Keywords

Water temperature simulation; wind sheltering model; splitting method; source-sink term

Location

Session A1: Environmental Fluid Mechanics - Theoretical, Modelling and Experimental Approaches

Start Date

12-7-2016 9:10 AM

End Date

12-7-2016 9:30 AM

Abstract

Water temperature in lakes plays an important role in aquatic ecosystem. Wind sheltering effect has an important influence on water temperature distribution. An improved wind sheltering model, which was developed to quantify wind sheltering effect, was coupled to vertical one dimensional heat conduction model to create a new water temperature model. Based on the relationship between the wind direction and obstacle location, as well as the characteristics of wind variation downwind from the obstacle, the wind sheltering model could calculate a time-dependent wind sheltering coefficient. For numerical solution, a new operator-splitting method was adopted. To compensate for the deviation caused by poor treatment of the source-sink term, the source-sink term was solved by Crank-Nicolson scheme which has second order accuracy. The numerical tests show that the proposed numerical method has higher accuracy than the traditional. It also proved that: Even the diffusion term solving by scheme has high-accuracy and good-stability, but if the source-sink term was not treated appropriately, there might still exist a large deviation. Then, the proposed model and method were applied to simulation for Guozheng Lake. The results show that: the enhanced water temperature model is an effective tool for temperature simulation.

 
Jul 12th, 9:10 AM Jul 12th, 9:30 AM

Simulation of Guozheng Lake Temperature by Using a New Water Temperature Model

Session A1: Environmental Fluid Mechanics - Theoretical, Modelling and Experimental Approaches

Water temperature in lakes plays an important role in aquatic ecosystem. Wind sheltering effect has an important influence on water temperature distribution. An improved wind sheltering model, which was developed to quantify wind sheltering effect, was coupled to vertical one dimensional heat conduction model to create a new water temperature model. Based on the relationship between the wind direction and obstacle location, as well as the characteristics of wind variation downwind from the obstacle, the wind sheltering model could calculate a time-dependent wind sheltering coefficient. For numerical solution, a new operator-splitting method was adopted. To compensate for the deviation caused by poor treatment of the source-sink term, the source-sink term was solved by Crank-Nicolson scheme which has second order accuracy. The numerical tests show that the proposed numerical method has higher accuracy than the traditional. It also proved that: Even the diffusion term solving by scheme has high-accuracy and good-stability, but if the source-sink term was not treated appropriately, there might still exist a large deviation. Then, the proposed model and method were applied to simulation for Guozheng Lake. The results show that: the enhanced water temperature model is an effective tool for temperature simulation.