FINITE ELEMENT ANALYSIS FOR THE UNSTEADY NEARSHORE CIRCULATION DUE TO WAVE－CURRENT INTERACTION（II）──TWO－STEP EXPLICIT FINITE ELEMENT METHOD

ＦＩＮＩＴＥＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＦＯＲＴＨＥＵＮＳＴＥＡＤＹＮＥＡＲＳＨＯＲＥＣＩＲＣＵＬＡＴＩＯＮＤＵＥＴＯＷＡＶＥ－ＣＵＲＲＥＮＴＩＮＴＥＲＡＣＴＩＯＮ（ＩＩ）──ＴＷＯ－ＳＴＥＰＥＸＰＬＩＣＩＴＦＩＮＩＴＥＥＬＥＭＥＮＴＭＥＴＨＯＤＷ...     

STRESS－STBAIN FIELD NEAR CRACK TIP AND CALCULATION OF CRITICAL STRESS OF CRACK PROPAGATION IN A PURE BENDING BEAM OF RECTANGULAR SECTION WITH ONE－SIDED MODEICRACK

ＳＴＲＥＳＳ－ＳＴＢＡＩＮＦＩＥＬＤＮＥＡＲＣＲＡＣＫＴＩＰＡＮＤＣＡＬＣＵＬＡＴＩＯＮＯＦＣＲＩＴＩＣＡＬＳＴＲＥＳＳＯＦＣＲＡＣＫＰＲＯＰＡＧＡＴＩＯＮＩＮＡＰＵＲＥＢＥＮＤＩＮＧＢＥＡＭＯＦＲＥＣＴＡＮＧＵＬＡＲＳＥＣＴＩＯＮＷＩＴＨＯＮＥ－Ｓ...     

FINITE ELEMENTAN ALYSIS FOR THE UNSTEADY NEARSHORECIR CULATION DUE TO WAVE－CURRENT INTER－ACTION（I）──NUMERICAL MODEL

ＦＩＮＩＴＥＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＦＯＲＴＨＥＵＮＳＴＥＡＤＹＮＥＡＲＳＨＯＲＥＣＩＲＣＵＬＡＴＩＯＮＤＵＥＴＯＷＡＶＥ－ＣＵＲＲＥＮＴＩＮＴＥＲ－ＡＣＴＩＯＮ（Ｉ）——ＮＵＭＥＲＩＣＡＬＭＯＤＥＬＷｕＷｅｉ－ｘｉｏｎｇ（吴伟雄）（Ｔｏｎｇｊ...     

ACTUATION OF SLOSHING MODULATED FORCE AND MOMENT ON LIQUID CONTAINER DRIVEN BY JITTER ACCELERATIONS ASSOCIATED WITH SIEW MOTION IN MICROGRAVITY

ＡＣＴＵＡＴＩＯＮＯＦＳＬＯＳＨＩＮＧＭＯＤＵＬＡＴＥＤＦＯＲＣＥＡＮＤＭＯＭＥＮＴＯＮＬＩＱＵＩＤＣＯＮＴＡＩＮＥＲＤＲＩＶＥＮＢＹＪＩＴＴＥＲＡＣＣＥＬＥＲＡＴＩＯＮＳＡＳＳＯＣＩＡＴＥＤＷＩＴＨＳＩＥＷＭＯＴＩＯＮＩＮＭＩＣＲＯＧＲＡＶＩＴＹＲ...     

EXACT SOLUTIONS OF NEAR CRACK LINE FIELDS FOR MODE I CRACK UNDER PLANE STRESS CONDITION IN AN ELASTIC－PERFECTLY PLASTIC SOLID

ＥＸＡＣＴＳＯＬＵＴＩＯＮＳＯＦＮＥＡＲＣＲＡＣＫＬＩＮＥＦＩＥＬＤＳＦＯＲＭＯＤＥＩＣＲＡＣＫＵＮＤＥＲＰＬＡＮＥＳＴＲＥＳＳＣＯＮＤＩＴＩＯＮＩＮＡＮＥＬＡＳＴＩＣ－ＰＥＲＦＥＣＴＬＹＰＬＡＳＴＩＣＳＯＬＩＤＥＸＡＣＴＳＯＬＵＴＩＯＮＳＯＦＮＥＡ...     

Iterative algorithms for finding approximate solutions of completely generalized strongly nonlinear quasivariational inequalities

ＩＴＥＲＡＴＩＶＥＡＬＧＯＲＩＴＨＭＳＦＯＲＦＩＮＤＩＮＧＡＰＰＲＯＸＩＭＡＴＥＳＯＬＵＴＩＯＮＳＯＦＣＯＭＰＬＥＴＥＬＹＧＥＮＥＲＡＬＩＺＥＤＳＴＲＯＮＧＬＹＮＯＮＬＩＮＥＡＲＱＵＡＳＩＶＡＲＩＡＴＩＯＮＡＬＩＮＥＱＵＡＬＩＴＩＥＳＺｅｎｇＬｕ－ｃ...     

