High-speed imaging is in popular demand for a broad range of scientific applications, including fluid physics, and bubble and droplet dynamics. It allows for a detailed visualization of the event under study by acquiring a series of images captured at high temporal and spatial resolution. The challenge here is the combination of microscopic length scales and ultrashort time scales associated with the mechanisms governing fluid flows. In this chapter, ultra high-speed imaging at frame rates exceeding 10 million frames per second (fps) is briefly reviewed, including the emerging ultrafast sensor technologies and ultrashort nanoseconds flash illumination techniques. We discuss in detail the design and applications of the Brandaris 128 ultra high-speed imaging facility. The high-speed camera combines the optical frame of a rotating mirror camera with 128 CCD sensors and can record at a maximum frame rate of 25 Mfps. Six acquisitions can be stored in the on-board memory buffer, while in a segmented mode images are acquired in subsets, e.g. 24 x 32 frames, allowing parametric studies to be performed. We also discuss how the Brandaris camera is operated to capture details of bubble dynamics, droplet vaporization, and inkjet printing.
|Title of host publication||The Micro-World Observed by Ultra High-Speed Cameras: We See What You Don't See|
|Number of pages||29|
|Publication status||Published - 30 Aug 2017|