MODELING ON THE CYCLIC OPERATION OF STANDING COLUMN WELLS UNDER REGIONAL GROUNDWATER FLOW

Coupled hydrogeological-thermal simulation of the Standing Column Well(SCW) system is essential to provide an optimized configuration and operation schedule for boreholes on the site.This paper presents numerical investigations and thermo-hydraulic evaluation of standing column well system operating under cyclic flow regime.A three-dimensional numerical model for groundwater flow and heat transport is used to analyze the heat exchange in the ground.The model includes the effects of convective and conductive...     

用流泵测定土的渗透系数

近年来美国的一些实验室，开始将流泵（ｆｌｏｗｐｕｍｐ）用于渗透仪，以代替传统的渗流试验装置。与达西渗透仪相比，用流泵测定土的渗透系数，不仅操作简便易行，试验时间大为节省，而且试验结果稳定可靠，精度高，试验的可重复性强。     

南水大坝渗流基流下包线的确定

大坝渗流基流是反映大坝渗流性态的重要指标之一 ,文章结合南水大坝渗流实测资料 ,采用多种模型和方法对大坝的渗流基流进行了分析 ,并根据模型分离结果推求了坝体、坝基和两岸绕坝渗漏基流下包线的表达式 ,进而分析和评价南水大坝的渗流状态。     

不稳定渗流浸润线计算在梦山水库的应用

以江西省新建县梦山水库为例,阐述了均质土坝(设计前)和砼心墙坝(设计后)的不稳定渗流浸润线计算的过程,并对计算结果进行了分析.     

NUMERICAL ANALYSIS OF SATURATED-UNSATURATED SEEPAGE FLOW IN FRACTURED ROCK MASS DUE TO SURFACE INFILTRATION

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｐａｒｔｆｒｏｍｗａｔｅｒｔａｂｌｅｔｏｇｒｏｕｎｄｓｕｒｆａｃｅｏｆ ｆｒａｃｔｕｒｅｄｒｏｃｋｍａｓｓｉｓａｎｕｎｓａｔｕｒａｔｅｄｒｅｇｉｏｎｗｈｉｃｈｉｓｎｏｔｆｕｌｌｏｆｗａｔｅｒ.Ｔｈｅｒｅｆｏｒｅ ,ｓｅｅｐａｇｅｆｌｏｗｉｎｆｒａｃｔｕｒｅｄｒｏｃｋｍａｓｓｄｕｅｔｏｓｕｒｆａｃｅｉｎｆｉｌｔｒａｔｉｏｎｉｓａｓａｔｕｒａｔｅｄ ｕｎ ｓａｔｕｒａｔｅｄｓｅｅｐａｇｅ ｐｒｏｃｅｓｓ .Ｄｕｒｉｎｇｒａｉｎｆａｌｌ (ｏｒｆｌｏｏｄｄｉｓｃｈａｒｇｉｎｇａ…     

石门拱坝右坝肩的一个特殊渗流问题

石门拱坝枢纽运行中，曾发生了右坝肩岩体内高压发电隧洞衬砌止水破坏严重渗漏事故。通过检查和对地下水监测资料的长期分析研究，证实了由于隧洞渗漏造成了整个大坝右半部坝基岩体的渗流异常。这在拱坝枢纽中很少见到。     

ANALYSIS OF TWO-PHASE FLOW PRESSURE BUILDUP DATA FROM A WELL IN AN INFINITE MULTIWELL RESERVOIR

NOMENCLATURE A1———drainage area of the tested well ( Well 1) At———total reservoir drainage area B———two-phase formation volume factor C———wellbore storage coefficient Cf———rock compressibility fator Co———oil compressibility fator Cw———water compressibility fator Ct———compressibility fator K———reservoir permeability m———slope of a semilog straight line m1———slope defined by Eq.(12) p-———average reservoir pressure-pD———di mensionless average drainag…     

ANALYSIS OF TWO-PHASE FLOW PRESSURE BUILDUP DATA FROM WELL IN AN INFINITE MULTIWELL RESERVOIR

A general method has been developed for analyzing two-phase flow pressure buildup data from a well located in a system of both production and injection wells completed in an infinite muhiwell reservoir. The analysis technique assumes that the tested well has established its own drainage area before shut-in and a linear reservoir pressure trend dominates the well pressure behavior at the instant of shut-in. And for the two-phase flow problems the horizontal saturation gradients are assumed to be negligible. The entire pressure rcsponse, whether or not conventional semilog straight lines exist, can be analyzed and the Injection-Production Ratio （IPR）, the total fluid （oil/water） mobility, the average drainage-area pressure, and also the skin factor can be calculated much easily. The validity and applicability of the method are demonstrated by a field example. The technique by using the type curves for analyzing the pressure-buildup data is also presented here.     

