Round turbulent buoyant jets discharged vertically upwards forming a regular polygon

Abstract

The simplified partial differential equations of momentum and tracer for the mean motion are integrated on the reduced cross-sectional area within the field of one buoyant jet from a group issued vertically upwards from a rosette-type riser. The solutions yield the dimensionless centerline axial velocities and concentrations. Mathematically, the one-jet field is separated from the entire group by employing the Entrainment Restriction Approach (ERA) applicable in interacting buoyant jets with symmetry planes. ERA was herein improved by incorporating the Second Order Approach (SOA). Interaction effects are highlighted by normalizing the mean-flow properties. The role of buoyancy on merging is introduced by a dynamic parameter, which combines proximity effects with buoyancy, thus termed dynamic proximity number. In addition, the distributions for mean dilution, kinetic energy flux and local Richardson number are also predicted, discussed, and compared with data reported in the literature. Findings may be useful for design purposes and environmental impact assessment.

Keywords:

• Buoyant jet
• entrainment restriction
• integral model
• mean flow properties
• multiport diffuser
• rosette-type riser
• sea outfall