Effects of Submergence Ratio and Undersurface Roughness on Flow Separation Beneath Simulated Ice Covers

加拿大各地许多水电公司的液压系统的运行每年大约有6个月受到河冰过程的直接影响。这些复杂的河冰过程的净影响之一是，在恰逢年度能源需求峰值的时候，液压系统的输送和运行效率下降，导致发电收入损失，并面临不同程度的运行风险。随着气候变化，这些过程的复杂性和严重性可能会增加，因此有必要开发准确的数值模型。马尼托巴大学的研究人员将与马尼托巴水电公司密切合作，通过实验研究水力条件的变化如何影响冰盖下的非恒定流特性和湍流输送过程。这些实验将使用最先进的粒子图像测速仪在循环开放水道中进行。这项研究将推进不同淹没比和地下粗糙度的模拟冰盖下湍流分离的科学知识，并提供全面的数据集，使水力研究界的研究人员能够开发和验证可靠的数值模型来预测冰盖下复杂的湍流流动。这些数值模型将使水利工程人员能够可靠地预测水流阻力和流量，以及它们对冰塞形成、洪水、泥沙输送和河床侵蚀的潜在影响。

The operation of hydraulic systems of many hydro companies across Canada are directly affected by river ice processes for approximately 6 months each year. One of the net effects of these complex river ice processes is a decrease in conveyance and operational efficiency of hydraulic systems at a time that coincides with the peak annual energy demand, resulting in lost generation revenue and exposure to varying levels of operational risk. These processes will likely increase in complexity and severity with climate change, necessitating the need for developing accurate numerical models. In close collaboration with Manitoba Hydro, researchers at University of Manitoba will experimentally investigate how changes in hydraulic conditions affect the unsteady flow characteristics and turbulent transport processes beneath ice covers. The experiments will be performed using a state-of-the-art particle image velocimetry in a recirculating open water channel. The research will advance the scientific knowledge of turbulent flow separation beneath simulated ice covers of varying submergence ratio and undersurface roughness, and provide comprehensive datasets that will enable researchers in the hydraulic research community to develop and validate reliable numerical models for predicting complex turbulent flow beneath ice covers. These numerical models will enable hydraulic engineers to reliably predict flow resistance and discharge, and their potential impact on formation of ice jam, flooding, sediment transport and erosion of river beds.