When using Laguerre and Hermite spectral methods to numerically solve PDEs in unbounded domains, the number of collocation points assigned inside region interest is often insufficient, parti...

We extend a large-eddy simulation (LES) methodology, based on using the spectral vanishing viscosity (SVV) method to stabilize spectral collocation approximations, from the Cartesian to the cylindrical geometry. The capabilities of the SVV–LES approach are illustrated for two very different physical problems: (1) the influence of thermal stratification on the wake of a cylinder, and (2) the ins...

In recent years, there has been a growing interest in analyzing and quantifying the effects of random inputs in the solution of ordinary/partial differential equations. To this end, the spectral stochastic finite element method (SSFEM) is the most popular method due to its fast convergence rate. Recently, the stochastic sparse grid collocation method has emerged as an attractive alternative to ...

For the known spectral methods (Galerkin, Tau, Collocation) the condition number behaves like 0(N4) (N: maximal degree of polynomials). We introduce a spectral method with an 0(N2) condition number. The advantages with respect to propagation of rounding errors and preconditioning are demonstrated. A direct solver for constant coefficient problems is given. Extensions to variable coefficient pro...

We propose and analyze a C spectral element method for a model eigenvalue problem with discontinuous coefficients in the one dimensional setting. A super-geometric rate of convergence is proved for the piecewise constant coefficients case and verified by numerical tests. Furthermore, the asymptotical equivalence between a Gauss-Lobatto collocation method and a spectral Galerkin method is establ...

The recognition and the calculation of all branches of solutions of the nonlinear boundary value problems is difficult obviously. The complexity of this issue goes back to the being nonlinearity of the problem. Regarding this matter, this paper considers steady state reactive transport model which does not have exact closed-form solution and discovers existence of dual or triple solutions in so...