Impulse generation with gaseous detonation requires conversion of chemical energy into mechanical energy. Because of the poor performance of straight detonation tubes compared to conventional propulsion systems and the success of using nozzles on rocket engines, the effect of nozzles on detonation tubes is being investigated. The first experimental investigation measuring impulse by gaseous det...

A nonlinear integral-differential equation describing the cellular front of an overdriven detonation is obtained by an analysis carried out in the neighborhood of the instability threshold. The analysis reveals both an unusual mean streaming motion, resulting from the rotational part of the oscillatory flow, and pressure bursts generated by the crossover of cusps representative of Mach stems pr...

T o address the hazards to civilians, recent landmine systems have incorporated command detonation by remote operator and self-destruct capabilities (see the “Landmines through the Ages” sidebar). However, these additions didn’t let the mines adaptively counter breach attempts and might have actually increased the need to monitor mine location to allow command detonation. Nor did they allow ope...

Two-dimensional reactive Navier-Stokes equations are solved using a simple implicit Beam-Warming finite difference scheme. Comparisons of the detonation wave solutions of reactive Euler equations and reactive Navier-Stokes equations show that physical diffusion is important at high resolution when the numerical diffusion becomes negligible. Hence, for accurate detonation wave solutions it is ne...

A nuclear detonation in a US city would have profound psychological, social, and behavioral effects. This article reviews the scientific literature on human responses to radiation incidents and disasters in general, and examines potential behavioral health care provider (BHCP) contributions in the hours and days after a nuclear detonation. In the area directly affected by the blast, the immedia...

Time-dependent, two-dimensional, numerical simulations of a transmitted detonation show reignition occuring by one of two mechanisms. The first mechanism involves the collision of triple points as they expand along a decaying shock front. In the second mechanism ignition results from the coalescence of a number of small, relatively high pressure regions left over from the decay of weakened tran...

The dynamics of one-dimensional, overdriven, hydrogen-air detonations predicted in the inviscid limit as well as with the inclusion of mass, momentum, and energy diffusion were investigated. A series of shock-fitted calculations was performed in which the overdrive was varied in the inviscid limit. The 0.97 MHz frequency of oscillation predicted for a f = 1.1 overdriven detonation agrees well w...

Imploding toroidal detonation waves were used to initiate detonations in propane–air and ethylene–air mixtures inside of a tube. The imploding wave was generated by an initiator consisting of an array of channels filled with acetylene–oxygen gas and ignited with a single spark. The initiator was designed as a low-drag initiator tube for use with pulse detonation engines. To detonate hydrocarbon...

Mechanisms underlying detonation initiation in 1-D and 2-D configurations are explored computationally. The strong state-sensitivity of the underlying chemical kinetics causes the reaction zones to be exceedingly thin, and accuracy of solution demands that the computational scheme provide the necessary resolution with economy. This is achieved by a technique that employs overlapping grids and b...