Description of the Optimized EPRF Multi-Layer Hydrodynamical-Numerical Model
Abstract
The multi-layer hydrodynamic-numerical (HN) model described here is a redesigned and optimized version of the multi-layer codes developed by the Environmental Prediction Research Facility (EPRF) using the finite difference scheme proposed and tested by Professor W. Hansen, University of Hamburg, Germany. The model described is written in FORTRAN IV for CDC computers. The model is divided into three phases linked by a single intermediate tape. Phase I, which initializes the intermediate tape by writing on it the computed symbolic water height field, the water depth fields at U and V points, and the time O water height and velocity fields, is run on EPRF's CDC 3100 computer. Phase II, which computes time and space dependent terms, is run on either the CDC 6500 or the CDC 7600. Phase III is used to analyze, display and compare printed and plotted model results. It also runs on EPRF's CDC 3100 computer and produces plots on a CALCOMP pen plotter. The optimized code has been designed to be independent of grid size and land-sea configuration so long as the maximum number of elements in the grid used does not exceed the assigned core. The model allows computation of currents in one to three uniform layers of different density water but limits diffusion processes to the surface layer. The optimized model tests have shown approximately a 50 percent reduction in CDC 7600 run times, an improvement of the Berkeley ITO: CPU ratio from 1.1 to .5:1, a 10 percent reduction in small core and a 70 percent reduction in large core usage.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1974
- Accession Number
- AD1222991
Entities
People
- R. A. Bauer