학술논문

Uniform a priori estimates for singularly perturbed elliptic equations in multidimensions.
Document Type
Journal
Author
Dörfler, W. (D-FRBG-A) AMS Author Profile
Source
SIAM Journal on Numerical Analysis (SIAM J. Numer. Anal.) (19990101), 36, no.~6, 1878-1900. ISSN: 0036-1429 (print).eISSN: 1095-7170.
Subject
35 Partial differential equations -- 35B Qualitative properties of solutions
  35B25 Singular perturbations

76 Fluid mechanics -- 76M Basic methods in fluid mechanics
  76M10 Finite element methods
Language
English
Abstract
Summary: ``We consider a linear singularly perturbed elliptic equation on a bounded domain in ${\bf R}^n$. This equation serves as a model for the interplay between the transport term and a relatively small viscosity term in some problems of mathematical physics. We establish a~priori estimates that hold uniformly in the small parameter. From this one can prove an abstract a~priori error estimate for the discretization with conforming finite elements. For globally directed transport fields we establish a new type of anisotropic a~priori estimate for the solution. In the case of $\Omega=(0,1)^2$ we prove a~priori estimates for certain higher-order derivatives in isotropic as well as anisotropic norms. In a subsequent paper we will apply these results to show uniform convergence of an exponentially fitted method on rectangular grids.''