Combined Effects of Wind and Streamflow on Gas-Liquid Transfer Rate

Abstract

A theoretical model is developed to predict the wind-streamflow-driven gas-liquid transfer rate. When wind blows over the stream surface, turbulence is generated at both the air-water interface and the water-bed interface, which is the driving force of the surface renewal movement of water parcels. The total surface renewal rate is considered as the sum of the effective surface renewal rates driven by the turbulence generated at these two interfaces. The gas-liquid transfer rate is formulated as a function of the total surface renewal rate based on the surface renewal theory. The concept of serial resistance, shear velocity, and effective viscous layer play significant roles in the model development. This model correlates the gas-liquid transfer rate with the dynamic fluid parameters such as wind speed and stream velocity. The predictions of this model show good agreement with existing experimental data. This model can be applied to predict the gas-liquid transfer rate in wind-streamflow-driven systems.