Three-Dimensional Numerical Modeling of Large-Scale Free Surface Flows with Heat and Contaminant Transfer in Reservoirs

Abstract

The temperature distribution and pollutant distribution in large reservoirs have always been a hotspot in the field of hydraulics and environmentology, and the three-dimensional numerical modeling that can effectively simulate the interactions between the temperature fields, concentration fields, and flow fields needs to be proposed. The double-diffusive convection lattice Boltzmann method is coupled with a single-phase volume of fluid model for simulating heat and contaminant transfer in large-scale free surface flows. The coupling model is used to simulate the double-diffusive natural convection in a cubic cavity and the temperature distribution of a model reservoir. The mechanism of convection-diffusion, gravity sinking flow, and the complexity of the temperature and the pollutant redistribution process are analyzed. Good agreements between the simulated results and the reference data validate the accuracy and effectiveness of the proposed coupling model in studying free surface flows with heat and contaminant transfer. At last, the temporal and spatial variations of flow state, water temperature stratification, and pollutant transport in the up-reservoir of a pumped-storage power station are simulated and analyzed by the proposed model. The obtained variations of the flow field agree well with the observations in the physical model test and in practical engineering. In addition, the simulated temperature field and concentration field are also consistent with the general rules, which demonstrates the feasibility of the coupling model in simulating temperature and pollutant distribution problems in realistic reservoirs and shows its good prospects in engineering application.