THE OVER-RELAXATION FACTOR IN THE NUMERICAL SOLUTION OF THE OMEGA EQUATION

DAVID W. STUART U.S. Naval Postgraduate School, Monterey, Calif.

Search for other papers by DAVID W. STUART in
Current site
Google Scholar
PubMed
Close
and
CDR. THOMAS H. R. O'NEILL USN Office of the Naval Weather Service, Washington, D.C.

Search for other papers by CDR. THOMAS H. R. O'NEILL in
Current site
Google Scholar
PubMed
Close
Full access

Abstract

Results of tests for the optimum over-relaxation coefficients in the numerical relaxation of the omega equation are presented. One case considers a strong upper-level development for tests on a fixed grid using one-, two-, and three-dimensional forms of the omega equation. In the other case of a “classical storm” the omega equation is relaxed in its three-dimensional form using several different horizontal grids.

For the one- and two-dimensional tests, the relaxation scheme agreesv ery well with theory. In the three-dimensional tests, the observed over-relaxation coefficients are found to be less than the values given by the theory for all grid sizes considered. A sharp cut-off is found to occur shortly after the optimum over-relaxation value is reached regardless of the number of dimensions of the equation or the size of the grid.

On leave of absence from Florida State University.

Abstract

Results of tests for the optimum over-relaxation coefficients in the numerical relaxation of the omega equation are presented. One case considers a strong upper-level development for tests on a fixed grid using one-, two-, and three-dimensional forms of the omega equation. In the other case of a “classical storm” the omega equation is relaxed in its three-dimensional form using several different horizontal grids.

For the one- and two-dimensional tests, the relaxation scheme agreesv ery well with theory. In the three-dimensional tests, the observed over-relaxation coefficients are found to be less than the values given by the theory for all grid sizes considered. A sharp cut-off is found to occur shortly after the optimum over-relaxation value is reached regardless of the number of dimensions of the equation or the size of the grid.

On leave of absence from Florida State University.

Save