Vortex Formation During Liquid Draining from a Cylindrical Tank with Conical Bottom—A Numerical Study

This paper deals with a numerical study on the Rankine vortex formation during liquid draining from cylindrical tanks with conical base. ANSYS-Fluent was used for the numerical simulation. A liquid column contained in a cylindrical tank with conical bottom is rotated and then drained through a centrally located drain port situated at the base of the tank. For this, various values of initial rotation of liquid (n rpm) were considered. For each ‘n’, angle of the bottom base (Ф) and drain port diameters (dp) were varied over a broad range in an attempt to suppress the vortex formation. Results indicate that as ‘Ф’ is increased, the critical height decreases (hc); i.e., vortex is more suppressed. Also, higher vortex suppression occurs at larger port diameters for a given Ф. Reynolds number and Froude number are found to significantly influence the vortex formation, whereas Weber number is found to be non-influential.