Affiliations: Division of Energy and Environmental Systems, Graduate
School of Engineering, Hokkaido University, Sapporo, 060-8628, Japan. E-mail:
murai@eng.hokudai.ac.jp
Abstract: Particle tracking velocimetry (PTV) is applied for measuring the
motions of luminous particles in fireworks. The objective of the study is to
clarify the technical problems encountering in large-scale quantitative
visualization in natural environment. The major problems are found to be
uncontrolled background in nature, low pixel resolution relative to particle
size, and large perspective. The ways to deal with these problems in current
technological level are discussed. In the application, two cameras are located
at 1.3 km from the launching point with 30-degree opening angle to implement
3-D PTV. The transient 3-D velocity distributions of around 200 m-scale
diameter fireworks are obtained during the light emission from the explosion
till burnout. Moreover, the evolution of the mean particle diameter that
decreases continuously with the combustion is estimated with the measured
velocity information by the particle's equation of motion.
Keywords: Visualization, PTV, Telescopic Imaging, Firework, And Three-Dimensional Flow