Comprehensive experimental and numerical studies have been undertaken to investigate wave energy dissipation performance and main influencing factors of a lower arc-plate breakwater. The numerical model, which conside...Comprehensive experimental and numerical studies have been undertaken to investigate wave energy dissipation performance and main influencing factors of a lower arc-plate breakwater. The numerical model, which considers nonlinear interactions between waves and the arc-plate breakwater, has been constructed by using the velocity wave- generating method, the volume of fluid (VOF) method and the finite volume method. The results show that the relative width, relative height and relative submergence of the breakwater are three main influencing factors and have significant influence on wave energy dissipation of the lower arc-plate open breakwater. The transmission coefficient is found to decrease with the increasing relative width, and the minimum transmission coefficient is 0.15 when the relative width is 0.45. The reflection coefficient is found to vary slightly with the relative width, and the maximum reflection coefficient is 0.53 when the relative width is 0.45. The transmission and reflection coefficients are shown to increase with the relative wave height for approximately 85% of the experimental tests when the relative width is 0.19 0.45. The transmission coefficients at relative submergences of 0.04, 0.02 and 0 are clearly shown to be greater than those at relative submergences of 0.02 and 0.04, while the reflection coefficient exhibits the opposite relationship. After the wave interacts with the lower arc-plate breakwater, the wave energy is mainly converted into transmission, reflection and dissipation energies. The wave attenuation performance is clearly weakened for waves with greater heights and longer periods.展开更多
本文采用电弧离子镀(Arc ion plating,AIP)和高功率脉冲磁控溅射(High power impulse magnetron sputtering,HiPIMS)复合方法,通过调控HiPIMS占空比在M2高速钢基体和单晶硅片上沉积TiZrN/TiN纳米多层膜,探究HiPIMS占空比对TiZrN/TiN纳...本文采用电弧离子镀(Arc ion plating,AIP)和高功率脉冲磁控溅射(High power impulse magnetron sputtering,HiPIMS)复合方法,通过调控HiPIMS占空比在M2高速钢基体和单晶硅片上沉积TiZrN/TiN纳米多层膜,探究HiPIMS占空比对TiZrN/TiN纳米多层膜微观结构和性能的影响规律。结果表明:随着HiPIMS占空比的增加,TiZrN/TiN纳米多层膜表面大颗粒数量呈先减少后增加趋势,同时薄膜厚度呈先减小后增大趋势。随着HiPIMS占空比从2%增加10%,TiZrN/TiN纳米多层膜择优取向从(111)晶面转变为(220)晶面,膜基结合力等级均为HF1级,硬度均在33 GPa以上,稳定摩擦因数在0.79左右。当HiPIMS占空比为2%时,TiZrN/TiN纳米多层膜的磨损率达到最小,为1.73×10^(-8) mm^(3)/(N·mm),薄膜的耐磨损性能最好。当HiPIMS占空比为6%时,TiZrN/TiN纳米多层膜的硬度和弹性模量分别增加到43.73GPa和362.98 GPa,自腐蚀电位可达到-0.39 V(vs SCE),自腐蚀电流密度为0.731μA/cm^(2),薄膜耐腐蚀性能最强,腐蚀速率较低。综合对比可知,HiPIMS占空比为6%,是TiZrN/TiN纳米多层膜制备的最佳工艺参数。展开更多
基金supported by the NSFC-Shandong Joint Fund(Grant Nos.U1706220 and U1806227)the National Natural Science Foundation of China(Grant Nos.51709140 and 51879019)the Key Laboratory of Coastal Disasters and Defence of Ministry of Education(Grant No.201703)
文摘Comprehensive experimental and numerical studies have been undertaken to investigate wave energy dissipation performance and main influencing factors of a lower arc-plate breakwater. The numerical model, which considers nonlinear interactions between waves and the arc-plate breakwater, has been constructed by using the velocity wave- generating method, the volume of fluid (VOF) method and the finite volume method. The results show that the relative width, relative height and relative submergence of the breakwater are three main influencing factors and have significant influence on wave energy dissipation of the lower arc-plate open breakwater. The transmission coefficient is found to decrease with the increasing relative width, and the minimum transmission coefficient is 0.15 when the relative width is 0.45. The reflection coefficient is found to vary slightly with the relative width, and the maximum reflection coefficient is 0.53 when the relative width is 0.45. The transmission and reflection coefficients are shown to increase with the relative wave height for approximately 85% of the experimental tests when the relative width is 0.19 0.45. The transmission coefficients at relative submergences of 0.04, 0.02 and 0 are clearly shown to be greater than those at relative submergences of 0.02 and 0.04, while the reflection coefficient exhibits the opposite relationship. After the wave interacts with the lower arc-plate breakwater, the wave energy is mainly converted into transmission, reflection and dissipation energies. The wave attenuation performance is clearly weakened for waves with greater heights and longer periods.
