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水内冰的形成演变与冰塞形成密切相关,而冰塞常造成严重的凌洪灾害。为此研究并建立了河道中水内冰形成及演变的垂向二维紊流数学模型,应用模型对敞露河道水内冰演变过程及水温和体积分数分布规律进行了数值实验。数值模型中,假定水内冰的初始成核源于水表面冰晶籽的质量交换,冰晶粒径的演变取决于冰晶与周围水体间的热交换。根据原型观测结果,水内冰冰晶的形状假定为薄圆盘状。计算结果表明,水内冰体积分数沿水深呈指数分布,且沿程持续增加,而水温沿程出现最小值。这些结果与理论分析相符,说明该模型能较好地模拟河道中水内冰的演变。
The formation and evolution of ice in the water is closely related to the formation of ice plugs, and ice plugs often cause severe flood disasters. For this reason, a vertical two-dimensional turbulence mathematical model for the formation and evolution of inner-ice in the river water was studied and established. The model was used to simulate the evolution of the inner ice and the distribution of water temperature and volume fraction. In the numerical model, it is assumed that the initial nucleation of ice in water originates from the mass exchange of ice crystals on the water surface. The evolution of ice particle size depends on the heat exchange between the ice crystals and the surrounding water. According to the prototype observations, the shape of ice crystals in water assumes the shape of a thin disc. The calculation results show that the volume fraction of ice in water is exponentially distributed along the water depth and increases continuously along the water depth, while the minimum value appears along the water temperature. These results are consistent with the theoretical analysis, indicating that the model can better simulate the evolution of water ice in the watercourse.