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 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 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 On the Stability of Deflagration Through a Porous Energetic Material 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 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 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 37th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit written by and published by . This book was released on 2001 with total page 620 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 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 Investigation on Deflagration to Detonation Transition in Porous Energetic Materials Final Report written by 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 A Singular Perturbation Analysis of the Burning Rate Eigenvalue for a Two Temperature Model of Deflagrations in Confined Porous Energetic Materials written by and published by . This book was released on 2000 with total page 5 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 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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 542 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 Chemical Abstracts written by and published by . This book was released on 2002 with total page 2626 pages. Available in PDF, EPUB and Kindle. Book excerpt: