Turbulence Structure of Bottom-Blowing Bubbling Jet in a Molten Woods Metal Bath

The coherent structure of turbulence in a vertical He-Woodʹs metal bubbling jet formed in a cylindrical vessel was investigated using the four-quadrant classification method. Turbulent motions of molten Woodʹs metal flow were classified into four distinct categories: ejection (higher-momentum fluid motion, directed outward), sweep (lower-momentum fluid motion, directed inward), outward interaction (lower-momentum fluid motion, directed outward), and inward interaction (higher-momentum fluid motion, directed inward). The relative occurrence in frequency of each turbulent motion and the contributions of each turbulent motion to the axial and radial turbulence kinetic energies and Reynolds shear stress were determined. These quantities were different from their respective values in an air-water vertical bubbling jet. Such differences were found to be closely associated with the fact that the shape and size of bubbles differs significantly between the two bubbling jets. Consequently, the coherent structure of turbulence in a bubbling jet is strongly dependent on the behavior of the wake behind the bubbles.