Study On Buoyant Jet In Density-stratified Ambient Fluid From A Rectangular Orifice

The thermal wastewater discharge of the thermal and nuclear power plants of China can usually be classified in the form of buoyant jet. The impacts on flow field and temperature field of water area which near the discharge orifice is forecasted by physical model or numerical simulation for studying mixing and diffusing regularity of cooling water which was discharged by the plants. Based on the previous studies, the research in this paper was mainly aim at the characteristics of flow field which near the rectangular orifice by physical model and numerical simulation with Particle Image Velocimetry ( PIV) system.In the physical model research, the velocity field near the outlet was measured with the PIV system, and its characteristics were particularly analyzed.In the mathematical model research, the Renormalization Group k-ε (RNG k-ε) model which was detruded from k-ε turbulent model was used. At the same time, the model equations were solved in finite volume and SIMPLE methods. The complicated 3D flow of the same water region concerned was mathematically simulated by the RNG k-ε turbulence model, the comparisons of the calculated results with the measured values showed their good agreement in whole, and some valuable results were obtained.The RNG k-ε turbulent model used in this paper was comparatively well and truly simulates the behavior of buoyant jet and the mixing characteristics in density-stratified ambient fluid. It is valuable to study the regulars of waster water in the thermal and nuclear power plants intrude into the near-sea water. It can also provide some theoretic foundations for cooling water projects.