Experimental Studies on Burial of Finite-Length Cylinders under Oscillatory Flow
Experimental Studies on Burial of Finite-Length Cylinders under Oscillatory Flow
复制标题
DOI：
10.1061/(asce)0733-950x(2007)133:2(117
复制
发表时间：
2007-03
期刊：
影响因子：
--
通讯作者：
S. T. Demir;Marcelo H. García
中科院分区：
文献类型：
--
作者：
S. T. Demir;Marcelo H. García
利用大型振荡水沙洞(LOWST)对有限长圆柱体在纯振荡流作用下的自埋进行了研究。圆柱形模型被放置在60厘米深的沙床上，并在摄像机的帮助下进行了圆柱形埋藏的测量。在广泛的流动条件下完成了30个实验，以调查长径比在2到4之间的圆柱体的冲刷造成的埋藏。实验结果表明，屏蔽参数与平衡埋深之间存在很强的相关性。另一方面，平衡埋深与通常用于确定管道平衡冲刷深度的Keulegan-Carpenter数之间的相关性，对于目前的短圆筒情况，被发现没有那么强。模型的长径比、密度和初始埋深对平衡埋深没有影响。确定了开始埋葬所需的时间间隔。还确定了圆柱形物体埋葬的时间尺度，并用半经验方程进行了表征。在此基础上，提出了一个新的有限长圆柱体埋深估算公式，并提出了一种估算埋藏过程的方法。
Self-burial of finite-length cylinders under pure oscillatory flow was studied with a large oscillating water-sediment tunnel (LOWST). Cylindrical models were placed on a 60 cm deep sandy bed and measurements of cylinder burial were made with the aid of video cameras. Thirty experiments were completed for a wide range of flow conditions to investigate burial due to scour of cylinders having length-to-diameter ratios between two and four. Experimental results showed a strong correlation between the Shields parameter and the equilibrium burial depth. On the other hand, the correlation between the equilibrium burial depth and the Keulegan-Carpenter number, commonly used to determine equilibrium scour depth of pipelines, was found to be less strong for the current case of short cylinders. Length-to-diameter ratio, density, and initial burial of the models were not found to influence the equilibrium burial depth. A time interval, necessary for burial initiation, was defined. The time scale for the burial of a cylindrical object was also identified and characterized by a semiempirical equation. Based on the observations, a new equation to estimate the burial of finite-length cylinders is advanced and a procedure to estimate the burial process is proposed.