Numerical Simulation of Focused Wave and Its Uncertainty Analysis
Numerical Simulation of Focused Wave and Its Uncertainty Analysis
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DOI：
10.1007/s12204-018-1970-5
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发表时间：
2018-08
影响因子：
--
通讯作者：
J. Bai;N. Ma;X. Gu
中科院分区：
文献类型：
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作者：
J. Bai;N. Ma;X. Gu
基于瞬态水波（TWW）理论，在循环水道中产生聚焦波。通过求解雷诺平均纳维-斯托克斯（RANS）方程来进行聚焦波的数值模拟。采用动态网格技术模拟造波器的运动，并采用流体体积法（VOF）捕获波浪的自由表面。仿真结果与实测数据进行了比较，得到了很好的吻合。为了定量估计数值模拟误差和不确定性，对不同位置的水面高程模拟结果采用国际拖曳水池会议（ITTC）程序推荐的不确定性分析方法。网格收敛和时间步长收敛研究都是使用三种类型的网格和时间步长进行的。验证过程中模拟结果均单调收敛，3.5、4.0、4.5m位置模拟地表高程的验证均通过与验证不确定度的比较来实现。发现收敛研究中网格和时间步长引起的数值模拟误差具有相同的数量级。此外，还对不同位置的地表高程的数值误差和不确定性进行了详细的比较和讨论。本文首次尝试进行聚焦波模拟的不确定性分析，并证明了所提出的验证和确认程序在不确定性分析中的有效性。
On the basis of the transient water wave (TWW) theory, focused wave is generated in the circulating water channel. Numerical simulation of the focused wave is carried out by solving the Reynolds averaged Navier-Stokes (RANS) equations. The dynamic grid technique is adopted to simulate the motion of the wave maker, and the volume of fluid (VOF) method is used to capture the free surface of the wave. The simulation results are compared with the measured data, and good agreement is obtained. For quantitative estimation of the numerical simulation error and uncertainty, the uncertainty analysis method recommended by the International Towing Tank Conference (ITTC) procedure is performed for the simulation results of the surface elevations at different positions. Both grid-convergence and time-step-size convergence studies are conducted using three types of grids and time step sizes. The simulation results are all monotonously convergent in the verification procedure, and the validations of the simulated surface elevations with the positions at 3.5, 4.0 and 4.5m are all achieved by comparing with the validation uncertainty. It is found that the numerical simulation errors caused by the grid and time-step-size in the convergence studies have the same order of magnitude. In addition, the numerical errors and uncertainties for the surface elevations at different positions are compared and discussed in detail. This paper presents the first attempt to carry out the uncertainty analysis of the simulation of focused wave, and the effectiveness of the proposed verification and validation procedures in the uncertainty analysis is demonstrated.