Iterative construction of fixed points for multivalued operators of the monotone type in uniformly smooth Banach spaces

ＩＴＥＲＡＴＩＶＥＣＯＮＳＴＲＵＣＴＩＯＮＯＦＦＩＸＥＤＰＯＩＮＴＳＦＯＲＭＵＬＴＩＶＡＬＵＥＤＯＰＥＲＡＴＯＲＳＯＦＴＨＥＭＯＮＯＴＯＮＥＴＹＰＥＩＮＵＮＩＦＯＲＭＬＹＳＭＯＯＴＨＢＡＮＡＣＨＳＰＡＣＥＳＤｅｎｇＬｅｉ（邓磊）（ＣｈｏｎｇｑｉｎｇＴ...     

ON THE BOUNDEDNESS AND THE STABILITY RESULTS FOR THE SOLUTION OF CERTAIN FOURTH ORDER DIFFERENTIAL EQUATIONS VIA THE INTRINSIC METHOD

ＯＮＴＨＥＢＯＵＮＤＥＤＮＥＳＳＡＮＤＴＨＥＳＴＡＢＩＬＩＴＹＲＥＳＵＬＴＳＦＯＲＴＨＥＳＯＬＵＴＩＯＮＯＦＣＥＲＴＡＩＮＦＯＵＲＴＨＯＲＤＥＲＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＶＩＡＴＨＥＩＮＴＲＩＮＳＩＣＭＥＴＨＯＤＣｅｍｉｌＴＵＮＣ;Ａ...     

Numerical modeling of the initial stage of the generation of unsteady vortices from sharp corner in plane compressible flow

ＮＵＭＥＲＩＣＡＬＭＯＤＥＬＩＮＧＯＦＴＨＥＩＮＩＴＩＡＬＳＴＡＧＥＯＦＴＨＥＧＥＮＥＲＡＴＩＯＮＯＦＵＮＳＴＥＡＤＹＶＯＲＴＩＣＥＳＦＲＯＭＳＨＡＲＰＣＯＲＮＥＲＩＮＰＬＡＮＥＣＯＭＰＲＥＳＳＩＢＬＥＦＬＯＷＨｕａｎｇＤｕｎ（黄敦）（Ｄｅｐａｒｔ．...     

RUDIMENTAL EQUATIONS FOR THERMO－ELASTO－PLASTIC STRESS ANALYSIS DURING CONTINUOUS CASTING WITH PHASE CHANGE

ＲＵＤＩＭＥＮＴＡＬＥＱＵＡＴＩＯＮＳＦＯＲＴＨＥＲＭＯ－ＥＬＡＳＴＯ－ＰＬＡＳＴＩＣＳＴＲＥＳＳＡＮＡＬＹＳＩＳＤＵＲＩＮＧＣＯＮＴＩＮＵＯＵＳＣＡＳＴＩＮＧＷＩＴＨＰＨＡＳＥＣＨＡＮＧＥＺｈａｏＸｉｎｇ－ｈｕａ（赵兴华）;ＣｈｅｎｇＸｉａｏ－ｄｉ...     

A modification of Taylor-Galerkin Finite Element Method and its application

Two basic hypothesises of Taylor-Galerkin Finite Element Method are studied in this paper.One of them which is unreasonable is redefined.The only hypothesis becomes the standpoint of Generalized Finite Element.We use this idea to analysis stream function-vorticity equations with Modified Taylor-Galerkin Finite Element Method,and give the two-step solving method,which makes the solving process more reasonable than ever before.Several computational examples reveal that the results of this new method are satisfied.     

Tensor Universal Serendipity Elements and unsteady Taylor-Galerkin finite element method

A new kind of Universal Serendipity Element (USE)— the Tensor Universal Serendipity Element (TUSE) is constructed by using both tensor force finite elements and the basic idea of USE. The formulation of shape functions and their derivatives for TUSE is presented. TUSE can be used to study steady and unsteady transonic flow fields when combined with Taylor-Galerkin Finite Element Methods, the NND scheme in FDM, and four-stage Runge-Kutta methods. As numerical examples the transonic flow in cascades and one kind of complex unsteady transonic axisymmetric flow in engineering are studied. It is shown that the algorithm presented in this paper is efficient and robust. The project supported by the National Natural Science Foundation of China     

叶轮机内部流场的修正Taylor—Galerkin（MDTGFE）有限元法

首先改进了ＴＧＦＥ的基本假设考虑前后时间步之间的非线性效应，对流函数－涡量方程进行有限元离散，得到了修正Ｔａｙｌｏｒ－Ｇａｌｅｒｋｉｎ算法的有限元离散公式。采用这种方法，我们计算了后台阶绕流流动。另外，还用本方法的思想计算了叶轮机内部准三元流动。     

