Numerical Study on Mixing Characteristics of Heated Water Discharged from Side Outfall with a Cross Flow

To investigate the mixing characteristics of heated water discharged, a three-dimensional flow and heated water advection-dispersion model was used to numerically study the buoyant flow, along with its mixing characteristics, of heated water discharge form side outfall with a cross flow. Hydraulic experiment data were used to evaluate the applicability of the model. The simulation results agree well with the experimental results, particularly, the jet trajectories, the dimensions of the recirculation zone, and the vertical distribution of the dimensionless excess temperature. Meanwhile, multi-group numerical experiments are set up with different momentum flux ratio and different discharge densimetric Froude number. The discharge jet is deflected by the ambient cross flow, while forcing the ambient flow to bend towards the far bank for the full depth. Counter clockwise circulation and local eddies form with the increases of momentum flux ratio. The recirculation zone is the largest in the lowest layer but becomes smaller in the upper layer due to the effect of density gradient. As the momentum flux ratio increases, the ambient cross flow goes over the jet so that jet bending decreases. The envelope area and envelope volume of dimensionless excess temperature increases with the increases of the discharge densimetric Froude number.