Numerical Investigation on Critical Submerged Depth During Draining From Cylindrical Tanks

Gas ingestion arises from free surface dip during draining from liquid storage tank does serious damage to the nuclear engineering practices, which should be considered in the design work. In this article, numerical simulations of transient process of draining from cylindrical tanks have been conducted with volume-of-fluid (VOF) method, by using the commercial CFD code FLUENT14.5. The relation between critical submerged depth and the Froude number has been investigated, then the influence of different factors on critical submerged depth also has been discussed. The results show that the Jain’s empirical formula are available to estimate the critical submerged depth flow with weak vortex in the condition of high diameter ratio and high initial water level. Moreover, the initial strong vortex significantly increase the critical submerged depth, while the surface tension has pretty small effects on the critical submerged depth when the Froude number is large.