Detonation

Abstract: A detailed description of the equations and computer program for computations involving chemical equilibria in complex systems is given. A free-energy minimization technique is used. The program permits calculations such as (1) chemical equilibrium for assigned thermodynamic states (T,P), (H,P), (S,P), (T,V), (U,V), or (S,V), (2) theoretical rocket performance for both equilibrium and frozen compositions during expansion, (3) incident and reflected shock properties, and (4) Chapman-Jouguet detonation properties. The program considers condensed species as well as gaseous species.

Abstract: Review of Chemical Thermodynamics. Review of Chemical Kinetics. Conservation Equations for Multi--Component Reacting Systems. Rankine--Hugoniot Relations of Detonation and Deflagration Waves of Premixed Gases. Premixed Laminar Flames. Diffusion Flames and Combustion of a Single Liquid Fuel Droplet. Turbulent Flames. Turbulent Reacting Flows with Premixed Reactants. Chemically Reacting Boundary--Layer Flows. Ignition. Appendix. Index.

Abstract: The major uncertainties involved in the Chandrasekhar mass models for Type Ia supernovae (SNe Ia) are related to the companion star of their accreting white dwarf progenitor (which determines the accretion rate and consequently the carbon ignition density) and the flame speed after the carbon ignition. We calculate explosive nucleosynthesis in relatively slow deflagrations with a variety of deflagration speeds and ignition densities to put new constraints on the above key quantities. The abundance of the Fe group, in particular of neutron-rich species like 48Ca,50Ti,54Cr,54,58Fe, and 58Ni, is highly sensitive to the electron captures taking place in the central layers. The yields obtained from such a slow central deflagration, and from a fast deflagration or delayed detonation in the outer layers, are combined and put to comparison with solar isotopic abundances. To avoid excessively large ratios of 54Cr/56Fe and 50Ti/56Fe, the central density of the average white dwarf progenitor at ignition should be as low as 2 ? 109 g cm-3. To avoid the overproduction of 58Ni and 54Fe, either the flame speed should not exceed a few percent of the sound speed in the central low Ye layers or the metallicity of the average progenitors has to be lower than solar. Such low central densities can be realized by a rapid accretion as fast as -->img1.gif 1 ? 10-7 M? yr-1. In order to reproduce the solar abundance of 48Ca, one also needs progenitor systems that undergo ignition at higher densities. Even the smallest laminar flame speeds after the low-density ignitions would not produce sufficient amount of this isotope. We also found that the total amount of 56Ni, the Si-Ca/Fe ratio, and the abundance of some elements like Mn and Cr (originating from incomplete Si burning), depend on the density of the deflagration-detonation transition in delayed detonations. Our nucleosynthesis results favor transition densities slightly below 2.2 ? 107 g cm-3.

Abstract: Part 1 Volume 1: equations of mechanics of heterogeneous continuous media mechanics of processes near dispersed particles drops and bubbles wave dynamics of shocks and detonations in condensed media with phase transitions dynamics of two-velocity flows of disperse media (gas-particle suspensions) gas and wave dynamics of combustion and detonation of gas particle suspensions and powders. Part 2 Volume 2: wave dynamics of bubbly liquids hydrodynamics and thermodynamics of stationary one-dimensional gas-liquid and vapor-liquid flows in channels theory of inertia-free and percolation flows of heterogeneous media.