Cool Diffusion Flames and Their Applications on Earth

Abstract

Cool diffusion flames are a type of diffusion flame that burns at a much lower temperature (~700 K) than a traditional hot flame. Discovered in 2012 on the ISS, these flames have been a growing research topic for the last decade. These flames are observed at UMD through a dual hot plate setup in which a pool of a liquid hydrocarbon is heated. An intensified camera and color camera were used to view the movement of the flames and take pictures of the flames, respectively. Thermocouples attached to the apparatus output temperatures of both plates as well as the flame temperature. An anemometer was used to measure flow in the vent above the apparatus, and a formaldehyde sensor was used to track formaldehyde yield of the flames. The fuel that created the most stable flame, n-heptane, was found to work best at a lower heater temperature of 105-110 degrees Celsius and an upper heater temperature of 400-420 degrees Celsius. The peak temperatures of these flames rested between 420-440 degrees Celsius (693-713 K). It is possible that cool flames could be applicable to increasing efficiency in gasoline engines by using them to ignite the hot flame. Results from these experiments could help to improve the accuracy of models that can simulate these technologies.