Numerical and experimental investigations on higher harmonics induced by multiple horizontal cylinders
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摘要: 基于势流理论采用时域高阶边界元方法建立了模拟非线性波浪与淹没水平双、三圆柱作用的数值水槽模型,其中采用混合欧拉-拉格朗日方法更新自由水面,四阶Runga-Kutta方法进行时间步进。利用两点法分离得到潜体下游高阶自由波,进而研究潜体间距、布置形式等对高倍频自由波的影响。同时在物理水槽内开展多潜体高阶谐波物理模型试验,并将试验结果与数值结果进行对比,吻合较好。研究发现:淹没双圆柱下游高阶谐波幅值随潜体间距呈现周期性振荡变化,其振荡的重现距离约为波长一半。而淹没三圆柱下游的高阶谐波随第一个间距呈周期性振荡变化,随第二个间距的增大而减小。Abstract: Based on potential flow theory, a numerical wave flume was founded to model the interaction of nonlinear waves and dual or triple submerged horizontal cylinders by using a time-domain higher-order boundary element method. The mixed Eulerian-Lagrangian technique was used for the refresh of free surface, and the 4th-order Runga-Kutta scheme was adopted for the time advance. The two-point method was adopted to separate the higher free harmonics from the downstream waves. Then the effects of interval of submerged objects and distribution scheme on the higher free harmonics were investigated. Meanwhile, physical tests were carried out for higher harmonics induced by multiple submerged objects in a wave flume. Good agreements between the numerical results and experimental data were obtained. It was found that higher free harmonic amplitude oscillates periodically with the variation of the interval in the dual cylinder system. And the reoccurrence interval is near to half wave length. In the triple cylinder system, higher free harmonics amplitude oscillates periodically with the first interval but decreases with the second interval.
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Patarapanich M. Maximum and zero reflection from submerged plate[J]. Journal of Waterway, Port, Coastal, and Ocean Engineering,1984, 2:171-181. Dick T M, Brebner A. Solid and permeable submerged breakwaters[C]//Proc. 11th Coastal Eng. Conf., London, 1968, 72, 1141-1158. Grue J. Nonlinear water waves at a submerged obstacle or bottom topography[J]. Journal of Fluid Mechanics, 1992, 244:455-476. Brossard J, Perret G, Blonce L, et al. A Higher harmonics induced by a submerged horizontal plate and a submerged rectangular step in a wave flume[J]. Coastal Engineering, 2009, 56(1):11-22. Ohyama T, Nadaoka K. Transformation of nonlinear wave train passing over a submerged shelf without breaking[J].Coastal Engineering, 1994, 24(1/2):1-22. 郑永红, 沈永明, 吴修广, 等. 用改进的Boussinesq方程模拟潜堤上的波浪变形[J]. 中国工程科学, 2004, 6(4):34-40. Zheng Yonghong, Shen Yongming, Wu Xiuguang,et al. Simulation of wave propagation over a submerged bar using a modified boussinesq equation[J]. Engineering Science, 2004, 6(4):34-40. 张洪生, 冯文静, 商辉. 非线性波传播的新型数值模拟模型及其试验验证——引入变换速度变量[J]. 海洋学报, 2007, 29(5):161-173. Zhang Hongsheng, Feng Wenjing, Shang Hui. A new approach to numerical simulation of nonlinear wave propagation and its experimental verification[J]. Haiyang Xuebao, 2007, 29(5):161-173. Luth H R, Klopman G, Kitou N. Kinematics of waves breaking partially on an offshore bar; LDV measurements of waves with and without a net onshore current[R]. Report H-1573, Delft Hydraulics, 1994:40. 陈丽芬, 宁德志, 滕斌, 等. 潜堤后高阶自由谐波的研究[J]. 海洋学报, 2011, 33(6):165-172. Chen Lifen, Ning Dezhi, Teng Bin, et al. Study on the higher free harmonic waves on the lee side of a submerged bar[J]. Haiyang Xuebao, 2011, 33(6):165-172. Ning Dezhi, Lin Hongxing, Teng Bin, et al. Higher harmonics induced by waves propagating over a submerged obstacle in the presence of uniform current[J]. China Ocean Engineering, 2014, 28(6):725-738. 陈丽芬, 宁德志, 滕斌, 等. 潜堤上波流传播的完全非线性数值模拟[J]. 力学学报,2011, 43(5):834-843. Chen Lifen, Ning Dezhi, Teng Bin, et al. Fully nonlinear numerical simulation for wave-current propagation over a submerged bar[J]. Chinese Journal of Theoretical and Applied Mechanics, 2011, 43(5):834-843. 周斌珍, 宁德志, 滕斌. 造波板运动造波实时模拟[J]. 水动力学研究与进展, 2009, 24(4):1-12. Zhou Binzhen, Ning Dezhi, Teng Bin. Real-time simulation of waves generated by a wave maker[J]. Chinese Journal of Hydrodynamics, 2009, 24(4):1-12. Ting F C K, Kim Y K. Vortex generation in water waves propagating over a submerged obstacle[J]. Coastal Engineering, 1994, 24(1/2):23-49. Liu C R, Huang Z H, Keat Tan S. Nonlinear scattering of non-breaking waves by a submerged horizontal plate:Experiments and simulations[J]. Ocean Engineering, 2009, 36:1332-1345.
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