Record Display for the EPA National Library Catalog


OLS Field Name OLS Field Data
Main Title Evaluation of Two Numerical Integrator Schemes.
Author Patrinos, A. A. N. ; Leach, M. J. ;
CORP Author Brookhaven National Lab., Upton, NY.;Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Sciences Research Lab.
Year Published 1984
Report Number EPA/600/3-84/112;
Stock Number PB85-138196
Additional Subjects Atmospheric diffusion ; Diffusion theory ; Advection ; Air pollution ; Mathematical models ; Numerical integration ; Approximation ; Polynomials ; Evaluation ; Atmospheric dispersion ; Pseudospectral methods
Library Call Number Additional Info Location Last
NTIS  PB85-138196 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 06/23/1988
Collation 43p
Two numerical integrators of the advection-diffusion equation used in air pollution simulations were tested in the framework of an evaluation methodology. The schemes were an integrator based on a polynomial approximation algorithm and a version of the pseudospectral integrator. The evaluation methodology included two test cases: the transport of a spline puff and a constant point source. Testing criteria included accuracy, conservation, and efficiency. Accuracy was assessed with the use of 'norms' which used the exact analytical solution values. The 'polynomial' integrator demonstrated superior consistency in its performance and generally better accuracy. The cost was, however, about 2.5 times that of the pseudospectral one. The pseudospectral integrator with its expanding mesh displayed deteriorating accuracy whenever the signal approached the boundaries. Simple filtering algorithms have failed to effectively control this problem.