%0 Journal Article
%A Leupi, Celestin
%A Altinakar, Mustafa Siddik
%D 2006
%I Begell House
%N 3
%P 363-375
%R 10.1615/IntJMultCompEng.v4.i3.60
%T 3D Finite Element Modeling of Free-Surface Flows with Efficient *k* − ε Turbulence Model and Nonhydrostatic Pressure
%U http://dl.begellhouse.com/journals/61fd1b191cf7e96f,2f8263727708f280,070c97402b22dd41.html
%V 4
%X Validation of three-dimensional (3D) finite element model for free-surface flow is conducted using a high-quality and high spatial resolution data set. The present research finds its motivation in the increasing need for efficient management of geophysical flows, such as estuaries (multiphase fluid flow) or natural rivers with the complicated channel geometry (e.g., strong channel curvature). A numerical solution is based on the unsteady Reynolds-averaged Navier-Stokes equations without conventional assumption of hydrostatic pressure. The eddy viscosity is calculated from the efficient *k* − ε turbulence model. The model uses implicit fractional step time stepping, and the characteristics method is used to compute the convection terms in the multilayer system (suitable for the vertical stratified fluid flow), in which the vertical grid is located at predefined heights and the number of elements in the water column depends on water depth. The lowermost and uppermost elements of variable height allow a faithful representation of the channel bed and the time-varying free surface, respectively. The model is applied to the 3D curved open channels flows for which experimental data are available for comparison. Computations with and without non-hydrostatic are compared for the same trench to test the validity of the conventional hydrostatic pressure assumption. Good agreement is found between numerical computations and experiments.
%8 2006-09-27