Surface Discharge of Heated Water, Part II: The Two-Dimensional Buoyant Surface Jet and the Internal Hydraulic Jump

Abstract

A theoretical and experimental study of the two-dimensional flow of heated water from a channel into a deep reservoir filled with cold water was made. Only flows producing a dilution of warm water by entrainment of cold water were investigated. These flows consisted of a mixing zone near the outlet followed downstream by a stratified flow. The outlet flow characteristics, the type of downstream control, and the geometry of the transition were identified as the essential controlling parameters for the entrainment. The amount of vertical entrainment in the mixing zone at the outlet was calculated and measured. The flow in the mixing zone where the entrainment is produced was found to be a combination of a buoyant half jet with an inverted internal hydraulic jump. The simultaneous presence of both inertial and buoyant forces was responsible for this occurrence. Theoretical and experimental results show that substantial dilution occurred in the outlet mixing zone, but actual rates of entrainment were quite sensitive to changes in flow conditions. This report was submitted in fulfillment of Project Number 16130 FSU under the sponsorship of the Water Quality Office, Environmental Protection Agency.