Application of a digital high-speed camera system for combustion research by using UV laser diagnostics under microgravity at Bremen drop tower

This paper describes a digital high-speed camera- and recording system that will be used primary for combustion research under microgravity ((mu) g) at Bremen drop tower. To study the reactionzones during the process of combustion particularly OH-radicals are detected 2D by using the method of laser induced predissociation fluorescence (LIPF). A pulsed high-energy excimer lasersystem combined with a two- staged intensified CCD-camera allows a repetition rate of 250 images (256 X 256 pixel) per second, according to the maximum laser pulse repetition. The laser system is integrated at the top of the 110 m high evacutable drop tube. Motorized mirrors are necessary to achieve a stable beam position within the area of interest during the drop of the experiment-capsule. The duration of 1 drop will be 4.7 seconds (microgravity conditions). About 1500 images are captured and stored onboard the drop capsule 96 Mbyte RAM image storagesystem. After saving capsule and datas, a special PC-based image processing software visualizes the movies and extracts physical information out of the images. Now, after two and a half years of developments the system is working operational and capable of high temporal 2D LIPF- measuring of OH, H2O, O2, and CO concentrations and 2D temperature distribution of these species.