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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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23 Oct 2006
TL;DR: In this article, the authors measured the laminar deflagration rate of LX-17 (92.5 wt% TATB, 7.5 Wt% Kel-F 800) at high pressure and temperature in a strand burner, thereby obtaining reaction rate data for prediction of thermal explosion violence.
Abstract: We measure the laminar deflagration rate of LX-17 (92.5 wt% TATB, 7.5 wt% Kel-F 800) at high pressure and temperature in a strand burner, thereby obtaining reaction rate data for prediction of thermal explosion violence. Simultaneous measurements of flame front time-of-arrival and temporal pressure history allow for the direct calculation of deflagration rate as a function of pressure. Additionally, deflagrating surface areas are calculated in order to provide quantitative insight into the dynamic surface structure during deflagration and its relationship to explosion violence. Deflagration rate data show that LX-17 burns in a smooth fashion at ambient temperature and is represented by the burn rate equation B = 0.2P{sup 0.9}. At 225 C, deflagration is more rapid and erratic. Dynamic deflagrating surface area calculations show that ambient temperature LX-17 deflagrating surface areas remain near unity over the pressure range studied.
Proceedings ArticleDOI
30 Jul 2012
TL;DR: In this paper, an active thrust modulation system of solid propellant motor was proposed and verified experimentally, where an appropriate selection of throat diameter presents two combustion modes in the same motor geometry.
Abstract: An active thrust modulation system of solid propellant motor was proposed and verified experimentally. Candidate propellants have a self-quenched property at intermediate pressure, while they can deflagrate at lower and higher pressure. Appropriate selection of throat diameter presents two combustion modes in the same motor geometry. Propellant with 73 % oxidizer content had demonstrated successfully two-mode active thrust modulation. The propellant with 75 % oxidizer content was examined. While the specific impulse showed little difference from 73 % AP propellant, the thrust density of 75 % AP propellant motor became high. The higher burning rate and the narrowed self-quenched pressure range made the thrust modulation a little difficult. An effect of a negative catalyst LiF was discussed. Slight addition of the catalyst had an effect to widen the intermediate self-quenched pressure range, but little effect to suppress the pressure amplitude in regulating the low mode pressure. More motor combustion tests are needed to confirm its availability.
01 Jul 1978
TL;DR: In this article, a transient ballistics and combustion model is derived to represent the closed vessel experiment that is widely used to characterize the high pressure burning rates of solid propellants, and the model is applied to explain why burning rates deduced from a closed vessel are in basic agreement with those measured from an equilibrium strand burner in the case of homogeneous propellants.
Abstract: A transient ballistics and combustion model is derived to represent the closed vessel experiment that is widely used to characterize the high pressure burning rates of solid propellants. The model is applied to explain why burning rates deduced from the closed vessel are in basic agreement with those measured from an equilibrium strand burner in the case of homogeneous propellants, but differ significantly in the case of nitramine composite propellants. Thermal profile time lag effects become small at high pressure because the burning rates become high. However, the development of the burning surface structure of those nitramine propellants which exhibit shifts in pressure exponent causes the mass burning rate to lag and then exceed the equilibrium value. It is necessary to consider this mechanism in applications dealing with high pressures and pressurization rates.
Journal ArticleDOI
TL;DR: In this article , a new model based on STANAG 4367 was developed, which describes the burning velocity with a depth-dependent Vieille's law and can also take into account a multivariate size distribution of the propellant grains and depth and pressure-dependent thermodynamic properties.
Abstract: Deterred gun propellants with multivariate size distribution are widely used in small-calibre guns. While the surface treatment is used to increase the progressivity of the propellant and therefore the performance, the size distribution is due to variations in the production process. When standard models or methods for the burn rate measurement, e. g. according to STANAG 4115, are used to determine burning rates and burn rate parameters, they generally suffer from poor generalizability and are of little use for the simulation of the burning behaviour inside a gun. Therefore, a new model based on STANAG 4367 was developed, that addresses these issues. It describes the burning velocity with a depth-dependent Vieille's law and can also take into account a multivariate size distribution of the propellant grains and depth and pressure-dependent thermodynamic properties. The model is used to define an objective function to fit simulated dynamic vivacities to experimental data and thus determine burn rate coefficients in a modified Vieille's law. The method was validated by using synthetic dynamic vivacities as input data for the fitting procedure. To test the model, closed vessel experiments were conducted with a deterred double-base propellant. It is shown that the model gives an excellent description of the experimental data with reasonable burn rate coefficients and does not suffer from the drawbacks of other methods.
Journal ArticleDOI
TL;DR: In this paper , the authors derived and established the form function of a complex geometry stick propellant and analyzed the influence of cutting parameters on its form function, and they found that the notch had a significant effect on the combustion characteristics of the propellant.
Abstract: To study the form function and combustion characteristics of partially-cut stick propellants, this paper derived and established the form function of this complex geometry propellant and analyzed the influence of cutting parameters on the form function. The analysis showed that partially-cut stick propellants retain the high progressive combustion of multi-aperture granular propellant, which is proportional to the distance between the notch and inversely proportional to the width of the notch. Based on this, partially-cut stick propellants with different notches were prepared, and closed vessel tests were conducted. The experimental results showed that the notch had a significant effect on the combustion characteristics of the propellant. When there were notches, the wider the notch, the faster the pressure rise. The pressure in the closed vessel for stick propellants without notches rose the fastest. The burning rate of non-notched or narrow-notched fluctuated, while the burning rate of wide-notched was stable. The dynamic vivacity data showed that the wider the notch, the more stable the change of the burning surface, and the combustion characteristic was closer to the granular propellant. Based on the analysis of form function and combustion characteristics, it is recommended that the notch width be 1 mm and the distance between notches on the same side should be the length of a granular propellant for the double-base homogeneous 19-perforated propellant studied in this paper.

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