Research in energetically enhanced combustion...

is dedicated to looking at new technologies which can be applied to actively enhance the combustion process. One novel method of enhancing the reactivity of liquid fuels is to add energetic nanoparticles which can accelerate the thermal oxidation chemistry. Energetic nanoparticles have already shown to be effective in fuel slabs of rocket motors, and efforts are underway to see if their use can be extended to conventional liquid fuels.

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Energetic Nanoparticles

Energetic nanoparticles are nano-sized (10 to 100 nm range) particles, usually metallic with a passivated oxide layer, and are characterized by a high rate of energy release. Energetic nanoparticles offer a high volumetric heat of oxidation, enabling transportation of more energy per given fuel volume. When mixed in a fuel or a composite, they generally exhibit faster ignition timescales due to the dramatic increase in the surface-to-volume

ratio, and can ignite below the bulk melting point of the metal. Left picture shows Al nanoparticles currently being used in our lab.

Supported by the Department of Energy

Fuel Droplet Distribution in the RCM

To ensure that the discharge of liquid droplets into the RCM is uniformly dispersed, we have conducted laser scattering measurements using a glass replica of the combustion chamber and an intersecting laser sheet. These results were used to optimize the poppet valve setup for specific fuel and nanoparticle blend.

Al nanoparticle enhanced JP-8

2% nanoparticle (by weight) laden JP-8 combustion tests in the RCM for various pressures showed that roughly 40% reduction in ignition delay could be observed. The rate of pressure rise also showed a dramatic increase when the Al nanoparticle was added to the fuel. Similar decrease in the ignition delay was  also observed for ethanol blended with similar levels of Al nanoparticles. Identification of the mechanism for these effects are under investigation.