Download or read book Combustion of Porous Energetic Materials in the Merged flame Regime written by and published by . This book was released on 1996 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The structure and burning rate of an unconfined deflagration propagating through a porous energetic material is analyzed in the limit of merged condensed and gas-phase reaction zones. A global two-step reaction mechanism, applicable to certain types of degraded nitramine propellants and consisting of sequential condensed and gaseous steps, is postulated. Taking into account important effects due to multiphase flow and exploiting the limit of large activation energies, a theoretical analysis based on activation energy asymptotics leads to explicit formulas for the deflagration velocity in a specifically identified regime that is consistent with the merged-flame assumption. The results clearly indicate the influences of two-phase flow and the multiphase, multi-step chemistry on the deflagration structure and the burning rate, and define conditions that support the intrusion of the primary gas flame into the two-phase condensed decomposition region at the propellant surface.

Download or read book Eigenvalue Analysis and Calculations for the Deflagration of Porous Energetic Materials in the Merged flame Regime written by and published by . This book was released on 1996 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analytical and numerical calculations of the structure and burning rate of a deflagrating porous energetic material are presented for the limiting case of merged condensed and gas-phase reaction zones. The reaction scheme is modeled by a global two-step mechanism, applicable to certain types of degraded nitramine propellants and consisting of sequential condensed and gaseous steps. Taking into account important effects due to multiphase flow and exploiting the limit of large activation energies, a theoretical analysis may be developed based on activation-energy asymptotics. For steady, planar deflagration, this leads to an eigenvalue problem for the inner reaction-zone, the solution of which determines the burning rate. Numerical solutions give a reasonably complete description of the dependence of the structure and burning rate on the various parameters in the problem, and show excellent agreement with analytical results that are obtained in a more limited parameter regime in which most of the heat release is produced by the condensed-phase reaction and the porosity of the solid is small. These calculations indicate the significant influences of two-phase flow and the multiphase, multi-step chemistry on the deflagration structure and the burning rate, and thus serve to define an important parameter regime that supports the intrusion of the primary gas flame into the two-phase condensed decomposition region at the propellant surface.

Download or read book Analyses of Combustion Processes in Porous Energetic Materials written by Alexander M. Telengator and published by . This book was released on 2000 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Eigen value Calculations for Porous Energetic Material Deflagration in the Merged flame Regime written by Nenad Ilincic and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book AIAA Aerospace Sciences Meeting and Exhibit 42nd written by and published by . This book was released on 2004 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Solid Propellant Chemistry Combustion and Motor Interior Ballistics written by Vigor Yang and published by AIAA (American Institute of Aeronautics & Astronautics). This book was released on 2000 with total page 1044 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume brings together the world's most highly regarded scientists in the field of solid rocket propulsion. Thirty-nine papers present in-depth coverage on a wide range of topics including: advanced materials and nontraditional formulations; the chemical aspects of organic and inorganic components in relation to decomposition mechanisms, kinetics, combustion, and modeling; safety issues, hazards and explosive characteristics; and experimental and computational interior ballistics research, including chemical information and the physics of the complex flowfield.

Download or read book MILD Combustion Modelling Challenges Experimental Configurations and Diagnostic Tools written by Alessandro Parente and published by Frontiers Media SA. This book was released on 2021-11-26 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combustion of Two Phase Reactive Media written by L. P. Yarin and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion of Two-Phase Reactive Media addresses the complex phenomena involved in the burning of solid and liquid fuels. In fact, the multiplicity of phenomena characteristic of combustion of two-phase media determine the contents. The three parts deal with: the dynamics of a single particle; combustion wave propagation in two-phase reactive media; and thermal regimes of combustion reactors. The book generalizes the results of numerous investigations into the ignition and combustion of solid particles, droplets and bubbles, combustion wave propagation in heterogeneous reactive media, the stability of combustion of two-phase media, as well as the thermal regimes of high-temperature combustion reactors. It merges findings from the authors’ investigations into problems of two-phase flows and material from graduate-level courses they teach at Technion-Israel Institute of Technology.

