A CLASS OF ALTERNATING GROUP METHOD OF BURGERS' EQUATION

IntroductionWeconsiderthefollowingnonlinearBurgers’equation : u t u u x=ε 2 u x2 ,　　 0 0 ,( 1 )withtheinitialandtheboundaryconditions　　　　　u(x,0 ) =f(x) ,　　 0 相似文献   

A CLASS OF ALTERNATING GROUP METHODOF BURGERS＇ EQUATION

Some new Saul‘ yev type asymmetric difference schemes for Burgers’ equation isgiven, by the use of the schemes, a kind of alternating group four points method for solvingnonlinear Burgers‘ equation is constructed here. The basic idea of the method is that thegrid points on the same time level is divided into a number of groups, the differenceequations of each group can be solved independently, hence the method with intrinsicparallelism can be used directly on parallel computer. The method is unconditionally stableby analysis of linearization procedure. The numerical experiments show that the method has good stability and accuracy.     

A new alternating group explicit-implicit algorithm with high accuracy for dispersive equation

In this paper, a new alternating group explicit-implicit （nAGEI） scheme for dispersive equations with a periodic boundary condition is derived. This new unconditionally stable scheme has a fourth-order truncation error in space and a convergence ratio faster than some known alternating methods such as ASEI and AGE. Comparison in accuracy with the AGEI and AGE methods is presented in the numerical experiment.     

The alternating segment crank-nicolson method for solving convection-diffusion equation with variable coefficient

IntroductionThenumericalmethodsforsolvingtheconvection_diffusionequationwithvariablecoefficientisappliedwidelyintheproblemsofconductionofheatininhomogeneousmediumandionicdiffusion .Forexample ,thetransmissionofthepaleoheatoftheearth’sinterioronthenumericalsimulationforevolutionaryhistoryofbasinisoneoftheseproblems,hencethestudyoftheparallelnumericalmethodoftheproblemanditsapplicationisveryimportantforthedevelopmentofmodernscienceandtechnology .D .J.EvansandZhangBao_linetal.haveobtainedmanyr…     

Alternating segment explicit-implicit scheme for nonlinear third-order KdV equation

A group of asymmetric difference schemes to approach the Korteweg-de Vries(KdV)equation is given here.According to such schemes,the full explicit difference scheme and the fun implicit one,an alternating segment explicit-implicit difference scheme for solving the KdV equation is constructed.The scheme is linear unconditionally stable by the analysis of linearization procedure,and is used directly on the parallel computer. The numerical experiments show that the method has high accuracy.     

ON THE NUMERICAL SOLUTION OF QUASILINEAR WAVE EQUATION WITH STRONG DISSIPATIVE TERM

The numerical solution for a type of quasilinear wave equation is studied. The three-level difference scheme for quasi-linear waver equation with strong dissipative term is constructed and the convergence is proved. The error of the difference solution is estimated. The theoretical results are controlled on a numerical example.     

Four-point explicit difference schemes for the dispersive equation

A class of three-level explicit difference schemes for the dispersive equationu_1=au_(xxx)are established These schemes have higher stability and involve four meshpoints at the middle level.Their local truncation errors are O(τ+h)and stabilityconditions are from|R|≤0.25 to|R|≤10,where|R|=|a|τ/h~3,which is muchbetter than|R|≤0.25.     

The numerical solution of a singularly perturbed problem for quasilinear parabolic differential equation

We consider the numerical solution of a singularly perturbed problem for the quasilinear parabolic differential equation, and construct a linear three-level finite difference scheme on a nonuniform grid. The uniform convergence in the sense of discrete L~2 norm is proved and numerical examples are presented.     

Numerical methods for parabolic equation with a small parameter in time variable

In this paper,we discuss the parabolic equation with a small parameter on thederivative in time variable.We construct difference scheme on the non-uniform meshaccording to Bakhvalov,and prove the one-order uniform convergence of this scheme.Numerical results are presented.     

Instability of solution for the fourth order linear differential equation with varied coefficient

In this paper,we give some sufficient conditions of the instability for the fourth order linear differential equation with varied coefficient,at least one of the characteristic roots of which has positive real part,by means of Liapunov’s second method.     

色散方程的高稳定性两层四点显格式的单点精细积分法

基于单点精细积分的思想,对色散方程Ｕｔ＝ａＵｘｘｘ构造了一类高稳定性的两层四点显式差分格式,其局部截断误差为Ｏ（τ＋ｈ）稳定性条件为│Ｒ│＝│ａτ／ｈ＾３│≤ｆ（β）,对任意正实数β为单调递增函数,它们不仅显著地改善了同类格式的稳定性条件│Ｒ│≤０．２５而且也优于众多三层多点（５点或５点以上）显格式的稳定性条件。     

The linear approximation of the line continuous distribution method of singularities in creeping motion

The linear approximation of the line continuous distribution method of singularities is proposed to treat the creeping motion of the arbitrary prolate axisymmetrical body. The analytic expressions in closed form for the flow field are obtained. The numerical results for the proiate spheroid and Cassini oval demonstrate that the convergence and the accuracy of the proposen method are better that the constant density approximation. Furthermore, it can be applied to greater slender ratio. In this paper the example is yielded to show that the linear approximation of the singularities for the density on the partitioned segments can be utilized to consider the creeping motion of the arhitrary pointed prolate axisymmetrical body.     

