Author(s): Yongping Chen, Yongping Chen, Zhenshan Xu
Keywords: Near field; Buoyant jet; Wave-current flow; Integral model; Wastewater;
Abstract: Coastal discharge has been a frequently used wastewater treatment in recent years, which may cause adverse environmental and ecological impacts on the coastal zone. It is of great importance to understand and predict the behaviors of wastewater movement, which is usually in the form of buoyant jet, under complex coastal dynamic conditions. In the near field, the discharged jet is not only driven by its initial momentum, but also affected by various coastal dynamics such as tides and waves. Previous studies mainly focused on the crossflow only or wave-only effect on the characteristics of the buoyant jet or on a momentum jet in a wave-current flow, while it is lack of investigations on the buoyant jet under the effect of wavy crossflow. In this study, we aim to understand and predict the characteristic behaviours of a buoyant jet in a wavy crossflow environment, by use of an integral model. The model is developed by employing an entrainment closure approach that distinguishes the contribution of transverse shear and that of azimuthal shear mechanisms. Furthermore, the model contains a quadratic law turbulent drag force mechanism. Four cases of jet in the wavy crossflow environment are computed and compared with in prior experimental results. It is found that the integral model can be used to predict the behaviors of the buoyant jet under the wave and current environment and concentration distribution of jet in wavy-crossflow become more uniform than that of the jet in crossflow.