固定式海洋平台利用TLD的减震研究

本文研究固定式海洋平台利用调谐液体阻尼器（ＴｕｎｅｄＬｉｑｕｉｄＤａｍｐｅｒ，简称ＴＬＤ）减小地震反应的方法。首先探讨了调谐频率比、激磁频率比对减震效果的影响，在此基础上建立了ＴＬＤ——平台系统的力学模型和运动方程，通过数值计算验证了该方法的有效性     

Freely floating-body simulation by a 2D fully nonlinear numerical wave tank

Nonlinear interactions between large waves and freely floating bodies are investigated by a 2D fully nonlinear numerical wave tank (NWT). The fully nonlinear 2D NWT is developed based on the potential theory, MEL/material-node time-marching approach, and boundary element method (BEM). A robust and stable 4th-order Runge–Kutta fully updated time-integration scheme is used with regriding (every time step) and smoothing (every five steps). A special φ_n-η type numerical beach on the free surface is developed to minimize wave reflection from end-wall and wave maker. The acceleration-potential formulation and direct mode-decomposition method are used for calculating the time derivative of velocity potential. The indirect mode-decomposition method is also independently developed for cross-checking. The present fully nonlinear simulations for a 2D freely floating barge are compared with the corresponding linear results, Nojiri and Murayama’s (Trans. West-Jpn. Soc. Nav. Archit. 51 (1975)) experimental results, and Tanizawa and Minami’s (Abstract for the 6th Symposium on Nonlinear and Free-surface Flow, 1998) fully nonlinear simulation results. It is shown that the fully nonlinear results converge to the corresponding linear results as incident wave heights decrease. A noticeable discrepancy between linear and fully nonlinear simulations is observed near the resonance area, where the second and third harmonic sway forces are even bigger than the first harmonic component causing highly nonlinear features in sway time series. The surprisingly large second harmonic heave forces in short waves are also successfully reproduced. The fully updated time-marching scheme is found to be much more robust than the frozen-coefficient method in fully nonlinear simulations with floating bodies. To compare the role of free-surface and body-surface nonlinearities, the body-nonlinear-only case with linearized free-surface condition was separately developed and simulated.     

Strength Analysis of Turret Mooring Productive/Storage Tanker

The longitudinal strength of turret mooring productive/storage tanker is studied.A numeri-cal example has been implemented according to the method presented in this paper to give practical il-lustration.From the results of the numerical example,it is concluded that the turret hole located near theforward of the amidships has small effect on the longitudinal strength of the ship hull.As for design ex-treme value of wave bending moment of storage tanker,statistic method is a more reasonablemethodology,especially with the consideration of the servere environmental conditions.The primary esti-mation of design section modulus of turret storage tanker can be determined by this design bending mo-ment.     

Fully nonlinear numerical wave tank (NWT) simulations and wave run-up prediction around 3-D structures

A finite-difference scheme and a modified marker-and-cell (MAC) algorithm have been developed to investigate the interactions of fully nonlinear waves with two- or three-dimensional structures of arbitrary shape. The Navier–Stokes (NS) and continuity equations are solved in the computational domain and the boundary values are updated at each time step by the finite-difference time-marching scheme in the framework of a rectangular coordinate system. The fully nonlinear kinematic free-surface condition is implemented by the marker-density function (MDF) technique developed for two fluid layers.To demonstrate the capability and accuracy of the present method, the numerical simulation of backstep flows with free-surface, and the numerical tests of the MDF technique with limit functions are conducted. The 3D program was then applied to nonlinear wave interactions with conical gravity platforms of circular and octagonal cross-sections. The numerical prediction of maximum wave run-up on arctic structures is compared with the prediction of the Shore Protection Manual (SPM) method and those of linear and second-order diffraction analyses based on potential theory and boundary element method (BEM). Through this comparison, the effects of non-linearity and viscosity on wave loading and run-up are discussed.     

