Meyer Terrence R, Halls Benjamin R, Jiang Naibo, Slipchenko Mikhail N, Roy Sukesh, Gord James R
Opt Express. 2016 Dec 26;24(26):29547-29555. doi: 10.1364/OE.24.029547.
High-speed, laser-based tomographic imaging of the three-dimensional time evolution of soot volume fraction in turbulent jet diffusion flames is demonstrated to be feasible at rates of 10 kHz or higher. The fundamental output of a burst-mode Nd:YAG laser with 1 J/pulse is utilized for volumetric impulsive heating of soot particles with a laser fluence of 0.1 J/cm, enabling signal-to-noise ratios of ~100:1 in images of the resulting incandescence. The three-dimensional morphology of the soot distribution is captured with a spatial resolution of <1.5 mm using as few as four viewing angles, with convergence of the soot volume fraction to within ~95% occurring with seven or more viewing angles. Uniqueness of the solution is demonstrated using two sets of eight images captured at the same time instant, with agreement to >90% in peak values between the two sets. These data establish parameters for successful high-speed, three-dimensional imaging of the soot volume fraction within highly transient combustion environments.
