Jet Integral–Particle Tracking Hybrid Model for Single Buoyant Jets

The mixing processes of a buoyant jet discharged from a submerged single port were analyzed using a three-dimensional hybrid model. In the proposed hybrid model, the initial mixing was simulated by a jet integral method, and the advection-diffusion process was simulated using a particle tracking method. Laboratory experiments were conducted for various flow conditions in order to verify the proposed model. The simulated horizontal concentration distributions and minimum dilutions at the water surface were generally in agreement with the observations. The vertical concentration distributions for coflowing jets were well simulated by both the jet integral and the particle tracking methods of the hybrid model. Trajectories simulated by the jet integral module of the hybrid model were in agreement with the measured trajectories when the velocity ratio was low. For cases where the velocity ratio was high, the hybrid model in which the vortex-pair distribution was used gave better results than the hybrid model with only Gaussian velocity distribution.