排序方式： 共有48条查询结果，搜索用时 21 毫秒
1.
用流函数理论计算缓坡上波浪的破碎位置 总被引：1，自引：0，他引：1
本文通过理论计算及实验验证发现,在计算缓坡上波浪的变形、特别是确定波浪破碎点时,流函数波浪理论明显优越于线性波液理论。 相似文献
2.
1 .IntroductionOpen oceanaquacultureis becominga newfisheriesindustryasthe human demandfor seafoodin-creases .Consideringthe requirement of environmental protection,thelackof suitable shelteredsitesisforcingfishfarmers to move to more exposed offshore loc… 相似文献
3.
4.
波浪作用下三角型人工鱼礁水动力特性数值模拟与实验验证 总被引：1，自引：0，他引：1
人工鱼礁在波浪作用下水动力特性的研究对于人工鱼礁的工程安全与设计具有非常重要的意义。基于有限体积法,采用推板造波形式,通过利用VOF方法求解波面的方式建立了模拟人工鱼礁与波浪相互作用的三维数值波浪水槽。基于该数值模型研究了波浪作用下三角型镂空人工鱼礁的受力情况,并与物理模型实验结果进行比较,结果显示模拟得到的人工鱼礁受力和波浪形态均与实验结果吻合良好。根据数值模拟结果,拟合出波浪作用下人工鱼礁的水动力系数。单体三角型镂空人工鱼礁的速度力系数Cd随着Kc数、Re数的增加呈现减小的趋势;惯性力系数Cm则随着Kc数、Re数的增加呈现波动趋势。数值模拟结果显示在一个波浪周期内,人工鱼礁周围产生了较强的上升流和回流,其内部产生了明显的涡旋结构。研究结果为人工鱼礁的设计优化提供了理论依据。 相似文献
5.
The effect of biofouling on the hydrodynamic characteristics of the net cage is of particular interest as biofouled nettings can significantly reduce flow of well-oxygenated water reaching the stocked fish. For computational efficiency, the porous-media fluid model is proposed to simulate flow through the biofouled plane net and full-scale net cage. The porous coefficients of the porous-media fluid model can be determined from the quadratic-function relationship between the hydrodynamic forces on a plane net and the flow velocity using the least squares method. In this study, drag forces on and flow fields around five plane nets with different levels of biofouling are calculated by use of the proposed model. The numerical results are compared with the experimental data of Swift et al. (2006) and the effectiveness of the numerical model is presented. On that basis, flow through full-scale net cages with the same level of biofouling as the tested plane nets are modeled. The flow fields inside and around biofouled net cages are analyzed and the drag force acting on a net cage is estimated by a control volume analysis method. According to the numerical results, empirical formulas of reduction in flow velocity and load on a net cage are derived as function of drag coefficient of the corresponding biofouled netting. 相似文献
6.
7.
一、Solo分类评价法为地理高考自选模块命题献谋献策
1．Solo分类评价理论概述Solo分类评价法是由比格斯（Biggs）首先提出的,是一种以等级描述为基本特征的质性评价法,在海外有广泛的应用。Solo即可观察的学习成果结构。学生在具体知识的学习过程中,都要经历一个从量变到质变的过程,每发生一次跳跃,学生对于知识的认知就进入更高一级的阶段,可以根据学生回答问题的表现来判断他们所处的思维发展阶段,进而给予合理的评分。基于结构主义学,Solo分类法把学习成果划分为五种结构层次,如表1所示。 相似文献
8.
A three-dimensional non-hydrostatic model based on volumed-averaged, Reynolds-averaged Navier-Stokes (VARANS) equations in sigma coordinate, is applied to simulate the propagation process of irregular wave over a typical fringing coral reef profile, with emphasis on the changes of wave height and wave setup on the reef flat. Compared with the laboratory measured data of several groups of wave and water level parameters, the model is shown to be capable of simulating well the wave transformation over the reef profile with and without porous media. Across all cases, the porous cases decrease the wave height by 12% around the breaking point, and by 28% on the reef flat than the smooth cases. As for the mean water level, the results show that the maximum setdown decreases by 43% on average for the porous cases than the smooth cases, while the wave setup on the reef flat for corresponding porous and smooth simulations is found to agree with an average difference of only 6%. In addition, the variation of porosity in the range 0.47?0.87 auses little effect on the wave setup. 相似文献
9.
10.
In this paper,a numerical model for nonlinear wave propagation in currents is formulated by a set of enhanced fully nonlinear Boussinesq equations with ambient currents.This model is verified by comparison with the published results.Then the influence of currents on nonlinear focusing waves is studied by use of the numerical model.It is found that the effect of currents on the surface elevations at the focal location is negligible.Following currents can augment the maximum crest of focusing wave while decre... 相似文献