Efficient computation method for two-dimensional nonlinear waves

I~IOWNUmerics wave tank is a ~ tOOl by which variouS nonlinear wave - ac interactionpwhleln can be treated in time domain. As the face stage, we f~ our efforts on the devious of an effita saution tee~ of fully nofor waves. aam numtried of water - wavesconnected PwhlemS, es~ in a wave tank, is alwayS comas Of PartS: wave generation, P~ and a~. The effi~ Of a nUm~ wave tankdepends not Only on the qwhty Of the wave abotion tecboaue, which allowS the lOng times~ and keePS finite tank leng…     

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

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。     

必须重视大型石油储罐的抗震问题

地震灾害是各种自然灾害中最大的一种灾害，而大型石油储罐则是石油化工设备中震害最大设备，因此必须重视大型油罐的抗震问题，本文从油罐的几何形状的荷载特征等方面说明了油罐震害之所以特别大的主要原因；指出了油罐的主要震害；并从四个方面说明了油罐的抗震理论是非常复杂的。     

Wavelet‐based non‐stationary seismic rocking response of flexibly supported tanks

The non‐stationary rocking response of liquid storage tanks under seismic base excitations including soil interaction has been developed based on the wavelet domain random vibration theory. The ground motion has been characterized through statistical functionals of wavelet coefficients of the ground acceleration history. The tank–liquid–foundation system is modelled as a multi‐degree‐of‐freedom (MDOF) system with both lateral and rocking motions of vibration of the foundation. The impulsive and convective modes of vibration of the liquid in the tank have been considered. The wavelet domain coupled dynamic equations are formulated and then solved to get the expressions of instantaneous power spectral density function (PSDF) in terms of functionals of input wavelet coefficients. The moments of the instantaneous PSDF are used to obtain the stochastic responses of the tank in the form of coefficients of hydrodynamic pressure, base shear and overturning base moment for the largest expected peak responses. Parametric variations are carried out to study the effects of various governing parameters like height of liquid in the tank, height–radius ratio of the tank, ratio of total liquid mass to mass of foundation, and shear wave velocity in the soil medium, on the responses of the tank. Copyright © 2003 John Wiley & Sons, Ltd.     

立式钢制储罐基于地震损伤性能的抗震设计方法

针对立式钢制储罐在强烈地震作用下会产生不同程度的损伤的特点，遵循抗震设计规范的“小震不坏，中震可修，大震不倒”的抗震设计原则，结合三水准烈度，提出了储罐的地震损伤性能目标，并给出了基于地震损伤性能的抗震设计方法。所提出抗震设计方法，更加准确地考虑了储罐的提离问题。     

Model tank electrical resistivity characterization of LNAPL migration in a clayey-sand formation

A modeling tank time-lapse 2D electrical resistivity experiment was undertaken to model the leakage of petroleum products from underground pipelines into a clayey-sand aquifer. Numerical modeling was employed to simulate the electrode arrays that would resolve the post-leakage subsurface image most efficiently. Of the four arrays tested, the dipole–dipole array proved most effective and was adopted for the laboratory studies. Pre-injection surveys were conducted to assist in discriminating between features caused by hydrocarbon accumulation and those due to natural geologic variability. Subsequently, controlled injection of diesel–oil into the model tank was undertaken at regular intervals over a period of 3 days. Experimental evidence obtained from the studies indicates that high resistivity build up few hours after injection is directly related to hydrocarbon accumulation. Rather than biodegradation of the hydrocarbon, a more probable explanation for the observed decrease in resistivity observed a few hours after injection is simply that the hydrocarbons drained to a deeper level after pooling temporarily at a shallow level.     

水槽模拟试验及其在过山气流研究中的应用

中条山有色金属公司铜冶炼厂改扩建工程地处中条山财侧。烟羽的扩散易受地形的影响。为了解工程在现有条件下，烟羽的排放情况和过山气流的拢动情况，在相似准则的基础上，进行了水槽模拟试验，得出了不同风速情况下的试验结果，为拟建工程厂址的选择提供了重要依据。     

C/B法城镇污水处理技术简介

目前我国城市污水处理普遍采用的工艺为普通活性污泥法、氧法沟法、SBR法及AB法等。这些工艺虽然运行稳定，达到可靠，但投资大、运行费用高。鉴于我国的经济发展水平与发达国家有较大的差距，污染治理的资金投入有限，提出必须研究适合我国国情的高效、低耗、低成本的城市污水处理技术。阐述了C/B法的C段和B段污水处理技术，指出由于该技术是化学强化处理技术与生物滤池技术的有机结合，综合了化学处理与生物处理技术的优点，具有可分阶段实施、投资省、运行费用低、占地少、有效去除磷、氨、氮等优点。     

立式储罐与地基相互作用地震反应分析

在考虑地基与储罐相互作用的情况下,采用有限元法对储罐住水平地震荷载作用下的反应进行了计算。推导了系统刚度矩阵及质量矩阵的计算过程。通过对四种场地条件下的地震响应分析,得出了储罐各种参数对地震反应的影响。分析表明：不同的地震激励对储罐系统的反应是不同的;地基刚度对系统的动力响应的影响也很大：即地基越“柔”,基底弯矩、罐壁轴向应力越小,但环向应力和底板变形却在增加。