Download or read book Energetic Materials written by Manoj K. Shukla and published by Springer. This book was released on 2017-10-09 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a comprehensive account of energetic materials, including their synthesis, computational modeling, applications, associated degradation mechanisms, environmental consequences and fate and transport. This multi-author contributed volume describes how armed forces around the world are moving their attention from legacy explosive compounds, which are heat and shock sensitive (thus posing greater challenges in terms of handling and storage), to the insensitive munitions compounds/formulations such as insensitive munitions explosive (IMX) and the Picatinny Arsenal Explosive (PAX) series of compounds. The description of energetic materials focuses on explosives, pyrotechnic compositions, and propellants. The contributors go on to explain how modern generation energetic compounds must be insensitive to shock and heat but at the same time yield more energy upon explosion. Nanoinspired and/or co-crystallized energetic materials offer another route to generate next-generation energetic materials, and this authoritative book bridges a large gap in the literature by providing a comprehensive analysis of these compounds. Additionally, it includes a valuable overview of energetic materials, a detailed discussion of recent advances on future energetic compounds, nanotechnology in energetic materials, environmental contamination and toxicity, assessment of munitions lethality, the application quantitative structure–activity relationship (QSAR) in design of energetics and the fate and transport of munition compounds in the environment.

Download or read book Combustion Aspects of the Reapplication of Energetic Materials as Fuels as a Viable Demil Technology written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Sublimation and Pyrolysis on Quasi Steady Deflagrations in Confined Porous Energetic Materials written by and published by . This book was released on 2001 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deflagrations in porous energetic materials under confinement are generally characterized by a relatively rapid increase in the burning rate as the pressure difference, or overpressure, in the burned-gas region relative to that deep within the pores of the unburned solid increases. Specifically, there appears to be a range of overpressures in which the sensitivity, or slope, of the propagation speed as a function of overpressure transitions from relatively small to large values. This effect has been qualitatively attributed to the fact that a sufficient overpressure reverses the gas flow and thus allows the burned gas to permeate, and therefore preheat, the porous material. However, quantitative descriptions of both the process itself and the corresponding burning-rate dependencies have only recently been achieved. The present work reflects a further refinement in this analytical description in that the melt layer, which underlies several previous studies and is likely to exist only at modest overpressures, is replaced by sublimation and pyrolysis at the material surface, followed by an attached gas flame that converts the unburned gaseous reactants to final products. As a result, gaseous reactants as well as products now permeate the porous solid, thereby affecting the propagation speed significantly and modifying both the combustion-wave structure and the transition to convection-enhanced burning.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1996-09 with total page 1244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 38th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit 02 4150 02 4199 written by and published by . This book was released on 2002 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 32nd AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit written by and published by . This book was released on 1996 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stability of Quasi Steady Deflagrations in Confined Porous Energetic Materials written by and published by . This book was released on 2000 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Previous analyses have shown that unconfined deflagrations propagating through both porous and nonporous energetic materials can exhibit a thermal/diffusive instability that corresponds to the onset of various oscillatory modes of combustion. For porous materials, two-phase-flow effects, associated with the motion of the gas products relative to the condensed material, play a significant role that can shift stability boundaries with respect to those associated with the nonporous problem. In the present work, additional significant effects are shown to be associated with confinement, which produces an overpressure in the burned-gas region that leads to reversal of the gas flow and hence partial permeation of the hot gases into the unburned porous material. This results in a superadiabatic effect that increases the combustion temperature and, consequently, the burning rate. Under the assumption of gas phase quasi-steadiness, an asymptotic model is presented that facilitates a perturbation analysis of both the basic solution, corresponding to a steadily propagating planar combustion wave, and its stability. The neutral stability boundaries collapse to the previous results in the absence of confinement, but different trends arising from the presence of the gas-permeation layer are predicted for the confined problem. Whereas two-phase-flow effects are generally destabilizing in the unconfined geometry, the effects of increasing overpressure and hence combustion temperature associated with confinement are shown to be generally stabilizing with respect to thermal/diffusive instability, analogous to the effects of decreasing heat losses on combustion temperature and stability in single-phase deflagrations.

Download or read book Ignition Analyses of Porous Energetic Materials written by Alexander M. Telengator and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: