排序方式: 共有41条查询结果,搜索用时 31 毫秒
21.
Spar平台垂荡板水动力特性强迫振动试验研究 总被引:1,自引:1,他引:0
采用强迫振动试验的方法,对Spar平台不同振幅和不同振动频率下的附加质量系数和粘性阻尼系数进行了系统研究。分析研究了实心垂荡板和开孔垂荡板对Spar平台水动力特性的影响,并将Spar平台整体模型的试验结果与圆柱体和单独考虑垂荡板时的试验结果比较,结果表明垂荡板结构能有效提高Spar平台的附加质量系数和粘性阻尼系数,在KC=0.2~1.3时,开孔率为5%的开孔垂荡板Spar平台和实心垂荡板Spar平台相比,粘性阻尼有所提高但是附加质量减小。试验进一步研究了垂荡板间距对Spar平台水动力性能的影响,得到了水动力系数随垂荡板间距的变化情况,研究成果对实际工程中Spar平台的优化设计具有一定的指导意义。 相似文献
22.
对三维波浪在岛礁地形上的传播特性进行了物理模型试验研究。为了探究三维波浪在岛礁地形上传播的破碎指标,将岛礁地形简化为1∶5的向海坡与水平礁坪相连的物理模型。对于不同波况下的规则波、不规则波、多向波在该地形上的破碎特性进行了研究。结果表明,在该地形条件下,较大入射波高的波浪均在礁坪上发生破碎,并且随着入射波高的增大,破碎位置向来浪方向移动,破碎指标与入射波陡H_0/L_0相关,斜向波浪传播受入射角度的影响。同时,文中也给出了在该地形下波浪的破碎指标,并将三维结果与二维结果进行了对比。 相似文献
23.
波浪力是作用在离岸建筑物上的主要荷载,准确预测作用在结构上的波浪力在实际工程设计中极其重要,它决定着该结构是否能够安全可靠地工作。目前的研究大多集中在单向波浪作用下结构物所受的波浪力,而真实的波浪是三维多向不规则波浪。基于物理模型实验,系统地研究了多向不规则波浪作用下大尺度墩柱所受波浪力的特性。结果表明波浪的方向分布对波浪荷载具有明显的影响,尤其是对横向力,在方向分布宽度较大时,作用在墩柱上的横向力可达此时作用在墩柱上正向力的40%,这在实际工程设计中不能忽略。 相似文献
24.
风浪方向分布模式的比较 总被引:2,自引:0,他引:2
本文对目前常用的几种风浪方向分布模式进行了分析对比,进而根据由浪高仪阵列和ENDECO956测波浮标在我国各海区测得的风浪方向谱,从波能方向分布、方向累积分布、方向分布的峰值和标准差四个方面,与光易恒、Hasselmann和Donelan等分别由观测得到的经验方向分布以及文圣常等由解析方法得到的风浪方向谱进行了比较,结果表明:Donelan分布与实测结果比较一致,文圣常谱也较接近。此外,笔者在渤海由仪器阵列实测方向谱拟合得到的方向分布(改进的光易模式)与各地实测资料也比较符合。 相似文献
25.
26.
波浪在珊瑚礁地形上破碎特性试验研究 总被引:2,自引:0,他引:2
对波浪在珊瑚礁地形上的传播特性进行了物理试验研究,将珊瑚礁地形简化为坡度为1∶5的陡坡(向海坡)加较长水平礁坪段的地形,对规则波和不规则波在该地形条件下的波浪破碎及波高沿程衰减进行了研究。结果表明,波高较小时,波浪破碎发生在礁坪上,但随着入射波高的增大,破碎位置逐渐向来浪方向移动,直至在向海坡段破碎。对于在礁坪上破碎的波浪,相对水深db/L0一定的条件下,破碎波高与入射波陡H0/L0相关,且变化趋势受相对水深db/L0的影响。同时给出了该地形条件下波浪破碎指标以及礁坪段破碎后沿程波高的计算公式。 相似文献
27.
In this paper,a numerical model is developed based on the High Order Spectral(HOS) method with a non-periodic boundary.A wave maker boundary condition is introduced to simulate wave generation at the incident boundary in the HOS method.Based on the numerical model,the effects of wave parameters,such as the assumed focused amplitude,the central frequency,the frequency bandwidth,the wave amplitude distribution and the directional spreading on the surface elevation of the focused wave,the maximum generated wave crest,and the shifting of the focusing point,are numerically investigated.Especially,the effects of the wave directionality on the focused wave properties are emphasized.The numerical results show that the shifting of the focusing point and the maximum crest of the wave group are dependent on the amplitude of the focused wave,the central frequency,and the wave amplitude distribution type.The wave directionality has a definite effect on multidirectional focused waves.Generally,it can even out the difference between the simulated wave amplitude and the amplitude expected from theory and reduce the shifting of the focusing points,implying that the higher order interaction has an influence on wave focusing,especially for 2D wave.In 3D wave groups,a broader directional spreading weakens the higher nonlinear interactions. 相似文献
28.
An improved coupling of numerical and physical models for simulating 2D wave propagation is developed in this paper. In the proposed model, an unstructured finite element model (FEM) based Boussinesq equations is applied for the numerical wave simulation, and a 2D piston-type wavemaker is used for the physical wave generation. An innovative scheme combining fourth-order Lagrange interpolation and Runge-Kutta scheme is described for solving the coupling equation. A Transfer function modulation method is presented to minimize the errors induced from the hydrodynamic invalidity of the coupling model and/or the mechanical capability of the wavemaker in area where nonlinearities or dispersion predominate. The overall performance and applicability of the coupling model has been experimentally validated by accounting for both regular and irregular waves and varying bathymetry. Experimental results show that the proposed numerical scheme and transfer function modulation method are efficient for the data transfer from the numerical model to the physical model up to a deterministic level. 相似文献
29.
An improved coupling of numerical and physical models for simulating 2D wave propagation is developed in this paper. In the proposed model, an unstructured finite element model (FEM) based Boussinesq equations is applied for the numerical wave simulation, and a 2D piston-type wavemaker is used for the physical wave generation. An innovative scheme combining fourth-order Lagrange interpolation and Runge-Kutta scheme is described for solving the coupling equation. A Transfer function modulation method is presented to minimize the errors induced from the hydrodynamic invalidity of the coupling model and/or the mechanical capability of the wavemaker in area where nonlinearities or dispersion predominate. The overall performance and applicability of the coupling model has been experimentally validated by accounting for both regular and irregular waves and varying bathymetry. Experimental results show that the proposed numerical scheme and transfer function modulation method are efficient for the data transfer from the numerical model to the physical model up to a deterministic level. 相似文献
30.
海浪方向谱的现场观测与分析 总被引:3,自引:0,他引:3
方向谱是海浪的基本性质之一。本文在国内首次采用测波仪阵列法在渤海采油平台上成功地观测到海浪方向谱,给出了当地随波浪成长而变化的方向谱表达式。观测前采用数模和模型试验方法,对阵列的布置型式、测波仪间距和平台等对观测结果的影响,以及现有各种方向谱分析方法的精度等进行了对比分析,为提高观测精度,保证方向谱分析的质量提供了依据。 相似文献