WELL TESTING ANALYSIS FOR HORIZONTAL WELL WITH CONSIDERATION OF THRESHOLD PRESSURE GRADIENT IN TIGHT GAS RESERVOIRS

A fundamental solution for homogeneous reservoir in infinite space is derived by using the point source function with the consideration of the threshold pressure gradient. The fundamental solution of the continuous point source function is then derived based on the Green function. Various boundary conditions of the reservoirs are considered for this case and the corresponding solutions are obtained through the mirror image reflection and the principle of superimposition. The line source solution is obtained by integration. Subsequently, the horizontal-well bottom hole pressure response function for a non-linear gas flow in the homogeneous gas reservoir is obtained, and the response curve of the dimensionless bottom hole pressure and the derivative for a horizontal well in the homogeneous gas reservoir are obtained. In the end, the sensitivities of the relevant parameters are analyzed. The well test model presented in this paper can be used as the basis of the horizontal well test analysis for tight gas reservoirs.     

COUPLING EFFECT OF SEEPAGE FLOW AND RIVER FLOW ON THE BANK FAILURE

On the basis of the generalized physical model of the riverbank, the experiments were conducted to study the mechanisms of riverbank failure under the coupling effect of seepage flow and river flow. The experimental setup was specially designed, as well as test point location, parameters and procedures, and the main influencing factors were analyzed affecting riverbank failure based on the failure types, the variations of pore water pressure and soil displacement. The results indicated that the coupling effect has different influences on the bank failure in three aspects: the failure type, the process and the extent. In addition, the river flow played a more important role than the seepage flow in the coupling effect on the bank failure.     

APPLICATION OF BODY－FITTED CURVILINEAR COORDINATE TRANSFORMATION IN 3－D SEEPAGE FLOW COMPUTATION

ＡＰＰＬＩＣＡＴＩＯＮＯＦＢＯＤＹ－ＦＩＴＴＥＤＣＵＲＶＩＬＩＮＥＡＲＣＯＯＲＤＩＮＡＴＥＴＲＡＮＳＦＯＲＭＡＴＩＯＮＩＮ３－ＤＳＥＥＰＡＧＥＦＬＯＷＣＯＭＰＵＴＡＴＩＯＮＦａｎｇＦａｎｇ－ｘｉｎ；ＱｉＬｉ；ＣｈｅｎＺｈａｏ－ｈｅ；ＰｅｎｇＹｕ（Ｓｃ...     

AN UNSTEADY SEEPAGE FLOW MODEL OF VISCO-ELASTIC POLYMER SOLUTION

With the consideration of the visco--elasticity, the adsorption effect and the variation of rheological parame ters, a seepage flow model of visco-elastic polymer solutions was established. The model was numerically treated with the finite difference method. Then curves of Bottom Hole Pressure (BHP) and formation pressure were drawn. The influences of the relaxation time, the injection rate, the permeability reduction co,efficient, the consistency coefficient and the power-law exponent of the injected fluid on pressure performance were analyzed. This study shows that it is necessary to consider the visco elasticity of non-Newtonian fluid in analyzing of pressure performance in the polymer flooding.     

