Ignition and Wave Processes in Combustion of Solids

Preface...1 Acknowledgements...7 Contents...7 Introduction...9 References...23 Chapter I. The theory of a local ignition...28 1. On the theory of a local thermal explosion...28 2. Non-stationary ignition of a hot spot...34 3. Initiation of a hydrogen-air flame with a hot spot.Verification of the theory...40 Conclusions to Chapter I...54 References...55 Chapter II. The wave theory of ignition...57 1. Ignition of the condensed substances with heat losses from the side surface...58 2. Ignition of a condensed substance with a constant heat flux released in two competing exothermic reactions...67 3. The features of ignition of the condensed systems interacting through a layer of a refractory product with an energy flux ...77 4. Regularities of ignition of the condensed systems with a heated surface according to the parabolic law of chemical interaction...85 5. Regularities of ignition of porous bodies under conditions of a counter non-stationary filtration of gas...96 6. Ignition of porous substances with the filterable gas. Cocurrent non-stationary filtration...113 Conclusions to Chapter II...128 References...130 Chapter III. The convective-conductive theory of combustion of condensed substances...133 1. Convective combustion of "gasless" systems...134 2. Convective heat and mass transfer in the processes of "gasless" combustion...148 3. The features of combustion of the mixes Ti+0.5C and Ti+C of bulk density in a cocurrent flow of inert gas...161 4. Influence of humidity on the features of combustion of powder and granulated Ti+0.5C mixes...171 5. Dependence of combustion velocity on the sample size in nonactivated and mechanically activated Ni +Al systems...178 6. Combustion of cylindrical Ti + 0.5C compacts: influence of mechanical activation, thermovacuum processing, and ambient pressure...184 References...188 Conclusions to Chapter III...193 Chapter 4. Theory of ignition of gas suspensions...194 1. Analytical method of calculation of critical conditions of a local ignition of gas suspensions of solid particles...196 2. Analysis of critical conditions of ignition of gas suspension with a heated body at pulse energy supply...205 3. Mathematical modeling of the process of ignition of gas suspension of solid particles in a mix oxidizer - combustible gas (a local ignition)...221 4. Thermal ignition of hybrid gas suspensions in the presence of natural gas and chemically active additives...233 References...239 Conclusions to Chapter IV...242 Chapter V. Ignition, combustion and passivation of nanopowders...243 1. Ignition of pyrophoric powders: An entry-level model...247 2. Temporal characteristics of ignition and combustion of iron nanoparticles in the air...254 3. Synthesis and characterization of passivated iron nanoparticles...263 4. Passivation of iron nanoparticles at subzero temperatures...268 Conclusions to Chapter V...276 References...277 Conclusions...282