Abstract
The flow field in vertical bubbling jet in a cylindrical vessel was found to be divided into four regions. They were named the momentum, transition, buoyancy and surface regions from the nozzle exit toward the bath surface. However, the bubble characteristics in each region have not been made clear even in air-water bubbling jets. The present paper proposed empirical correlations for bubble frequency and gas holdup in the momentum region of air-water vertical bubbling jet. The momentum region was defined as the region where the gas holdup on the centerline decreased from 100 to about 10%. These correlations were applicable to bubbling jets of the modified Froude number from about unity to 2×105.