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 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 Over pressure Effects on the Stability of Deflagrations on Confined Porous Energetic Materials written by Alexander M. Telengator and published by . This book was released on 2001 with total page 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 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 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 Analysis of a Two temperature Model of Deflagrations in Confined Porous Energetic Materials written by Stephen B. Margolis and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Intrusive and Nonintrusive Deflagrations in Confined Porous Energetic Materials written by Stephen B. Margolis and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structure and Stability of Deflagrations in Porous Energetic Materials written by and published by . This book was released on 1999 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical two-phase-flow analyses have recently been developed to describe the structure and stability of multi-phase deflagrations in porous energetic materials, in both confined and unconfined geometries. The results of these studies are reviewed, with an emphasis on the fundamental differences that emerge with respect to the two types of geometries. In particular, pressure gradients are usually negligible in unconfined systems, whereas the confined problem is generally characterized by a significant gas-phase pressure difference, or overpressure, between the burned and unburned regions. The latter leads to a strong convective influence on the burning rate arising from the pressure-driven permeation of hot gases into the solid/gas region and the consequent preheating of the unburned material. It is also shown how asymptotic models that are suitable for analyzing stability may be derived based on the largeness of an overall activation-energy parameter. From an analysis of such models, it is shown that the effects of porosity and two-phase flow are generally destabilizing, suggesting that degraded propellants, which exhibit greater porosity than their pristine counterparts, may be more readily subject to combustion instability and nonsteady deflagration.

Download or read book Effects of Two phase Flow on the Deflagration of Porous Energetic Materials written by Stephen B. Margolis and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Two phase Flow on the Deflagration of Porous Energetic Materials written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Rocket Propulsion written by Luigi T. De Luca and published by Springer. This book was released on 2016-08-19 with total page 1069 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developed and expanded from the work presented at the New Energetic Materials and Propulsion Techniques for Space Exploration workshop in June 2014, this book contains new scientific results, up-to-date reviews, and inspiring perspectives in a number of areas related to the energetic aspects of chemical rocket propulsion. This collection covers the entire life of energetic materials from their conceptual formulation to practical manufacturing; it includes coverage of theoretical and experimental ballistics, performance properties, as well as laboratory-scale and full system-scale, handling, hazards, environment, ageing, and disposal. Chemical Rocket Propulsion is a unique work, where a selection of accomplished experts from the pioneering era of space propulsion and current technologists from the most advanced international laboratories discuss the future of chemical rocket propulsion for access to, and exploration of, space. It will be of interest to both postgraduate and final-year undergraduate students in aerospace engineering, and practicing aeronautical engineers and designers, especially those with an interest in propulsion, as well as researchers in energetic materials.

Download or read book Combustion of Energetic Materials written by Kenneth K. Kuo and published by Begell House Publishers. This book was released on 2002 with total page 1114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited book contains state-of-the-art information associated with energetic material combustion. There are twelve topical areas, including: Reaction Kinetics of Energetic Materials (Solid, Liquid, and Gel Propellants); Recycling of Energetic Materials; Combustion Performance of Hybrid and Solid Rocket Motors; Ignition and Combustion of Energetic Materials; Energetic Material Defects and Rocket Engine Flowfields; Metal Combustion; Pyrolysis and Combustion Processes of New Ingredients and Applications; Theoretical Modeling and Numerical Simulation of Combustion Processes of Energetic Materials; Combustion Diagnostic Techniques; Propellant and Rocket Motor Stability; Commercial Applications of Energetic Materials (Airbags, Gas Generators, etc.); and Thermal Insulation and Ablation Processes.

Download or read book Solid Propellant Chemistry Combustion and Motor Interior Ballistics 1999 written by Vigor Yang and published by AIAA. This book was released on 2000 with total page 1038 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Decomposition Combustion and Detonation Chemistry of Energetic Materials written by Thomas B. Brill and published by . This book was released on 1996 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energetic materials are distinguished from other materials primarily by the fact that rapid, exothermic reactions can be induced with the release of gaseous products. This complex phenomenon cuts across many boundaries of chemistry (synthesis, kinetics, thermodynamics, spectroscopy, quantum and molecular dynamics calculations, etc.) and engineering physics (shock and detonation waves, hydrodynamics, fracture and solid mechanics, defects, etc.). This volume offers the latest chemistry advancements in understanding the complex dynamic processes in these materials in the condensed phase. The focus is on fundamental research into the rates and pathways of rapid exothermic reactions, product specification, diagnostic methods, molecular processes of energy transfer, and molecular processes at extreme pressure and temperature. Many novel materials are discussed.

Download or read book Fundamentals of Rocket Propulsion written by DP Mishra and published by CRC Press. This book was released on 2017-07-20 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book follows a unified approach to present the basic principles of rocket propulsion in concise and lucid form. This textbook comprises of ten chapters ranging from brief introduction and elements of rocket propulsion, aerothermodynamics to solid, liquid and hybrid propellant rocket engines with chapter on electrical propulsion. Worked out examples are also provided at the end of chapter for understanding uncertainty analysis. This book is designed and developed as an introductory text on the fundamental aspects of rocket propulsion for both undergraduate and graduate students. It is also aimed towards practicing engineers in the field of space engineering. This comprehensive guide also provides adequate problems for audience to understand intricate aspects of rocket propulsion enabling them to design and develop rocket engines for peaceful purposes.

Download or read book Nano Energetic Materials written by Shantanu Bhattacharya and published by Springer. This book was released on 2018-11-09 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest research on the area of nano-energetic materials, their synthesis, fabrication, patterning, application and integration with various MEMS systems and platforms. Keeping in mind the applications for this field in aerospace and defense sectors, the articles in this volume contain contributions by leading researchers in the field, who discuss the current challenges and future perspectives. This volume will be of use to researchers working on various applications of high-energy research.