A meshfree method for the numerical solution of the RLW equation

In this paper, we present a meshfree technique for the numerical solution of the regularized long wave (RLW) equation. This approach is based on a global collocation method using the radial basis functions (RBFs). Different kinds of RBFs are used for this purpose. Accuracy of the new method is tested in terms of _L2$L_2$ and _L∞$L_{\infty }$ error norms. In case of non-availability of the exact solution, performance of the new method is compared with existing methods. Stability analysis of the method is established. Propagation of single and double solitary waves, wave undulation, and conservation properties of mass, energy and momentum of the RLW equation are discussed.     

Fourier-Chebyshev pseudospectral method for two-dimensional vorticity equation

Summary A Fourier-Chebyshev pseudospectral scheme is proposed for two-dimensional unsteady vorticity equation. The generalized stability and convergence are proved strictly. The numerical results are presented.     

Meshless method of lines for the numerical solution of generalized Kuramoto-Sivashinsky equation

In this paper, the numerical solution of the generalized Kuramoto-Sivashinsky equation is presented by meshless method of lines (MOL). In this method the spatial derivatives are approximated by radial basis functions (RBFs) giving an edge over finite difference method (FDM) and finite element method (FEM) because no mesh is required for discretization of the problem domain. Only a set of scattered nodes is required to approximate the solution. The numerical results in comparison with exact solution using different radial basis functions (RBFs) prove the efficiency and accuracy of the method.     

Cosine expansion-based differential quadrature method for numerical solution of the KdV equation

Numerical solution of the Korteweg–de Vries equation is obtained using space-splitting technique and the differential quadrature method based on cosine expansion (CDQM). The details of the CDQM and its implementation to the KdV equation are given. Three test problems are studied to demonstrate the accuracy and efficiency of the proposed method. Accuracy and efficiency are discussed by computing the numerical conserved laws and L₂, L_∞ error norms.     

A numerical method for finding positive solution of diffusive logistic equation

Using a numerical methods based on sub–super solution, we will find positive solution for the diffusive logistic equation Δu+au-bu²=0 for xΩ, with Dirichlet boundary condition.     

Galerkin method for the numerical solution of the RLW equation using quintic B-splines

The regularized long wave equation (RLW) is solved numerically by using the quintic B-spline Galerkin finite element method. The same method is applied to the time-split RLW equation. Comparison is made with both analytical solutions and some previous results. Propagation of solitary waves, interaction of two solitons are studied.     

FOURIER－CHEBYSHEV SPECTRAL METHOD FOR SOLVING THREE－DIMENSIONAL VORTICITY EQUATION

ＦＯＵＲＩＥＲ－ＣＨＥＢＹＳＨＥＶＳＰＥＣＴＲＡＬＭＥＴＨＯＤＦＯＲＳＯＬＶＩＮＧＴＨＲＥＥ－ＤＩＭＥＮＳＩＯＮＡＬＶＯＲＴＩＣＩＴＹＥＱＵＡＴＩＯＮＧＵＯＢＥＮＹＵ（郭本瑜）；ＬＩＪＩＡＮ（李健）；ＭＡＨＥＰＩＮＧ（马和平）（Ｄｅｐａｒｔｍｅｎｔｏ...     

CHEBYSHEV SPECTRAL-FINITE ELEMENTMETHOD FOR THREE-DIMENSIONALVORTICITY EQUATION

1.TheSchemesInthispaper,weconsidercombinedChebyshevspectraLfiniteelementmethodforthreedimensionalunsteadyvorticityequation.LetQbeaconvexpolygoninRZandIbetheinterval(--1,1).x~(xl,x2)andfi={(x,y)/xEQ,yEI}.Theboundaryoffiisdenotedbyoff.Denotethevorticityvectorandstreamvectorby(andoprespectively.Theircomponentsaref(q)andop(q),q=1,2,3.Letu>0bethekineticviscosity.fi,fZandfoaregivenvectors.Thethree-dimensionalvorticityequationisAssumethattheboundaryisafixednon-slipwallandsoop=oonafl.FOrsimpli…     

A four-step method for the numerical solution of the Schrödinger equation

A new four-step exponentially-fitted method is developed in this paper. The expressions for the coefficients of the method are found such as to ensure the optimal approximation to the eigenvalue Schrödinger equation (i.e., equivalent to positive energy).     

The method of step by step inversion for numerical solution of the Biharmonic equation

The research was supported by the Russian Foundation for Fundamental Research (Grant 93-01-00494).     

Algorithms for numerical solution of the modified equal width wave equation using collocation method

Quintic B-spline collocation algorithms for numerical solution of the modified equal width wave (MEW) equation have been proposed. The algorithms are based on Crank–Nicolson formulation for time integration and quintic B-spline functions for space integration. Quintic B-spline collocation method over the finite intervals is also applied to the time split MEW equation and space split MEW equation. Results for the three algorithms are compared by studying the propagation of the solitary wave, interaction of the solitary waves, wave generation and birth of solitons.     

