デジタルホログラフィによる透明気流密度分布の3 次元可視化

抄録

Capturing the dynamics of rapidly changing fluids presents a major challenge in fluid mechanics. In this paper, we introduce a high-speed digital holographic tomography system designed to advance fluid dynamics research. The proposed system enables three-dimensional (3-D) visualization of fast and irregular airflow. It combines two lasers with different wavelengths, which significantly reduce interference from object beams using off-axis multiplexing. A single high-speed camera simultaneously captures holograms generated by the interference of reference and object beams from six different perspectives. In our experiments, the system successfully achieved 3-D visualization of asymmetrical airflow caused by high-pressure air breakdown, collecting data at a rapid rate of 2,000 frames per second. This enabled us to effectively track the 3-D path of the air breakdown phenomenon during discharge. Additionally, we achieved 3-D visualization of the density field of an asymmetric jet gas. This fast holographic tomography system not only provides the capability for 3-D visualization of asymmetric airflow but also holds significant importance for understanding the behavior of fluids under high-speed dynamic conditions.