中文摘要：

以西安金盆水库为例,建立了分层水库水温结构的数值模拟方法,并以实测数据进行模型验证.运用Fluent软件数值研究了不同短波辐射强度及短波辐射衰减系数条件下温跃层的形成过程与特性.水库水面总传热量在春、夏季为正值,在秋、冬季为负值,长波辐射是水面总传热量的主要影响因素,短波辐射则是温跃层形成的主要影响因素.随短波辐射衰减系数的降低,温跃层厚度增加,温跃层内温度梯度减小,短波辐射衰减系数值与实测的藻类浓度存在良好的正相关性.水库具有极限短波辐射强度,温跃层内温差随水面短波辐射强度的增加呈现先增加后减小的变化趋势;但水面短波辐射强度过高时,难以达到热平衡而形成稳定的温跃层.

英文摘要：

Taking Jinpen Reservoir in Xi＇an as a study case, a numerical simulation method for thermal structure of a stratified res- ervoir was developed and validated against the field data. The development and characteristics of the thermocline under various con- ditions of short wave radiation and bulk extinction coefficient for short wave radiation was numerically investigated by using a com- mercially-available software of Fluent. The net total surface heat transfer is positive in spring and summer, while negative in au- tumn and winter. The long wave radiation mainly contributes to the net total surface heat transfer, while the short one controls the development of the thermocline. The depth of the thermocline increased and the temperature gradient over the thermocline de- creased as the bulk extinction coefficient decreased, and the bulk extinction coefficient is positively related to the algae concentra- tion. There was a maximum value of the surface short wave radiation for a certain reservoir, the temperature difference between the top and bottom of the thermocline increased when the short wave radiation was below the maximum radiation, but it decreased when the short wave radiation was beyond the maximum radiation. Moreover, a heat balance and a stable thermocline can＇t be easily de- veloped under higher short wave radiation.