Error estimation of spectral method for solving three-dimensional vorticity equation

Much work has been done for spectral scheme of P.D.E. (see [1]). Recently the author proposed a technique to prove the strict error estimation of spectral scheme for non-linear problems such as K.D.V.-Burgers' equation, two-dimensional vorticity equation and so on ([2]–[4]). In this paper we generalize this technique into three-dimensional vorticity equation. Under some conditions these error estimations imply convergence. The more smooth the solution of P.D.E., the more accurate the approximate solution.The author is     

A starting method for the numerical solution of Volterra's integral equation of the second kind

The acquisition of starting values is one of the chief difficulties encountered in computing a numerical solution of Volterra's integral equation of the second kind by a multi-step method. The object of this note is to present a procedure which is derived from certain quadrature formulas and which provides these starting values, to provide a sufficient condition for the approximate solution to be unique, to bound the approximate solution and the error, and to give a numerical example.     

Hopscotch method: The numerical solution of the Frank-Kamenetskii partial differential equation

Numerical solutions to the Frank-Kamenetskii partial differential equation modelling a thermal explosion in a cylindrical vessel are obtained using the hopscotch scheme. We observe that a nonlinear source term in the equation leads to numerical difficulty and hence adjust the scheme to accommodate such a term. Numerical solutions obtained via MATLAB, MATHEMATICA and the Crank-Nicolson implicit scheme are employed as a means of comparison. To gain insight into the accuracy of the hopscotch scheme the solution is compared to a power series solution obtained via the Lie group method. The numerical solution is also observed to converge to a well-known steady state solution. A linear stability analysis is performed to validate the stability of the results obtained.     

A numerical method for the Benjamin-Ono equation

This paper is concerned with the numerical solution of the Cauchy problem for the Benjamin-Ono equationu _t +uu _x −Hu _xx =0, whereH denotes the Hilbert transform. Our numerical method first approximates this Cauchy problem by an initial-value problem for a corresponding 2L-periodic problem in the spatial variable, withL large. This periodic problem is then solved using the Crank-Nicolson approximation in time and finite difference approximations in space, treating the nonlinear term in a standard conservative fashion, and the Hilbert transform by a quadrature formula which may be computed efficiently using the Fast Fourier Transform.     

A consistent numerical method for the solution of the Boltzmann equation for inelastic and reactive scattering

A spatially homogeneous gas mixture is considered in which inelastic collisions and chemical reactions may occur. The corresponding Boltzmann equation is transformed to a system of scalar kinetic equations. A method is presented for the numerical solution of this set of integro-differential equations. It is shown that the method is consistent with the Boltzmann equation in the sense that it is conserving and preserves theH-theorem, that the equilibrium solution is a discretized Maxwellian, and that the equilibrium densities satisfy the generalized law of mass action.

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Zusammenfassung Es wird ein räumlich homogenes Gasgemisch betrachtet, dessen Moleküle durch elastische und inelastische Stöße, sowie durch chemische Umwandlungsprozesse miteinander wechselwirken. Die entsprechende Boltzmann-Gleichung wird in ein System skalarer kinetischer Gleichungen umgeformt. Eine Methode zur numerischen Lösung dieses Systems von Integrodifierentialgleichungen wird präsentiert. Wie sich zeigen läßt, ist das numerische Verfahren konsistent, d.h. es gelten die Erhaltungssätze, einH-Theorem und ein verallgemeinertes Massenwirkungsgesetz und als Gleichgewichtslösung ergibt sich eine diskretisierte Maxwell-Verteilung.

     

Error analysis for numerical solution of fractional differential equation by Haar wavelets method

In this paper, an exact upper bound is presented through the error analysis to solve the numerical solution of fractional differential equation with variable coefficient. The fractional differential equation is solved by using Haar wavelets. From the exact upper bound, we can draw a conclusion easily that the method is convergent. Finally, we also give some numerical examples to demonstrate the validity and applicability of the method.     

A fourth algebraic order exponentially-fitted Runge-Kutta method for the numerical solution of the Schrodinger equation

An exponentially-fitted Runge–Kutta method for the numericalintegration of the radial Schrödinger equation is developed.Theoretical and numerical results obtained for the well knownWoods–Saxon potential show the efficiency of the new method.     

Chebyshev pseudospectral method for computing numerical solution of convection–diffusion equation

A method for computing highly accurate numerical solutions of 1D convection–diffusion equations is proposed. In this method, the equation is first discretized with respect to the spatial variable, transforming the original problem into a set of ordinary differential equations, and then the resulting system is integrated in time by the fourth-order Runge–Kutta method. Spatial discretization is done by using the Chebyshev pseudospectral collocation method. Before describing the method, we review a finite difference-based method by Salkuyeh [D. Khojasteh Salkuyeh, On the finite difference approximation to the convection–diffusion equation, Appl. Math. Comput. 179 (2006) 79–86], and, contrary to the proposal of the author, we show that this method is not suitable for problems involving time dependent boundary conditions, which calls for revision. Stability analysis based on pseudoeigenvalues to determine the maximum time step for the proposed method is also carried out. Superiority of the proposed method over a revised version of Salkuyeh’s method is verified by numerical examples.     

A numerical verification method for a periodic solution of a delay differential equation

We describe a numerical method with guaranteed accuracy to enclose a periodic solution for a system of delay differential equations. Using a certain system of equations corresponding to the original system, we derive sufficient conditions for the existence of the solution, the satisfaction of which can be verified computationally. We describe the verification procedure in detail and give a numerical example.