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Burn rate (chemistry)

About: Burn rate (chemistry) is a research topic. Over the lifetime, 847 publications have been published within this topic receiving 8908 citations. The topic is also known as: Burning rate.


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Journal ArticleDOI
01 Jan 2017
TL;DR: In this paper, the results of the vibrational combustion modeling in terms of gas explosion in the cylinder with an opening on the side were presented. And the results showed that along with the pressure fluctuation there is burning area size fluctuation that occur synchronous and with the same amplitude.
Abstract: In the gas explosions simulation practice in non-closed areas there is a common opinion of burning rate increase at turbulization of initial gas mixture stream. The article shows that in conditions of turbulization there is no increase of the burn rate, but of the flame front area. A wording change of pressure rise reason does not lead to a change of the calculation results, but gives the opportunity to look at the problem differently and interpret a physical process correctly. In order to prove it there are results of the vibrational combustion modeling in terms of gas explosion in the cylinder with an opening on the side. The results show that along with the pressure fluctuation there is burning area size fluctuation that occur synchronous and with the same amplitude. The modeling basis is the system of differential equations, that describe the adopted in gas dynamics fundamental conservation laws, the equation of state, written in the so-called Euler’s form. The system is supplemented with flame spread conditions. The system solution is based on the Russian method of the numerical approximation of this system-the large-particle method.

18 citations

Proceedings ArticleDOI
23 Jul 2003
TL;DR: In this article, a 6-segment subscale motor was developed to generate a range of internal environments from which multiple propellants could be characterized for erosive burning, including RSRM, ETM-03, and Castor@ IVA.
Abstract: A 6-segment subscale motor was developed to generate a range of internal environments from which multiple propellants could be characterized for erosive burning. The motor test bed was designed to provide a high Mach number, high mass flux environment. Propellant regression rates were monitored for each segment utilizing ultrasonic measurement techniques. These data were obtained for three propellants RSRM, ETM- 03, and Castor@ IVA, which span two propellant types, PBAN (polybutadiene acrylonitrile) and HTPB (hydroxyl terminated polybutadiene). The characterization of these propellants indicates a remarkably similar erosive burning response to the induced flow environment. Propellant burnrates for each type had a conventional response with respect to pressure up to a bulk flow velocity threshold. Each propellant, however, had a unique threshold at which it would experience an increase in observed propellant burn rate. Above the observed threshold each propellant again demonstrated a similar enhanced burn rate response corresponding to the local flow environment.

18 citations

ReportDOI
01 Jul 1969
TL;DR: In this article, a new theory for extinction by depressurization of AP composite propellants is employed to predict the rate of pressure decrease required to achieve flame-out and rationalize the effects of various composition parameters on the ease of extinguishment.
Abstract: : A new theory for extinction by depressurization of AP composite propellants is employed to predict the rate of pressure decrease required to achieve flame-out and to rationalize the effects of various composition parameters on the ease of extinguishment The research is concentrated mainly on the 'temporary' extinguishment behavior of solid propellants, but a re- ignition theory is also presented Attention is given in this theory to the proper derivation of the nonsteady heat feedback from the gaseous flame zone to the burning surface Included in the model are the essential physical and chemical rate processes of the granular diffusion flame model, as deduced from the steady state burning characteristics A brief study of double-base propellants which indicates that they are considerably easier to extinguish than composite propellants concludes this report A rough model for the burning of double-base propellants is presented which further indicates the importance of the flame structure in determining the extinguishment characteristics of solid propellants

18 citations

Patent
03 Feb 1993
TL;DR: In this paper, an improved high energy impulse rocket is described, which includes a motor case containing propellant composed of individual, free flowing granules of a predetermined shape and unbonded to the motor case.
Abstract: An improved high energy impulse rocket includes a motor case containing propellant composed of individual, free flowing granules of a predetermined shape and unbonded to said motor case. The propellant has a high burning rate of 100 milliseconds or less and generates chamber pressures of up to about 50,000 psi. The rocket motor includes a reentry nozzle open at one end and connected to an exit nozzle, the reentry nozzle forming an annulus to contain the propellant and also forming a barrier to prevent ejection of the propellant during burning. Acceleration of the rocket assists in maintaining the propellant within the motor case, which acceleration may be as high as 20,000 g generating a velocity as high as 10,000 fps. Such a rocket offers unique advantages, especially as a device to punch an opening in a wall structure, the details of which are described as well as other details of the improved and relatively inexpensive impulse rocket.

18 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of flame stretch on the laminar burning velocity of a tube are discussed. And the effect of the Karlovitz stretch factor on the burn rate is discussed.
Abstract: Since the time of Mallard and Le Chatelier there has been a fascination with the problems of flame propagation in tubes. An important goal has been the development of a reliable technique to measure accurately the most basic combustion parameter, the laminar burning velocity. On the one hand a stable, steady-state, flame is necessary to do this, while on the other hand many flames are inherently unstable. These conflicting tendencies have been the source of much creative combustion thinking, not least from Guenoche. The paper attempts to indicate how his work has contributed to our present appreciation of the effects of flame stretch, thermo-diffusion, Darrieus – Landau and Taylor instabilities. Some practical consequences of the effects of these on the burn rate are briefly discussed. Laminar burning velocity and its measurement The purpose of the present paper is to show how Henri Guenoche’s painstaking descriptions and analyses of experimental findings concerning flame propagation in tubes contribute greatly to our current fundamental understanding of combustion. In 1883 Mallard and Le Chatelier [1] showed that the condition of a tube closed at one end with ignition at the other, open, end is probably the one best able to achieve a constant flame speed over a distance sufficient for the measurement of the laminar burning velocity. Thereafter, the flame oscillates, particularly with lean CH4 and H2 and rich hydrocarbon mixtures with air, and then assumes a cellular structure with an enhanced flame speed [2]. Their painstaking studies of the factors that give rise to a regime in which the flame speed is constant led Guenoche and Laffitte [3] to suppress any tendencies to acoustic oscillations by fitting an orifice to vent the burned gas at the open end of the tube, a practice adopted by subsequent workers, to make the vertical tube method a recommended one for measuring burning velocity [4]. Conversely, in the unstable regime forcing oscillations can induce a cellular structure [5]. When the flame attains a constant flame speed through the use of orifice damping its shape hardly changes and hence the effects of flame stretch rate are minimal. In the last decade the quantitative understanding of these effects stretch has advanced considerably and it is now almost mandatory to measure stretch-free values of burning velocity, λ u , together with values of Markstein numbers, Ma, to express the effects of flame stretch rate, in conjunction with the Karlovitz stretch factor, K. Flame stretch can either increase or decrease the burning velocity to a value,

18 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202310
202220
202116
202015
201918
201811