Flow Phenomena and Heat Transfer Around a Sphere Submerged in Water Jet and Bubbling Jet

Abstract

Velocity and turbulence around a sphere made of synthetic resin submerged in water and bubbling jets in a cylindrical vessel with bottom blowing were measured by making use of Laser Doppler Velocimeter (LDV). The melting process of an ice sphere was recorded by video camera. The local Nusselt number [formula ommitted] of the ice sphere was determined from the initial change of the local radius. The mean Nusselt number A/o was calculated from [formula ommitted] by numerical integration over the surface of the sphere. The effects of velocity and turbulence intensity on [formula ommitted] and [formula ommitted] were investigated. An empirical expression for [formula ommitted] was proposed as a function of Reynolds number and turbulence intensity. A method of predicting the complete melting time of an ice sphere was presented. © 1989, The Iron and Steel Institute of Japan. All rights reserved.