On cubic Padé Approximation to the exponential function and its application in solving diffusion-convection equation
نویسندگان
چکیده
Diagonal cubic Hermite-Padé approximation to the exponential function with coefficient polynomials of degree at most m is considered. Explicit formulas and differential equations are obtained for the coefficient polynomials. An exact asymptotic expression is obtained for the error function and it is also shown that these generalized Padé-type approximations can be used to asymptotically minimize the expressions on the unit disk. As an application, a class of local analytical difference schemes based on diagonal cubic Padé approximation for diffusion-convection equation with constant coefficients is proposed.
منابع مشابه
Finite integration method with RBFs for solving time-fractional convection-diffusion equation with variable coefficients
In this paper, a modification of finite integration method (FIM) is combined with the radial basis function (RBF) method to solve a time-fractional convection-diffusion equation with variable coefficients. The FIM transforms partial differential equations into integral equations and this creates some constants of integration. Unlike the usual FIM, the proposed method computes constants of integ...
متن کاملFinite Element Methods for Convection Diffusion Equation
This paper deals with the finite element solution of the convection diffusion equation in one and two dimensions. Two main techniques are adopted and compared. The first one includes Petrov-Galerkin based on Lagrangian tensor product elements in conjunction with streamlined upwinding. The second approach represents Bubnov/Petrov-Galerkin schemes based on a new group of exponential elements. It ...
متن کاملThe Method of Characteristics with Gradients and integrals
This paper is concerned with the Cubic Interpolation scheme CIP proposed by T. Yabe for the Galerkin Characteristic Method and the possibility of improving the precision of PDE solvers when the differentiated form of the equation is used. For convection diffusion equations a Lagrangian treatment of the convective term is analyzed for various approximations of the projection operator. It is foun...
متن کاملAn exponential spline for solving the fractional riccati differential equation
In this Article, proposes an approximation for the solution of the Riccati equation based on the use of exponential spline functions. Then the exponential spline equations are obtained and the differential equation of the fractional Riccati is discretized. The effect of performing this mathematical operation is obtained from an algebraic system of equations. To illustrate the benefits of the me...
متن کاملApplication of Tau Approach for Solving Integro-Differential Equations with a Weakly Singular Kernel
In this work, the convection-diffusion integro-differential equation with a weakly singular kernel is discussed. The Legendre spectral tau method is introduced for finding the unknown function. The proposed method is based on expanding the approximate solution as the elements of a shifted Legendre polynomials. We reduce the problem to a set of algebraic equations by using operational matrices....
متن کامل