色散方程的高稳定性三层五点显格式的广义单点精细积分法

基于文（１）中的单点精细积分方法,对色散方程Ｕｔ＝ａＵｘｘｘ提出了一种构造高稳定性三层五点（蛙跳）显格式的广义单点精细积分法,文中格式的局部截断误差为Ｏ（ｘ＾２＋ｈ＾２）,而稳定性条件为｜Ｒ｜≤ｇ（β）（其中ｇ对任意正实数是单调递增函数）,同时类格式中最好的。     

On the numerical solution of the Fokker-Planck equation for nonlinear stochastic systems

The finite element method is applied to the solution of the transient Fokker-Planck equation for several often cited nonlinear stochastic systems accurately giving, for the first time, the joint probability density function of the response for a given initial distribution. The method accommodates nonlinearity in both stiffness and damping as well as both additive and multiplicative excitation, although only the former is considered herein. In contrast to the usual approach of directly solving the backward Kolmogorov equation, when appropriate boundary conditions are prescribed, the probability density function associated with the first passage problem can be directly obtained. Standard numerical methods are employed, and results are shown to be highly accurate. Several systems are examined, including linear, Duffing, and Van der Pol oscillators.     

粘性可压混合层时间稳定性对称紧致差分求解

基于可压扰动方程组的一阶改型 ,将高精度对称紧致格式引入边值法数值线性稳定性分析。对所获非线性离散特征值问题给出了一个通用形式二阶迭代局部算法 ,实现了时间模式和空间模式的统一求解 ,并将扰动特征值及其特征函数同时得到。据此分析了可压平面自由混合层时间稳定性 ,涉及二维 /三维扰动波、粘性 /无粘扰动波、第一 /第二模态、特征函数、伪特征值谱等。研究表明 ,压缩性效应和粘性效应对最不稳定扰动波数和增长率呈相似的减抑作用 ;在 Mc=1附近 ,从高波数段开始 ,粘性效应可强化二维不稳定扰动波由第一模态向第二模态的过渡     

ON CAUCHY PROBLEMS FOR THE RLW EQUATION IN TWO SPACE DIMENSIONS

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｓｙｓｔｅｍｏｆｔｈｅｎｏｎｌｉｎｅａｒｄｉｓｐｅｒｓｉｖｅ ,ｔｈｅｐａｐｅｒｓ [1 ]ａｎｄ [2 ]ｈａｖｅｓｔｕｄｉｅｄｔｈｅｍｏｄｅｌｅｑｕａｔｉｏｎｏｆｓｉｍｐｌｅｗａｖｅｓｐｒｏｐａｇａｔｉｏｎｏｆｌｏｎｇｗａｖｅ ,ｕｔ+αｕｘ+ βｕｕｘ-γｕｘｘｔ=0　　ｘ∈Ｒ ,ｔ≥ 0ｉｓｃａｌｌｅｄｔｈｅＲＬＷｅｑｕａｔｉｏｎ .ＳＨＡＮＧ[3]ｏｂｔａｉｎｅｄｔｈｅｅｘａｃｔｓｏｌｉｔａｒｙｗａｖｅｓｏｌｕｔｉｏｎｓｏｆｔｈｅｔｗｏｄｉｍｅｎｓｉｏｎａｌＲＬＷｅｑｕａｔｉｏｎ .Ｉｎ…     

On cauchy problems for the RLW equation in two space dimensions

A cnoidal wave solution of the two dimensional RLW equation of are obtained by elliptic integral method, and the some estimations the uniqueness and the stability of the periodic solution with both x, y to the Cauchy problem are proved by the priori estimations. Biography: Huang Zheng-hong (1956-)     

On group classification of the spatially homogeneous and isotropic Boltzmann equation with sources II

A previous paper by the authors (Grigoriev and Meleshko, 2012 [4]) was devoted to group analysis of the equation for the power moment generating function of a solution of the Boltzmann kinetic equation with sources. An approach developed earlier by Grigoriev and Meleshko (1986 [2]) was employed for finding the admitted Lie group. This approach allowed to correct Nonenmacher׳s results (1984, [1]) and to perform a partial group classification of the considered equation with respect to a source function. The present paper completes this group classification by an efficient algebraic method.     

On the nonlinear Riemann problems for general first elliptic systems in the plane

IntroductionManyproblemsinmechanicsandmechanicalengineeringmaybeformulatedintoboundaryvalueproblemsforfirst_orsecond_orderellipticsystems.Lotsofscholarsandtheauthorsstudiedthem ( [1～ 6] ) .InthispaperwediscussthenonlinearRiemannproblemforgeneralsystemsofthefirst_orderlinearandquasi_linearequationsintheplane.1　TheNonlinearRiemannProblemforGeneralLinearEquationLetG beamultiplyconnecteddomaininthecomplexplaneEthatisboundedbyafinitenumberofclosed ,nonintersectingC1,αcurvesΓk,k=0 ,… ,mwit…     

On the stability of finite difference method for solving three-dimensional unsteady gasdynamic equations with artificial viscosity terms

The artificial viscosity method for three—dimensional unsteady gas flow is developed. The stability of finite difference scheme in this case is investigated. The necessary and sufficient conditions for the stability are obtained; these conditions formally agree with the two-dimensional result in Rusanov's paper.