Although inhalation is one of the oldest modes of drug delivery, it is currently receiving renewed attention. Prior to 1987, aerosolized therapeutics were delivered via systems that relied on chlorofluorocarbon propellant systems. The subsequent ban on all nonmedical uses of these inert gases stimulated pharmaceutical companies to investigate other propellant systems. Two hydrofluoroalkanes wer...

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...

We present a method that combines multiple sensory modalities in rocket thrust chamber to predict impending thermoacoustic instabilities with uncertainties. This is accomplished by training an autoregressive Bayesian neural network model forecasts the future amplitude of dynamic pressure time series, using sensor measurements (injector pressure/ temperature measurements, static pressure, high-f...

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...

1. Pulsed Plasma Thruster Pulsed plasma thrusters (PPTs) are expected to be used as a thruster for a small satellite. The PPT has some features superior to other kinds of electric propulsion. It has no sealing part, simple structure and high reliability, which are benefits of using a solid propellant, mainly Teflon (poly-tetrafluoroethylene: PTFE). However, performances of PPTs are generally lo...

Busek Co. Inc. completed delivery of flight-qualified colloid thrusters for NASA’s ST7 mission in May 2008. This effort has led to development of variants of the technology suitable for small satellite applications. Colloid thrusters operate by electrostatically accelerating charged droplets of an electrically conductive ionic liquid, and are capable of providing a high degree of throttling and...