Comparison of finite element methods for the St. Venant equations

Finite element schemes for hyperbolic systems are applied to the St. Venant equations for one-dimensional, unsteady, open channel flow. The comparative performances of the characteristic-dissipative-Galerkin, Taylor-Galerkin and least squares finite element schemes are assessed by means of linear Fourier analysis and solution of idealized non-linear wave propagation problems. Of particular interest is the behaviour of these schemes for the regressive wave component in both subcritical and supercritical flows. To assess the quality of the basic solution, the methods are compared without any additional artificial diffusion or shock-capturing formulations. The balanced treatment of both wave components in the characteristic-dissipative-Galerkin method is illustrated. Also, the method displays little sensitivity to parameters variations. The Taylor-Galerkin scheme provides good solutions, although oscillations due to wave dispersion and minimal diffusion of the regressive wave are displayed. Also, this method is somewhat sensitive to the time step increment. The least squares method is considered unsuitable for unsteady, open channel flow problems owing to its inability to propagate a regressive wave in a supercritical flow.     

Modeling and Numerical Simulations of Immiscible Compressible Two-Phase Flow in Porous Media by the Concept of Global Pressure

A new formulation is presented for the modeling of immiscible compressible two-phase flow in porous media taking into account gravity, capillary effects, and heterogeneity. The formulation is intended for the numerical simulation of multidimensional flows and is fully equivalent to the original equations, contrary to the one introduced in Chavent and Jaffré (Mathematical Models and Finite Elements for Reservoir Simulation, 1986). The main feature of this formulation is the introduction of a global pressure. The resulting equations are written in a fractional flow formulation and lead to a coupled system which consists of a nonlinear parabolic (the global pressure equation) and a nonlinear diffusion–convection one (the saturation equation) which can be efficiently solved numerically. A finite volume method is used to solve the global pressure equation and the saturation equation for the water and gas phase in the context of gas migration through engineered and geological barriers for a deep repository for radioactive waste. Numerical results for the one-dimensional problem are presented. The accuracy of the fully equivalent fractional flow model is demonstrated through comparison with the simplified model already developed in Chavent and Jaffré (Mathematical Models and Finite Elements for Reservoir Simulation, 1986).     

Anisotropic multistage finite element method for two dimensional viscous transonic flow in turbomachinery

A new method based on the anisotropic tensor force finite element and Taylor-Galerkin finite element is presented in the present paper. Its application to two-dimensional viscous transonic flow in turbomachinery improves the convergence rate and stability of calculation, and the results obtained agree well with the experimental measurements.     

A Taylor-Galerkin Method for Modeling Unsteady Fluid Flow Under its Own Weight

The free fluid-surface of incompressible creeping flows is analyzed using a finite element method. A pseudo-concentration (PC) function is introduced to determine the position of the free surface. The Taylor-Galerkin finite element method (TGFEM) is applied to solve the equation of the PC function. Nine-node quadratic interpolation is used for both PC and velocity. The unsteady flows of fluids moving of their own weight are analyzed using the proposed method.     

Effective permeability of cracked unsaturated porous materials

This study focuses on a theoretical estimation of the effective permeability of unsaturated cracked porous media. The closed-form flow solution around and in a superconductive crack, embedded in an infinite porous matrix under a far-field condition, is recalled first. Then the solution of flow around a completely unsaturated (empty) crack that is considered as an obstruction against the flow is determined. The flow solution for partially saturated crack in special configurations is obtained by superposition of the two basic solutions for superconductive and empty cracks. The contribution of an unsaturated crack, with a given saturation degree, to the effective permeability is estimated by using dilute upscaling scheme. Numerical results obtained by Finite Elements Method, are in good agreement with the theoretical results for weak crack densities but show the additional effect of cracks interaction for higher densities.     

透平叶栅跨音速流动计算中的新型有限元法

将Ｔａｙｌｏｒ－Ｇａｌｅｒｋｉｎ有限元法和多级有限元的思想结合起来，构成了在收敛速度和稳定性两方面均较好的新型有限元算法：多级广义有限元。利用这一方法，分别基于Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程和Ｅｕｌｅｒ方程，研究了透平跨音速叶栅无粘流动和粘性流动，并将计算结果与实验结果作了比较。计算结果表明，本方法是透平机械内部跨音速流动计算的强有力的手段。     

注塑成型充填／后充填过程统一的可压缩流动分析

注塑成型是重要的塑料成型工艺,成型过程中熔体在模腔中的流动和传热对最终制品的性能和质量有重要的影响,因此,精确预测注塑过程的流动及传热历史,并进一步预测注塑制品的收缩、翘曲和机械性能等性能和质量指标具有重要意义。为了精确地描述成型过程中材料的流动及传热行为,本文针对注塑成型过程的工艺特点,将充填后充填过程作为一个统一的过程,考虑材料可压缩性及相变对充填和后充填过程的影响,建立了充填后充填过程的统一数学模型。采用有限元/有限差分/控制体积混合数值方法,实现了注塑成型充填后充填一体化模拟。数值模拟结果与实验结果的对比,验证了本文模型和算法。