In the event of a single, low-yield nuclear detonation in a major urban area, rapidly providing adequate shelter to affected populations could save 10 000– 100 000 individuals from a fatal exposure to fallout radiation. However, poorly sheltered individuals may remain at risk. Current guidance and prior studies are not consistent as to the timing and conditions under which poorly sheltered indi...

We consider a simplified model of an unconfined one-dimensional detonation problem, giving a brief survey of the history of the problem and of its numerical solution. This problem with its mathematical features is typical of those solved commercially by ICI plc, and the specific values used for the chemical constants in the example are typical of those of interest. Unfortunately, not all obviou...

The isomeric di-1,2,3,4-tetrazine tetraoxides DTTO and iso-DTTO have aroused considerable interest in recent years as potential energetic compounds, due to their predicted high densities and heats of formation and superior detonation properties. While neither has yet been synthesized, it has been suggested that the N→O linkages on alternate nitrogens will have a stabilizing effect. In the prese...

The aim of the work performed in the current contract is to assess the accuracy of potential modelling techniques applied to the formation of Deflagration to Detonation (DDT) kernels in mixtures of hydrocarbons with air. The application area is of direct relevance to the transition to detonation in pulsed detonation engines featuring premixed gases. The latter technology is currently pursued at...

Context. A promising model for normal Type Ia supernova (SN Ia) explosions are delayed detonations of Chandrasekhar-mass white dwarfs, in which the burning starts out as a subsonic deflagration and turns at a later phase of the explosion into a supersonic detonation. The mechanism of the underlying deflagration-to-detonation transition (DDT) is unknown in detail, but necessary conditions have b...

It is possible to objectively determine whether a detona tion can propagate in a given geometry (volume shape and size, obstacle configuration, degree of confinement) for a given mixture composition (concentrations of hydrogen, air and steam); this is done by conservatively equating the detonation propaga tion criteria with the criteria for transition from deflagration to detonation. This paper...

Numerical simulations can be the key to the thorough understanding of the multi-dimensional nature of transient detonation waves. But the accurate approximation of realistic detonations is extremely demanding, because a wide range of different scales need to be resolved. This paper describes an efficient simulation strategy based on a generic implementation of a blockstructured dynamically adap...

We speculate that the universe is filled with stars composed of electromagnetic and dilaton fields. We calculate soliton-like solutions of these fields and show that their energy can be converted into a relativistic plasma in an explosive way whioch produces strong gamma-ray bursts observed in the universe. The conversion proceeds as in classical detonation theory by a relativistic self-similar...

Experimental images of propagating detonation waves provide lead shock velocity measurements through the cell cycle. We examine the issue of local decoupling of the shock and reaction front using these data. In highly unstable mixtures with high reduced activation energy, experimental images and analysis suggest that local decoupling occurs at the end of the cell cycle. Regions of high fluoresc...