波流作用下悬浮隧道的涡激动力响应

将单跨悬浮隧道简化成简支梁,利用梁的弯曲振动方程,在考虑结构粘性阻尼和非线性流体阻尼的条件下,采用伽辽金法和数值积分法,对悬浮隧道在波流作用下的涡激动力响应进行了计算,分析了隧道断面形式、尺寸及放置深度对悬浮隧道涡激谐振的影响。     

波浪潮流作用下的悬沙输移

本文提出了波浪潮流作用下悬沙输移的二维数值模拟,并讨论了模型中的几个重要参数,模拟结果与天津港区现场情况很吻合。     

Study of algorithms of new slender ship theory of wave resistance

In this paper, Noblesse‘s New Slender-Ship Wave-Making Theory was investigated numerically. Detailed expressions of zeroth and 1st order wave resistance have been derived and calculation programs have also been compiled. In the single and double integral terms of Green function, the kernel function of wave resistance expression, special function expansion method and Chebyshev polynomials approach have been adopted respectively, which greatly simplify the calculation and increase the convergence speed.     

一种补偿海水声速的新方法

在影响多普勒计程仪测速精度的多种因素中,以声速的影响为最大。多普勒计程仪的高精度必须建立在良好的声速补偿措施上,本文就双波束工作方式的多普勒计程仪从原理上分析声速变化对测速精度的影响,并介绍了一种新的补偿声速的方法:声学透镜法,它能在换能器自身结构得以完善的同时补偿声速,保证系统的测速精度。     

S-175集装箱船舶波浪载荷的船模试验与线性切片理论计算的比较

本文就日本S-175集装箱船舶的波浪载荷进行了船模试验与线性切片理论计算的比较,发现线性切片理论对于波浪载荷沿船长的纵向分布以及中拱与中垂的不同分量都与试验值存在着相当大的差异,仅纵向运动较为满意;揭示了对于在高浪级下快速舰船的波浪载荷,特别是砰击载荷应致力于开展非线性理论和试验研究。     

Slow drift damping force acting on a horizontal cylinder

The hydrodynamic forces acting on a circular cylinder and a rectangular cylinder undergoing slow drift oscillation in regular waves were investigated experimentally and numerically. Forced oscillation tests with low frequency and large amplitude in regular waves and forced two-harmonic oscillation with combined low and high frequencies were carried out in the experimental study. In the numerical study a finite-difference method was used to simulate viscous flow around a two-dimensional oscillating cylinder. The results of experiments showed that a horizontal rectangular cylinder oscillating slowly in waves has much higher damping coefficients than one oscillating in two-harmonic mode, while the numerical study indicated that such differences in the damping coefficient arise partly from the different effects of one-direction harmonic flow and rotating flow on the vortex shedding caused by the slow drift oscillation.     

蛇形造波机性能测试

对蛇形造波机的机械性能和造波质量进行了测试。所有指标均满足试验要求。规则波最大波高达35cm。多方向不规则波的有效范围达到理论长度。     

Effects of wave directionality and choice of wave spectrum on the extreme response of a deep water jacket

Wave-induced load effects in an idealized deep water jacket are considered. The structure is selected more to examine the worst effects of wave-induced uncertainties than to represent a realistic North Sea installation. The largest natural period is about 5 9 s and the structural response is significantly affected by dynamics. The structural system is linearized and response extremes are predicted by means of a stochastic, dynamic long term response analysis. A realistic modelling of ocean waves for long term response calculations is outlined. Various possibilities concerning the choice of wave spectrum are included and the corresponding effects on the predicted extremes are demonstrated. A sensitivity study is carried out both for the quasi-static response and for the resulting dynamic response. Finally, the effects of accounting for wave directionality are indicated. This includes both the introduction of a varying main wave direction and the modelling of the shortcrestedness for a given sea state.     

交流传动电力机车网侧谐波分析与对策

就交流传动电力机车网侧谐波进行了较为详细的分析,根据不同系统的特点及其影响提出应采取的措施和建议,为电力机车总体及其主电路重大部件的设计,以及供电系统相关参数的选择,提供了参考。     

波生近岸流的数学模型研究

在理论上和数值技术上对已有的基于辐射应力理论的波生近岸流数学模型进行了改进,(1)使用考虑非线性作用的多向不规则波联合折射绕射数学模型确定波浪场,以期波场计算更加准确;(2)根据Dally等的研究成果,在波生流运动方程中加入破波切应力作用项,在辐射应力公式中加入了卷破波和波动Stokes漂流(Stokes drift)造成的向岸质量通量项,以期在破碎带内运动方程和辐射应力更为合理;(3)建立了基于两种网格的两套数学模型,即三角形网格有限差分数学模型和矩形网格有限差分数学模型,基于这两种网格的数学模型能满足近岸波生流场的模拟需要。就一模型海区对该文的模型进行了应用。