基于RDBMS地理数据一体化存储初探

介绍了地理数据存储方法的特点，进行了一体化数据结构设计，并分别对文件形式和数据库管理地理数据在存取效率和查询速度方面进行了比较和研究，证明了地理数据一体化存储的先进性。     

青藏高原的水塔功能

青藏高原是维持我国乃至东亚地区生态系统的重要水塔。高原平均海拔在4000m以上,与周边地区形成了巨大的地势差。高原东南部不仅具有丰富的降水,而且在3500m以上以冰川雪被形态储存了巨大的水资源,因此,高原具有重要的水塔功能。基于高原潜在输出总水量和不同海拔区域水体所具有的势能两个方面,建立了高原水塔功能的模型,从而利用GIS方法,通过对我国1∶400万系列图和相关资料的统计分析,计算出高原不同高度带贮存的大气降水、冰川储水量、湖泊水量以及工农业用水量。计算结果表明,青藏高原冰川湖泊的淡水储量达39921×108m3,其中冰川储水量为39228×108m3,可利用湖泊储水量为693×108m3,平均每年由降水获得的水资源量为8495×108m3,高原工农业用水量为129×108m3。因此,高原的输出水量即出境河川径流量为6870×108m3。高原储水主要分布在海拔3000～5000m间,与高原周围相比,平均势差在2000～4000m间,最大的势差达5500m。水体具有巨大的势能,在势能的作用下,自然向周边区域输送汇集,维持着周边地区的生态过程和社会经济活动,因此,青藏高原的水塔功能对于周边地区的生态系统和社会经济系统是极其重要的。     

深部咸水层二氧化碳地质储存场地选址储盖层评价

深部咸水层CO2地质储存属于环保型工程项目,开展地质评价来确定良好的储盖层是实现CO2地质储存长期、有效、安全封存的首要前提。储层地质评价内容主要包括储层的物理性质及其注入能力等;盖层地质评价内容主要包括盖层发育特征及封闭能力等。在规划选址到工程选址的不同阶段,储盖层评价的内容和对象应根据不同阶段的目的依次提高精度和量化程度。通过国内深部咸水层CO2地质储存工程场地选址阶段划分,结合储盖层地质评价的主要内容,初步建立了储盖层适宜性评价指标及其分级标准,对国内深部咸水层CO2地质储存工程场地选址中的储盖层地质评价及适宜性评价工作具有一定的指导意义。     

水利大数据研究综述

为了推动水利大数据的发展及其在水利管理中的应用,对水利大数据相关的研究进行总结和分析,并对未来的研究方向进行展望。在回顾水利大数据的产生背景和发展历程的基础上,界定了水利大数据的概念及内涵;构建了水利大数据的研究框架,并对水利大数据的存储与共享方法、分析平台、挖掘算法、数据可视化和应用等进行了探讨。结合水利大数据研究发展和应用需求,从数据集成方法、分析挖掘算法、数据安全和综合决策分析平台等方面对水利大数据研究领域的发展趋势进行阐述。     

滨海多层含水层系统中海潮引起的地下水位波动

通过对一个滨海多层含水层系统的考察,该含水层系统由上、下弱透水层和介于中间的承压含水层组成,海底露头处被淤泥层覆盖.建立了描述该系统中地下水水头随潮汐波动的数学模型,并得到其解析解.该解析解与六个基本参数有关,分别是承压含水层的海潮传播参数,淤泥层的无量纲透水系数,上下弱透层与承压含水层贮水率的比率 (无量纲)和上下弱透层的无量纲越流.当这些参数取某些特殊值时,我们的解便化简为前人考虑的几种简单情形对应的解.分析表明,承压含水层中地下水水头波幅是上、下弱透水层贮水率和越流系数的减函数,是淤泥层相对透水系数的增函数;波动相位(时滞)是上、下弱透水层贮水率和越流系数的增函数,是淤泥层相对透水系数的减函数.     

The Solid-liquid Transformation of Low-grade Solid Potash Deposit in Dalangtan Basin and the Simplification of the Liquid Phase System

正We studied the solid-liquid transformation of low-grade solid potash deposit in Dalangtan Basin and simplified the liquid phase system.We did experiments to optimize conditions of the solid-liquid transformation.The Suitable