Pulse detonation propulsion : challenges, current status, and future perspective

A Numerical Study of a Two-Dimensional H2-O2-Ar Detonation Using a Detailed Chemical Reaction Model

In honor of the fiftieth anniversary of the Combustion Institute, we are asked to assess accomplishments of theory in combustion over the past fifty years and prospects for the future. The title of our article is chosen to emphasize that development of theory necessarily goes hand-in-hand with specification of a model. Good conceptual models underlie successful mathematical theories. Models and theories are discussed here for deflagrations, detonations, diffusion flames, ignition, propellant combustion, and turbulent combustion. In many of these areas, the genesis of mathematical theories occurred during the past fifty years, and in all of them significant advances are anticipated in the future. Increasing interaction between theory and computation will aid this progress. We hope that, although certainly not complete in topical coverage or reference citation, the presentation may suggest useful directions for future research in combustion theory.

/pdf/combustion-theory-and-modeling-3zsa45302e.pdf

Combustion theory and modeling

We review recent progress in gaseous detonation experiment, modeling, and simulation. We focus on the propagating detonation wave as a fundamental combustion process. The picture that is emerging is that although all propagating detonations are unstable, there is a wide range of behavior with one extreme being nearly laminar but unsteady periodic flow and the other chaotic instability with highly turbulent flow. We discuss the implications of this for detonation propagation and dynamic behavior such as diffraction, initiation, and quenching or failure.

https://shepherd.caltech.edu/EDL/publications/reprints/proci_1374.pdf

Detonation in gases

Formation and evolution of two-dimensional cellular detonations

Performance comparison of oxidizer injectors in a 1-kN paraffin-fueled hybrid rocket motor

The influence of porous ammonium perchlorate (POAP) on the thermomechanical and combustion behavior of solid rocket propellants based on polyvinylchloride binder has been investigated. Differential scanning calorimetry, differential thermogravimetry, dynamic mechanical thermal analysis, and scanning electronic microscopy measurements were used for thermomechanical and thermal decomposition properties assessment. The results obtained indicate that lower glass transitions of the propellants and catalytic effect of combustion are obtained with POAP.

The influence of porosity of ammonium perchlorate (AP) on the thermomechanical and thermal properties of the AP/polyvinylchloride (PVC) composite propellants

Emulsion explosives are used in a wide range of applications, amongst which some in closed vessels, where the properties at short range need to be known. A series of tests with spherical charges has been carried out to determine the TNT-equivalent at short range of an explosive emulsion based on both peak overpressure and impulse. Generally, the value is found to be constant over the considered range, with a value of 1 for overpressure and of 0.7 for impulse. In most common applications, explosive charges are not spherical. Experiments with cylindrical charges have been performed to study the influence of (1) the shape of the charge (length-to-diameter ratio) and (2) the location of initiation (central or at one end). At the considered range, increasing L/D increases the peak overpressure and the impulse perpendicular to the axis, but decreases these effects on the axis. The central initiation causes the largest effects on the centreline. The initiation at one end causes a shift in the location of the peak overpressure, but the highest impulse remains on the centreline.

/pdf/influence-of-different-parameters-on-the-tnt-equivalent-of-4wvx4u32k8.pdf

Influence of different parameters on the TNT-equivalent of an explosion

Nitrocellulose (NC) and nitroglycerin (NG) are conventional energetic ingredients of solid double-base gun propellants. NC and NG are aliphatic nitrate ester compounds that are manufactured...

Michel H. Lefebvre

Papers

A Numerical Study of a Two-Dimensional H2-O2-Ar Detonation Using a Detailed Chemical Reaction Model

Performance comparison of oxidizer injectors in a 1-kN paraffin-fueled hybrid rocket motor

The influence of porosity of ammonium perchlorate (AP) on the thermomechanical and thermal properties of the AP/polyvinylchloride (PVC) composite propellants

Influence of different parameters on the TNT-equivalent of an explosion

Burning rate of artificially aged solid double-base gun propellants