APPLICATIONS OF CFD TECHNIQUE IN THE DESIGN AND FLOW ANALYSIS OF IMPLANTABLE AXIAL FLOW BLOOD PUMP

Based on established numerical methods and hydrodynamic performance testing facilities, CFD technique are applied to improve the design of the implantable axial flow blood pump and the flow analysis. (1) Applying brushless machine magnet steel, reducing its thickness while increasing the length, the flow channel's cross-section is increased, with no space connection between the large and the small rotators, and with a cone transition segment from the bearing to the principal axis, the flow is made smoother. The rotating speed is lowered by 1000 rpm – 1200 rpm under the same flow rate and pressure head, and thus the hemolysis can be avoided. (2) Different outlet stator guiding vanes are selected for the same blood pump for analyses of hydrodynamic performances and flow fields. An excellent design not only can regulate the rotating flow field into an axial one, reduce the circulation loss and improve the pump efficiency, but also can avoid backflow, vortex and secondary flow at the pump outlet, and thus the thrombus can be prevented. (3) The calf live tests show that some residual clots exist at the inner wall of the outlet connection bends, which are analyzed and explained by CFD techniques and the corresponding improvements are proposed. All results are verified by hydrodynamic performance tests and PIV flow field tests, and consistent conclusions are obtained.     

南潦闸闸基渗流安全评价有限元计算

江西省南潦闸闸基座落于不同岩层.通过采用渗流有限元法计算闸基渗流,分析了闸基不同岩性的渗流状态,研究闸基的抗渗稳定性,得出了闸基的整体渗流和抗渗稳定是安全的,右岸圩堤堤脚有可能出现渗透变形破坏的结论.     

复合土工膜防渗堆石坝渗流观测资料分析

运用统计相关、对比等分析方法，对钟吕水库大坝１９９９年和２０００年渗流观测资料进行分析，得出钟吕大坝渗流的主要特征．以进一步了解复合土工膜防渗坝的渗流状态。     

废物堆下含水层中流场数值模拟

本文用ＢＥＭ法模拟了废物堆下含水层中的流场，与传统的区域法相比，该法不仅精度高，而且不需进行区域剖分，输入数据和计算工作量少，求解的结果与实测值较吻合。     

STRUCTURES OF CONFINED VORTEX BREAKDOWN IN CONSTANT DIAMETER PIPE FLOW

Numerical solutions of three-dimensional, incompressible and unsteady Navier-Stokes equations for constant diameter swirling pipe flows are used to study vortex breakdown, including the detailed flow structures in the bubble domain and the “tail” behind the bubble during the vortex breakdown, and a comparison is made between the numerical solutions and the experimental results.     

ANALYSIS OF PULSATILE FLOW IN THE PARALLEL-PLATE FLOW CHAMBER WITH SPATIAL SHEAR STRESS GRADIENT

The Parallel-Plate Flow Chamber (PPFC), of which the height is far smaller than its own length and width, is one of the main apparatus for the in-vitro study of the mechanical behavior of cultured vascular Endothelical Cells (ECs) exposed to fluid shear stress. The steady flow in different kinds of PPFC has been extensively investigated, whereas, the pulsatile flow in the PPFC has received little attention. In consideration of the characteristics of geometrical size and pulsatile flow in the PPFC, the 3-D pulsatile flow was decomposed into a 2-D pulsatile flow in the vertical plane, and an incompressible plane potential flow in the horizontal plane. A simple method was then proposed to analyze the pulsatile flow in the PPFC with spatial shear stress gradient. On the basis of the method, the pulsatile fluid shear stresses in several reported PPFCs with spatial shear stress gradients were calculated. The results were theoretically meaningful for applying the PPFCs in-vitro, to simulate the pulsatile fluid shear stress environment, to which cultured ECs were exposed.     

FINITE ELEMENT ANALYSIS OF LAMINAR FLOW AND HEAT TRANSFER IN A BUNDLE OF CYLINDERS

In this paper two-dimensional Navier-Stokes equations and energy equation governing incompressible laminar flow past a bundle of cylinders were numerically solved by using the finite element method.The velocity correction method was used for time advancement, and spatial discretization was carried out with the Galerkin weighted residual method.Viscous flows past the cylinder banks arranged in in-line cylinder bundles and staggered cylinder bundles, coupled with heat transfer, were investigated for pitch-diameter ratios of 1.5 and 2.0 and the Reynolds numbers from 50 to 500.Flow structures and heat transfer behavior were discussed.The results obtained agree well with available numerical data.     

七一水库大坝渗流安全分析评价

对江西省玉山县七一水库自1996年1月至2003年12月的大坝渗流观测资料进行了分析,并建立了用来预报、检验测点水位和能反映大坝实际渗流性态的多因子统计模型．在此基础上结合观测资料采用有限元法反演了大坝各填筑区的渗透系数,并预测了未来高水位时大坝的渗流安全性。