排序方式: 共有15条查询结果,搜索用时 31 毫秒
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在单向水槽中对沙纹的形成及演化机理进行试验研究,通过改变床面剪切应力来研究沙纹的形成过程,探讨了床面存在的主要扰动形式,并分析了沙纹的形成机理。 相似文献
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修造船坞中卧倒门起卧时的稳定性受水流动力的影响较大。基于RANS方程,利用RNG k-ε双方程紊流模型进行封闭,采用VOF方法跟踪自由水面,对干船坞气控式卧倒门的起浮过程进行了动网格模拟计算。综合考虑三种水位下坞门起卧时的流动特性,结合模型试验数据分析流场和紊动动能随坞门起浮时的变化,为坞门的动力特性分析和坞门设计提供依据。计算结果表明,伴随着顺时针和逆时针涡动结构的快速发展,紊动动能主要集中于铰座、前面板的上端和后门角三处附近水域。随着水位抬升,此三处的紊动动能亦呈现增大趋势,涡动的变化范围加大,尤其是水下运行阶段和关闭阶段,铰座处水域的门坑将受到最强烈的冲击。 相似文献
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港口与航道虹吸灌水廊道广泛应用在近年来新建的修造船坞中,流量系数是评价其性能的重要水力指标。结合某修船坞虹吸灌水廊道水力模型试验,建立了基于数值模拟的流量系数计算模型,求解单廊道和双廊道两种不同体型虹吸灌水廊道的流量系数。将计算得到的灌水流量值与模型试验值对比分析,验证了流量系数数值求解方法的可行性,它可为灌水廊道体型的优化和改进提供重要依据。 相似文献
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Scour depth prediction of offshore pipelines is of great significance to the design and construction of the submarine pipeline projects. In this paper, based on the CFD software package FLUENT and User Defined Function(UDF), an Eulerian two-phase model, which includes an Euler-Euler coupled model for water and sediment phases, and a turbulent model for the fluid phase, is adopted to predict the scour depth around pipelines. The model is verified by observation data obtained from laboratory experiments. On the basis of the simulations, the factors affecting the scour depth, including the effects of incipient velocity, pipe diameter and sediment particle size and so on, were investigated. Meanwhile, according to formulas of incipient velocity of various sediments, approximate calculation on theoretical scour depths is developed for pipelines of seven stations in the South China Sea, where engineering application information is available. 相似文献