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.

Combustion response to compositional fluctuations

Abstract: A mechanism involving compositional fluctuations at certain frequencies is examined by which the heterogeneity of a composite solid propellant may contribute directly to the combustion response function of combustion instability theory. A combustion model appropriate to ammonium perchlorate (AP) is used to derive the combustion response to compositional fluctuations, and the properties of the combustion response are discussed in terms of the theoretical results obtained. The concentration exponent, i.e., the dependence of the burn rate on AP concentration, is found to be a signficant combustion parameter and to have a tremendous range of variability. It is suggested that the combustion response to compositional fluctuations may be a dominating factor in driving combustion instability.

Ultrasonic Measurement of the Regression Rate of the Melting Interface in Burning Metal Rods

Abstract: Results of tests in which metallic rods are burned in oxygen-enriched atmospheres often include the regression rate of the melting interface for the burning test specimen. This regression rate is used as an indication of a metallic materials' relative flammability when different metallic materials burn at the same test pressure and as an indication of a metallic materials' general ability to sustain burning under the test conditions. Most past methods for determining this regression rate have been based on visual interrogation which is costly, time consuming and often inaccurate. Inaccuracies typically result due to the specific method used (scale factors, optics, visualisation techniques, etc.), and often a limited access time with which to view the combustion event, or obscuration of the burning by condensed-phase products. An ultrasonic transducer has been fabricated to directly measure the regression rate of the melting interface established during the burning of metal rods, thus eliminating many of these problems. The transducer is described, typical results for an iron rod burning in pure oxygen are given along with a comparison of these results with regression rates obtained from visual interrogation. Excellent agreement is obtained between the regression rate obtained from the new ultrasonic transducer and regression rates obtained visually, thus demonstrating the transducer's usefulness.

An experimental study on the ignition and combustion characteristics of pasty propellant

Abstract: The ignition and combustion characteristics of pasty propellant are important parameters for the motor design. An experimental study on the pasty propellant named PEPA/AP was carried out. The results show that the autoignition temperature of this propellant is about 150℃, so it is easy to ignite. As the chamber pressure is greater than 0.6MPa, the critical combustion diameter is less than 1mm. As the test motor is in operation, its propellant burning rate accords with the static burning rate. It is predicted that the propellant will be suitable for multiplestart motor.

An experimental study of composite propellant burning thermal wave in the presence of crossflow

Abstract: An experimental research of the composite propellant thermal wave structure under cross flow conditions was performed by means of microthermocouple technique. The propellant surface temperature and the heat feedback from flame were measured. The reaction time of reactants in the gas phase is obtained. The results show that the erosive burning is complex phenomenon due to the interaction of combustion gases crossflow and the reactants which in turn affects the flame structure thus affecting the heat flux from flame to the burning surface. The surface temperature is found to be a parameter of minor importance for the propellant burning rate under crossflow conditions.