Optical investigation and recording of fast repetitive events

Kurzfassung

The framing rate of the commonly-used video cameras according to the video standards CCIR / EIA is constant, equal to 25/30 frames per second. For the video recording of very fast events, special, non-standard, high-speed cameras working on sophisticated principles have to be applied. Such systems however, are all extremely expensive and have, due to their principle of operation, several disadvantages such as limited number of the recorded frames in the sequence, low spatial resolution and large, heavy camera heads. The system developed by the author, called high-speed video stroboscope, is suitable for the imaging of fast repetitive events, specially for periodic ones. It provides on the computer monitor a real-time, slow-motion display of fast moving objects and is capable of recording long sequences of high-quality images. A pulsed illumination is not necessary. It has been applied already amongst others in the investigation of visualized flows, machine motion, design and diagnostics of engines and turbines, fuel injection, disintegration of micro-jets, ship propeller cavitation, human larynx vibration and insect flight. The principle of its operation and the results of various experiments will be presented and illustrated with acquired video clips.