Research has shown that oscillatory or modulated flows can achieve a significant increase in heat transfer relative to the corresponding steady flow, providing that critical or threshold amplitude is achieved. The threshold condition is associated with the production of near-surface turbulence by the oscillatory motion. A similar process is hypothesized as a mechanism of highamplitude acoustic ...

This paper studies the propellant and levitation forces of a prototype maglev system where the propellant forces are provided by a linear motor system. For this purpose, the mathematical model and method using finite element method coupled to external circuit model is developed. The details of the propellant and levitation forces for a prototype maglev system under different operating condition...

This paper presents a dynamic model of the interior ballistics of an experimental liquid propellant-powered rifle. The liquid propellant-powered rifle described utilizes a mixture of Hydroxyl Ammonium Nitrate (HAN) and hydrocarbon fuel to replace gunpowder typically used in such firearms. The motivation for such a development is to discard the need for a shell casing whereby carrying only prope...

The “Advanced Propellant/Additive Development for Gas Generator” project is a collaborative effort between General Dynamics Ordnance and Tactical Systems (GD-OTS) and the Naval Air Warfare Center-Weapons Division (NAWCWD). The objectives of this NGP project are to develop new highly efficient, environmentally acceptable, chemically active fire suppressant capabilities based upon solid propellan...

Energetic materials (explosives, propellants, and pyrotechnics) are used extensively for both civilian and military applications and the development of such materials, particularly in the case of energetic salts, is subject to continuous research efforts all over the world. This Review concerns recent advances in the syntheses, properties, and potential applications of ionic salts based on tetr...

Hypersonic air breathing propulsion system has been in the minds of human being for a very long time. Ramjet propulsion provides efficient operation along with very high specific thrust and is very attractive for gun launch ramjet projectiles, hypersonic cruise vehicles and hypervelocity missiles. In the present investigation, Zr based fuel rich propellants in NC-NG matrix and HTPB matrix were ...

This paper extends the classical analytical solution for small perturbation analysis of the pressure-coupled response of a homogeneous propellant to any two-component composite propellant. The solution obtained is general and can be used with any particular model for propellant combustion. As an example, the Cohen and Strand ammoniumperchlorate propellantmodel for a single ammoniumperchlorate p...

A novel method for the characterization and qualification of Hall effect thruster propellant distributors is presented. A quantitative measurement of the azimuthal number density uniformity, a metric which impacts propellant utilization, is obtained from photographs of a premixed flame anchored on the exit plane of the propellant distributor. The technique is demonstrated for three propellant d...

In this study, a novel technique for evaluating continuously burning rate of cylindrical cores made of a solid homogeneous propellant is presented. The propellant core was placed in the tube made of pyrolytic graphite (pyrographite). The burning rate of the rocket propellant has been determined by monitoring the burning front/zone movement on the external surface of the pyrographite tube by usi...

A study was conducted to measure the variation in propellant properties for three consecutive batches of an identical formulation. A secondary study was performed to assess the effect of casting vacuum on propellant density, hardness, mechanical properties and burn rate. Only small differences in properties between batches were evident and most were assessed as being within the uncertainty of t...