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.

Solid Propellant Burn Rate Modifiers Based on Reactive Nanocomposite Materials

Abstract: : Burn rate modifiers for solid propellants are being developed based on reactive materials prepared by Arrested Reactive Milling. The materials include nanocomposite thermite compositions using aluminum as a fuel and oxides of iron, molybdenum and copper as oxidizers. The materials are characterized using a set of laboratory tests. Conditions for preparation of viable propellant additives are selected based on the reduced ignition temperature and accelerated burn rate achieved for the prepared nanocomposite powders. The compositions addressed in this study are metal rich, minimizing the energetic penalty due to adding these materials to the propellant formulations. Propellants are formulated with selected samples and their mechanical and burn properties are assessed. Processing reactive nanocomposite powders with conventional propellant formulations was successful and mechanical properties were acceptable. Strand combustion experiments and subscale ballistic evaluations showed substantial increase in the burn rate over a broad range of pressures achieved with replacement of only 5 % of aluminum in aluminized propellant with new materials. Furthermore, the slope break in the log of burn rate vs. log of pressure curve is shifted to a higher pressure for the formulation with the nanocomposite modifier. This shift is expected to be advantageous for the design of rocket motors operating at pressures higher than those used for the current high performance aluminized HTPB propellants.

Optical control method for solid fuel rocket burn rate

Abstract: A solid fuel rocket burn rate control method wherein grain preheating energy is supplied to the grain region just ahead of the regressing burn face by optical conductors such as fiber optic filaments that are buried in the grain and dispersed across the grain cross section. The optical conductors receive optical energy from one of several types of electrical-to-optical energy transducers such as a semiconductor laser or an incandescent source; the optical conductors promote coning burn action at the burn face of the rocket and allow control of the burn rate by electrically modified optical signals.

Solid propellant ignition by convective heating.

Abstract: : The objective of the study was to determine the effects of gas flow characteristics on solid propellant ignition behavior under convective heating Ignition tests of three composite propellants were conducted in a hot-gas tunnel designed for convective heating experiments Effects of gas velocity, test chamber configuration, and approach surface material on ignition were observed It is concluded that ignition is initiated in the gas phase and is influenced by the local temperature and the local concentration of oxidizer decomposition products from upstream portions of the propellant surface Either temperature or oxidizer concentration may control the time of ignition When oxidizer concentration is controlling, the test configuration and gas velocity are important parameters When temperature is controlling, ignition time can be correlated with heating rate alone However, long propellant samples must be used to obtain meaningful data Ignition times measured with long propellant samples are considerably lower than those measured with small samples (Author)