163. flames... out of this world
Name: Luca Carmignani
Grad Year: 2019
The behavior of flames in microgravity has been studied for the last few decades, to improve the fundamental knowledge of combustion processes and create a relatively safe environment for astronauts. The evolution of flames over thin solid fuels burning with an opposing flow velocity between 0 and 50 cm/s (typical of ventilation systems) depends on many factors, such as fuel composition, thickness, oxygen concentration, magnitude of the opposing flow and so on. Flame spread rate - speed of the flame along the spreading direction - is an overall property that characterizes the flame behavior. Experimental values and their variations due to external factors such as oxygen level and opposing flow velocity are reported and compared. Results are obtained processing videos of the experiments with a MATLAB code we developed, called Flame Image Analyzer Tool (FIAT). The distance from the flame leading edge to the end of the flame (flame length) is calculated from the experiments, and the trend for different conditions agrees with computational results obtained with a CFD code coupled with a radiation code, written by Dr. Bhattacharjee. Experiments were conducted in the Microgravity Science Glovebox on the International Space Station, using thin sheets of acrylic material (PMMA). Fuel thickness, sample width, flow velocity, and the oxygen level were varied in these experiments. Also, flames burning in similar conditions but different sample width change significantly in dimensions, color and curvature of the leading edge, suggesting a three-dimensional nature of the process.
Industry Application Area(s)
Aerospace, Defense, Security