A New Approach to Three-Dimensional Free-Surface Flow Modeling

by Jan J. Leendertse

Download

Full Document

FormatFile SizeNotes
PDF file 1.8 MB

Use Adobe Acrobat Reader version 10 or higher for the best experience.

Purchase

Purchase Print Copy

 FormatList Price Price
Add to Cart Paperback62 pages $23.00 $18.40 20% Web Discount

This report describes an efficient model for the computation of three-dimensional free-surface flows. For the time integration, two different approximations are used in succession. The advection term approximations depend on the flow direction and introduce stability into the computation. The gradients of the advection terms are generally computed directly, whereas the coefficients of the nonlinear terms must be computed by iteration. Experiments show that only two iterations are required. The finite difference approximations used in the computation are of the second order, and no time filtering or introduction of viscosity is required for stability. The timestep is limited by the accuracy desired in the results. In the formulation, it is assumed that the pressures are hydrostatic. A stability analysis that uses linearized coefficients in the nonlinear terms indicates that the computation method is unconditionally stable. To investigate the effect of different timesteps on model results, the author made several experiments that confirmed the analysis of the behavior of the computation method showing that the growth of disturbances with small wavelength and periods is inhibited. A model of a lake (IJsselmeer) showed that, with limited computer resources, effective three-dimensional flow and transport computations can be made.

This report is part of the RAND Corporation Report series. The report was a product of the RAND Corporation from 1948 to 1993 that represented the principal publication documenting and transmitting RAND's major research findings and final research.

Permission is given to duplicate this electronic document for personal use only, as long as it is unaltered and complete. Copies may not be duplicated for commercial purposes. Unauthorized posting of RAND PDFs to a non-RAND Web site is prohibited. RAND PDFs are protected under copyright law. For information on reprint and linking permissions, please visit the RAND Permissions page.

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.