Best practice procedures on two-phase flow experiments for CFD validation

The high-speed camera had a rapid progress in early 2000's. The C-MOS chip camera now can record 7,500 frames per second (fps) with 1 M pixel image resolutions. We can capture 30,000 fps images with VGA image resolution. These images have both of high-temporal and high-spatial resolutions. The two-phase flow and boiling phenomena are usually highly non-linear and need high-temporal and high-spatial resolutions to extract the physics. Therefore, the C-MOS based high-speed camera is the strong tool to extract the complicated basic structures of two-phase flows. One of the key issues of the two-phase flows is the moving boundary. High-speed camera is the strong tool to measure the moving boundary. On the image, both of the boundary motion and tracer particle could be simultaneously measured. Therefore, if the flow field were two-dimensional, only one high-speed camera is needed to capture the structures. The interaction between the flow and moving component, e.g., bubbles, structures and droplets, were precisely evaluated using the Dynamic PIV system. (author)