used to analyze L-star combustion instability in rocket motors and to demonstrate the feasibility of a novel mechanism for suppression of combustion instability by aluminum addition to a propellant. (Author).

Author : Vasily B. Novozhilov
Publisher : John Wiley & Sons
Page : 352 pages
File Size : 48,57 MB
Release : 2020-08-21
Category : Technology & Engineering
ISBN : 1119525640

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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 :
Page : 54 pages
File Size : 40,19 MB
Release : 1978
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ISBN :

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A theoretical analysis is presented of unsteady solid propellant combustion, particularly combustion stability and extinction by rapid depressurization. It is assumed that the solid decomposes by a pyrolosis law and the gaseous products react exothermically following an Arrhenius law. For large values of this non-dimensional activation energy the gas-phase combustion, turns out to be quasisteady. The characteristic response time of the solid to gas-phase perturbations turns out to be large compared to the characteristic residence time in the heat-up zone of the solid, their ratio being of the order of the non-dimensional activation energy in the gas-phase. A linear stability criterion has been obtained that gives stable burning for steady burning rates above and below two limiting values; the width of the unstable region increases with the activation energy of the pyrolisis law, and becomes zero for a finite value of that activation energy.

Author : Herman Krier
Publisher :
Page : 38 pages
File Size : 44,2 MB
Release : 1966
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A prominent mode of coupling that may drive a solid propellant rocket motor into instability is the interaction between the oscillatory gas dynamic pressure at the burning surface and the instantaneous rate of the oscillatory pressure fluctuations and of rapid monotonic pressure increases are being investigated in a continuing program. Two pieces of apparatus are in use for this purpose. One is the T-tube oscillator. The latter is a chamber with a device to change suddenly on command the throat area of the nozzle to produce pressure rise times of 8,000 psi per second and less. This low range supplements the higher range achievable in the T-tube oscillator. The chamber has three quartz windows which allow luminosity measurements and high speed motion pictures of the propellant flame to be made along with chamber pressure. By varying the chamber volume, and thereby the dp/dt, luminosity versus pressure can be obtained as a function of dp/dt. From this, the temperature is plotted as a function of pressure and dp/dt, and therefore the entropy is plotted as a function of the same variables. The brightness-emissivity method of instantaneous flame temperature measurement is being used. Experiments are being conducted to determine the flame temperature as a function of pressure in various regimes of dp/dt. (Author).

Author : Louis A. Povinelli
Publisher :
Page : 60 pages
File Size : 37,60 MB
Release : 1969
Category : Chemical kinetics
ISBN :

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Pressure and velocity coupling effects on combustion stability in solid propellant burning.

Author : R. H. WOODWARD
Publisher :
Page : 1 pages
File Size : 16,70 MB
Release : 1961
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A fundamental study of the non-steady combustion of solid propellants with application to rocket instability is described. A film strip of a metallized solid propellant burning in an oscillating pressure field was analyzed in order to determine the phase relationship between the imposed pressure maxima and an apparent wave of luminosity in the combustion gases. The implications of these observations as they affect the model of the burning propellant are briefly considered. Two types of experimental observation which will be used to study non-steady combustion are outlined. One method involves the measurement of the temperature of the combustion gases downstream from the flame zone. The use of a particle track method for the observation of pressure-velocity relationships in the burnt gases is also considered. (Author).

Author :
Publisher :
Page : 19 pages
File Size : 15,67 MB
Release : 1997
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This report describes progress on a collaborative research program combining the expertise of individuals from several universities to develop a new ability to predict the propulsion performance of solid rocket motors. The focus of the research on nonsteady behavior is unique and the overall project is not possible at any one of the institutions participating in this coordinated research. The individual tasks which we are studying will pursue solid propellant decomposition under unsteady conditions, nonsteady aspects of gas phase flame structure measurements, numerical modeling of multidimensional flame structure, propellant/flame interactions and overall nonsteady propellant combustion characteristics in realistic rocket motor environments. Our goal has been to develop general models of fundamental mechanisms of combustion instability that can be applied to a variety of new energetic materials.

Author : Vasily B. Novozhilov
Publisher : John Wiley & Sons
Page : 352 pages
File Size : 20,83 MB
Release : 2020-09-15
Category : Technology & Engineering
ISBN : 1119525705

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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.