Experiments were carried out in FY04 on detonation wave structure, detonation wave diffraction, and the fracture of thin-walled tubes by detonation waves. Computations were performed on detonation wave propagation and the elastic response of tubes to detonation loading. One new effort was initiated on the diffraction of detonation waves, and the other activities were a continuation of previous ...

A numerical simulation study was performed to examine the post-detonation reaction processes produced by detonation of a 12 mm diameter hemispherical pentaerythritol tetranitrate (PETN) explosive charge. The simulations used finite rate detailed chemical model consisting 59 species and 368 reactions capture including air dissociation from Mach 19+ shock waves that initially break out PETN charg...

This study describes a methodology and gives an example of a simplified analysis to determine the steady propagation speed of a projectile fired into a gaseous mixture of fuel and oxidizer. For tractability, the steady supersonic flow of an inviscid calorically perfect ideal reacting gas with high activation energy over a symmetric double wedge, unconfined by a cowl, is considered. A search of ...

Research at the Explosion Dynamics Laboratories at Caltech over the past three years under an ONR contract has examined many issues critical to Pulse Detonation Engine (PDE) development. These include: fundamental and applied studies of detonation initiation; detonation cell width measurements to characterize fuels, including JP10; visualization of the reaction zone structure of propagating det...

One of the basic equations to analyze the detonation of high explosives is the equation of state of the detonation products. Due to the very high pressure of the product, the direct measurement of the thermodynamic variables such as pressure or temperature is not possible. In this research, the parameters of BKW and HOM equations of state of detonation products are determined via experimental m...

A study of detonations in high molecular weight hydrocarbon fuels was performed in two GALCIT facilities: the 280 mm gaseous detonation tube (GDT) and a 1180 liter vessel (HYJET) with jet initiation capability. In the GDT, detonation pressure, wave speed and cell width measurements were made in hexane-oxygen-nitrogen mixtures with and without the addition of lower molecular weight fuels. Stoich...

an optical system has been redesigned and used to measure detonation velocity as a function of condensed explosive density for rdx, hmx, petn. these measurements are then used to determine and fine tune parameters appearing in the bkw (beker-kistiakowsky-wilson) equation of state for gases at extremely high pressures. steady state form of conservation equations along with the bkw state equation...

An auto-ignition detonation phenomenon can be initiated by a wedge confined in a channel. A new, self-sustaining, normal detonation wave engine concept is proposed. The detonation processes were numerically modeled with a simplified two-dimensional wedged channel flow that was deemed to emulate a real three-dimensional configuration. The results showed that within certain ranges of incoming flo...

Research carried out from 2003-2005 at the Explosion Dynamics Laboratories at Caltech under an ONR contract has examined many issues critical to Pulse Detonation Engine (PDE) development. These include: detonation structure imaging using OH PLIF; a narrow channel facility for examining regular and irregular detonations; detonation diffraction; mechanism of soot track generation; fundamental and...

A gaseous detonation wave that emerges from a channel into an unconfined space is known as diffraction. If the dimension of exit below some critical value, incident fails to re-initiate (i.e., transmit self-sustained propagating) in area. In previous study, Xu et al. [“The role cellular instability on tube diameter problem for unstable detonations,” Proc. Combust. Inst. 37(3), 3545–3533 (2019)]...