Phys.org March 6. 2023
Unburnt hydrocarbon flames produce soot which is the second biggest contributor to global warming. The state-of-the-art high-speed imaging techniques do not provide a complete picture of flame-laser interactions, important for understanding soot formation. An international team of researchers (USA – Caltech, Washington University, Sweden, Germany) has developed single-shot laser-sheet compressed ultrafast photography (LS-CUP) for billion-frames-per-second planar imaging of flame-laser dynamics. They observed laser-induced incandescence, elastic light scattering, and fluorescence of soot precursors – polycyclic aromatic hydrocarbons (PAHs) in real-time using a single nanosecond laser pulse. The spatiotemporal maps of the PAHs emission, soot temperature, primary nanoparticle size, soot aggregate size, and the number of monomers, present strong experimental evidence in support of the theory and modeling of soot inception and growth mechanism in flames. According to the researchers LS-CUP represents a generic and indispensable tool that combines a portfolio of ultrafast combustion diagnostic techniques, covering the entire lifecycle of soot nanoparticles… read more.TECHNICAL ARTICLE Open Access  1 , 2Â
12.5-Gfps LS-CUP imaging of elastic light scattering (ELS) of soot particles. Credit: Light: Science & Applications volume 12, Article number: 47 (2023)Â