Prediction of Flow and Oxygen Transfer by a Plunging Water Jets with Genetic Expression Programming (GEP) Models

A plunging water jet passing through the surrounding air entrains a large amount of air bubbles into a pool and forms a large submerged two-phase (gas-liquid) contacting area. This process is called air entrainment or aeration by a plunging water jets. In this study, the flow characteristics such as volumetric air entrainment rate, bubble penetration depth and oxygen transfer efficiency are evaluated based on five major parameters which describe air entrainment at the plunge point: the nozzle diameter, jet length, jet velocity, nozzle length-to-diameter ratio and jet impact angle. This paper presents gene expression programming (GEP) model, which is an extension to genetic programming, as an alternative approach to modeling of the flow characteristics such as the bubble penetration depth, air entrainment rate and oxygen transfer efficiency by plunging water jets. New formulations for prediction of the flow characteristics in the plunging water jet system are developed using GEP and regression models.