DETERMINATION OF THE DROPLET SIZE DISTRIBUTION IN A FLOW IN A CLIMATIC WIND TUNNEL
P.A. Kondrashov, A.S. Shmakov, A.A. Sidorenko
Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch of the Russian Academy of Sciences (ITAM SB RAS), Novosibirsk, Russia
Keywords: climatic wind tunnel, icing, spray droplet size distribution, flow water content, intensity gradient, image processing
Abstract
An experimental study of the gas-droplet flow parameters was conducted in a small climatic wind tunnel at the ITAM SB RAS. The droplet size distribution of the liquid phase in the test section was determined using the PolisSpray optical shadowgraphy system. Shadowgraph images of droplets were obtained in various regions of the test section. An algorithm for droplet detection, based on a combination of gradient analysis and morphological operations, was developed and implemented to improve the accuracy of droplet size estimation. Droplet diameter distributions were obtained for the investigated regions of the test section and subsequently corrected for the effects of depth of field and optical blur. These parameters were estimated from the intensity gradient at the droplet image boundaries. The results were compared with those obtained using a Malvern Spraytec laser diffraction analyzer.
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