摘要
采用基于无结构三角网格的有限体积法,建立了模拟复杂滩区地形上漫滩洪水演进的二维水动力学模型。利用已有室内溃坝试验资料对模型进行了验证,所得计算结果与实测资料较为符合。最后采用该模型计算了黄河下游典型滩区洪水的演进过程,分析了不同网格尺度及村庄区域糙率取值对模拟结果的影响。结果表明:网格大小及糙率取值对模拟结果均存在不同程度的影响,计算区域中剖分的网格尺度并非越小越好,而是应保证与实测高程点的密度基本相适;村庄区域挖空或取不同糙率值对洪水演进影响显著,挖空工况下水深增加最大值为0.57m,曼宁糙率取值0.12时的水深比糙率取值0.06时大0.25 m,相应流速减小0.24 m/s。在实际工程计算中,村庄区域按照当量糙率处理方式更为合理,但具体取值应结合实测资料进行验证。
A two-dimensional hydrodynamic model using a TVD finite volume method and unstructured triangular mesh is presented for prediction of the routing of overbank floods over complex floodplain topography. This model has been verified against the previously reported experimental data of dam-break flows in a laboratory flume, and a favourable agreement was achieved between the model predictions and measurements. We applied the verified model to an overbank flood event on a typical floodplain of the Lower Yellow River, and examined in detail the effects of mesh scale and village region roughness on the predictions. The results show that these two factors have influences of different degrees. Smaller mesh scales cannot achieve better results, but reasonable scales should be those that conform to the density of bed elevation points measured. Predictions of flood inundation by using center-hollowed village regions and different village roughness values were significantly different. In the center-hollowed case, an increase of up to 0.57 m in the maximum water depth was calculated, relative to the roughness modelling. An increase in village roughness from 0.06 to 0.12 caused an increase of 0.25 m in the maximum water depth and a reduction of 0.24 m/s in the flow velocity. Thus, in practical engineering applications, conceptualization and modelling of village regions and their roughness values should be determined according to real conditions.
作者
张晓雷
夏军强
李娜
ZHANG Xiaolei XIA Junqiang LI Na(State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072 School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou 450011 Department of Water Hazard Research, China Institute of Water Resources and Hydropower Research, Beijing 100038)
出处
《水力发电学报》
EI
CSCD
北大核心
2016年第10期48-57,共10页
Journal of Hydroelectric Engineering
基金
国家自然科学基金(51379156
51579186)
水利部公益性行业科研专项经费项目(201401038
201401023)
关键词
洪水演进
水动力学模型
网格尺度
村庄糙率
漫滩洪水
flood inundation
hydrodynamic model
mesh scale
village roughness
overbank flood
