Experimental study on splash ratio and size of secondary droplets during liquid JET collision onto a solid surface

If liquid sodium leaks as a liquid jet from pipe in sodium-cooled fast reactors, sodium droplets are produced during liquid jet impingement on the structures. Due to large contact area with surrounding air, generation of secondary droplets may lead to violent fire combustion. In the present work, high speed camera was first used to observe the liquid jet before the impingement. The splash ratio was then measured experimentally. It was shown that a phenomenological model using the impact frequency and the impact Weber number as the important variables can predict the splashing rate well. Distribution of the secondary droplet size was also measured by image analysis. It was indicated that the Sauter mean diameter of the secondary droplets was fairly proportional to the size of primary droplets. (author)